Konrad Ptaszynski - Academia.edu (original) (raw)
Papers by Konrad Ptaszynski
American Journal of Surgical Pathology, 2010
Cellular angiofibroma is a mesenchymal neoplasm that is characterized by a bland spindle cell com... more Cellular angiofibroma is a mesenchymal neoplasm that is characterized by a bland spindle cell component, morphologically reminiscent of spindle cell lipoma, and thick-walled vessels. The tumor occurs equally in men and women and usually arises in the inguino-scrotal or vulvovaginal regions. An earlier study of 51 cases from our group showed that the tumor follows a benign course without any tendency for recurrence. In 1 case, an intralesional microscopic nodule of pleomorphic liposarcoma was observed. The biologic significance of atypia or sarcomatous transformation in cellular angiofibroma remains uncertain. In this study, we characterized clinicopathologic features in 13 cases of cellular angiofibroma with morphologic atypia or sarcomatous transformation. Thirteen cases with atypia or sarcomatous transformation among 154 usual cellular angiofibromas identified between 1993 and 2009 were retrieved from consultation files. There were 12 females and 1 male ranging in age from 39 to 71 years (median age, 46 y). Tumor size ranged from 1.2 to 7.5 cm. In 11 cases, the tumors occurred in the vulva. One case each occurred in the paratesticular and hip regions. Most tumors were located in subcutaneous tissue. There were 4 cases of cellular angiofibroma with atypia. Three showed severely atypical cells as scattered foci within the cellular angiofibroma. One case showed a discrete nodule of atypical cells. There were 9 cases of cellular angiofibroma with morphologic features of sarcomatous transformation. In each case, abrupt transition to a discrete sarcomatous component was seen. Of these 9 cases, the sarcomatous component in 2 cases showed features of pleomorphic liposarcoma with multivacuolated lipoblasts readily identified. Three of these 9 cases showed discrete nodule(s) closely resembling atypical lipomatous tumor within usual cellular angiofibroma. In the remaining 4 cases, the sarcomatous component was composed of pleomorphic spindle cells arranged in various patterns. By immunohistochemistry, atypical cells and sarcomatous areas showed either multifocal or more diffuse p16 expression compared with either scattered or negative expression in the conventional cellular angiofibroma. The 3 cases with atypical lipomatous tumor-like areas were negative for MDM-2 and CDK4. Follow-up information was available for 7 patients (range from 2 to 75 mo; median: 14 mo). Six patients did not develop recurrence or metastasis. One patient died of metastatic carcinoma of unknown primary site 27 months after the diagnosis of cellular angiofibroma with sarcomatous transformation. Cellular angiofibroma with atypia or morphologic sarcomatous transformation occurs predominantly in the subcutaneous tissue of the vulva and, as yet, shows no evident tendency to recur based on limited clinical follow-up available for 7 cases. The sarcomatous component can show variable features including atypical lipomatous tumor, pleomorphic liposarcoma, and pleomorphic sarcoma NOS. Overexpression of p16 in the atypical cells and sarcomatous component suggests a possible underlying molecular mechanism.
The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Ewing... more The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Ewing sarcoma (ES) is a group of highly aggressive small round cell tumors of bone or soft tissue with high metastatic potential and low cure rate. ES tumors are associated with a rapid osteolysis and necrosis. The currently accepted clinical prognostic parameters do not accurately predict survival of high-risk patients. Moreover, neither the subtype of EWS–FLI1/ERG in the tumor, nor the detection of fusion transcripts in the peripheral blood (PB) samples, has prognostic value in ES patients. We evaluated the prevalence of circulating tumor cells (CTCs) in 34 adult ES patients. Since CTCs were confirmed in only small subset of patients, we further explored the expression profiles of PB leukocytes using a panel of genes associated with immune system status and increased tumor invasive-
Journal of Clinical Oncology, 2012
10538 Background: EFTs are characterized by chromosomal translocations leading to formation of on... more 10538 Background: EFTs are characterized by chromosomal translocations leading to formation of oncogenic EWSR1-FLI1 fusion gene in 85-90% of cases. The aim of the study was to detect circulating tumor cells (CTCs) carrying EWSR1-FLI1 fusion transcript in peripheral blood and assess their added value to standard diagnostic procedures and utility as a prognostic marker in EFTs. Methods: 10mL of whole blood was collected from 35 untreated adult EFTs patients at the diagnosis (period: 2008-2011, median age 27 years) and 13 healthy controls. 13 patients presented metastatic disease (M1) at the diagnosis. Nested RT-PCR was applied in triplicate for the detection of EWSR1-FLI1 transcript. Blood specimen was regarded CTC-positive when at least 2 out of 3 nested RT-PCR assays were positive and results were confirmed by sequencing. FISH assay for EWSR1 rearrangement was performed on FFPE tumor tissue in 28 available cases. Median follow-up was 16 months. Results: EWSR1-FLI1 transcript was det...
Journal of Clinical Oncology, 2013
e22046 Background: EFTs are characterized by oncogenic EWSR1-FLI1 fusion gene, which can be detec... more e22046 Background: EFTs are characterized by oncogenic EWSR1-FLI1 fusion gene, which can be detected in 85-90% of tumors and in 20-70% of peripheral blood specimens. It has been previously reported that downregulation of CDH2 (encoding N-cadherin) and overexpression of CDT2 [also known as DTL, encoding denticleless homolog (Drosophila)]in EFTs tumors are associated with poor prognosis. The aim of the study was to evaluate the expression levels of these markers in the circulating tumor cells and assess their utility as prognostic markers in EFTs. Methods: 10mL of PB was collected from 24 untreated adult EFTs patients at the diagnosis (period: 2009-2011, median age 30 years). 9 blood specimens from healthy individuals, and 5 untreated frozen EFTs tumor samples were used as controls. 8 EFTs patients presented metastatic disease (M1) at the diagnosis and 5 patients died during the follow-up period. Median follow-up was 22 months. Quantitative reverse transcription PCR (qRT-PCR) for CDH2...
Onkologia W Praktyce Klinicznej, 2010
Zalecenia postępowania diagnostyczno-terapeutycznego u dorosłych chorych na pierwotne nowotwory z... more Zalecenia postępowania diagnostyczno-terapeutycznego u dorosłych chorych na pierwotne nowotwory złośliwe kości Recommendations for diagnostics and therapy of adult patients with malignant primary bone tumors STRESZCZENIE Mięsaki kości u dorosłych stanowią heterogenną grupę bardzo rzadkich nowotworów pochodzenia mezenchymalnego (poniżej 0,5% nowotworów złośliwych u dorosłych). Pod względem klinicznym mięsaki kości można podzielić na mięsaki wrzecionowatokomórkowe (obejmujące mięsaki kościopochodne, większość chrzęstniakomięsaków i inne rzadsze podtypy) oraz drobnokomórkowe (głównie rodzina mięsaków Ewinga). Prawidłowe rozpoznanie i skuteczne leczenie skojarzone pierwotnych nowotworów kości są sumą współpracy radiologów, chirurgów onkologów i chirurgów ortopedów, onkologów klinicznych, radioterapeutów, rehabilitantów, patologów, specjalistów medycyny nuklearnej i biologów molekularnych. Bezwzględnym warunkiem w diagnostyce i leczeniu pierwotnych nowotworów złośliwych kości jest wielodyscyplinarna współpraca wielospecjalistyczna w doświadczonych ośrodkach. Polepszenie diagnostyki mięsaków kości, wprowadzenie zasad terapii skojarzonej i postęp technologiczny spowodowały rozszerzenie wskazań do stosowania operacji oszczędzających kończynę oraz poprawiły odległe wyniki leczenia.
International journal of clinical and experimental pathology, 2015
The study compares detection rates of oncogenic BRAF mutations in a homogenous group of 236 FFPE ... more The study compares detection rates of oncogenic BRAF mutations in a homogenous group of 236 FFPE cutaneous melanoma lymph node metastases, collected in one cancer center. BRAF mutational status was verified by two independent in-house PCR/Sanger sequencing tests, and the Cobas® 4800 BRAF V600 Mutation Test. The best of two sequencing approaches returned results for 230/236 samples. In 140 (60.9%), the mutation in codon 600 of BRAF was found. 91.4% of all mutated cases (128 samples) represented p.V600E. Both Sanger-based tests gave reproducible results although they differed significantly in the percentage of amplifiable samples: 230/236 to 109/143. Cobas generated results in all 236 cases, mutations changing codon V600 were detected in 144 of them (61.0%), including 5 not amplifiable and 5 negative in the standard sequencing. However, 6 cases positive in sequencing turned out to be negative in Cobas. Both tests provided us with the same BRAF V600 mutational status in 219 out of 230 ...
Polish journal of pathology : official journal of the Polish Society of Pathologists, 2009
Synovial sarcoma (SyS) occurs mostly in young adults and is characterized by an aggressive course... more Synovial sarcoma (SyS) occurs mostly in young adults and is characterized by an aggressive course. Combined treatment including chemotherapy, radiotherapy and surgical excision of the tumour is still not satisfactory, with mean 5-year survival of 30-50%. New targeted treatment options have appeared recently, e.g. HER2 and EGFR antagonists. Initial studies have revealed immunohistochemical overexpression of the EGFR in SyS; therefore trials with EGFR antagonist therapy have commenced. The aim of our study was to evaluate the status of HER2, EGFR and TOPIIA in SyS before and after combined therapy. Immunohistochemistry and FISH tests were performed. Significant discrepancies between protein expression and gene status were found. The authors discuss the potential reasons for that phenomenon.
European journal of dermatology : EJD, 2013
ejd.2013.1992 Auteur(s) : Katarzyna Wiater1 wiater.katarzyna@gmail.com, Marcin Zdzienicki1, Tadeu... more ejd.2013.1992 Auteur(s) : Katarzyna Wiater1 wiater.katarzyna@gmail.com, Marcin Zdzienicki1, Tadeusz Morysinski1, Hanna Kosela1, Anna Klimczak1, Mariusz Obrebski2, Konrad Ptaszynski3, Piotr Rutkowski1 1 Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie Memorial Cancer Center, Roentgena Str. 5, 02-781 Warsaw, Poland 2 Department of Surgery, Regional Hospital Plock, Poland 3 Department of Pathology, The Medical Center of Postgraduate Education, Warsaw, Poland In April [...]
Polish journal of pathology : official journal of the Polish Society of Pathologists, 2009
Small round cell tumours (SRCT) of bone and soft tissue constitute a heterogeneous group of neopl... more Small round cell tumours (SRCT) of bone and soft tissue constitute a heterogeneous group of neoplasms with similar histological and cytological features. Immunohistochemical studies with panels of antibodies are necessary in order to make the diagnosis. A molecular testing is helpful in many cases. To assess the value of IHC and FISH tests in the differential diagnosis of SRCT. The material was obtained from patients diagnosed and treated at the Maria Skłodowska-Curie Memorial Cancer Center-Institute in Warsaw between February 2003 and March 2009. One hundred and thirty one patients with the initial diagnosis of SRCT of bone or soft tissue were qualified to the investigation. The material from the primary tumour was obtained by an open or core biopsy in all the patients. During the treatment the patients were monitored, the local recurrence and the distant metastases were reported. The IHC study was performed routinely using wide panels of antibodies. FISH tests: EWSR1, SS18 (SYT), ...
Przegla̧d lekarski, 2003
Neuroblastoma is the third most common neoplasm of childhood. About 70% of cases occurs by 5 year... more Neuroblastoma is the third most common neoplasm of childhood. About 70% of cases occurs by 5 years old and around 95% cases in the patients younger than 10 years old. Neuroblastoma is part of the spectrum of the family neuroblastic tumors. The family consists of heterogeneous group of tumors, difficult to classify. Additionally some cases of neuroblastoma show tendency to self-maturation and regression. The family consists of neuroblastoma (NB), ganglio-neuroblastoma (GNB) and ganglineuroma (GN). In recent years there has been considerable development in the classification concepts from purely histological to clinico-pathological one. These schemes include clinical, pathological and molecular features od tumors which allow more accurate prognostication.
![Research paper thumbnail of [Nr 58] Wyniki leczenia chorych na miejscowo zaawansowane mięsaki tkanek miękkich kończyn/tułowia z zastosowaniem hipofrakcjonowanej przedoperacyjnej radioterapii](https://attachments.academia-assets.com/93927976/thumbnails/1.jpg)
](Zeszyty Naukowe WCO, Letters in Oncology Science, 2013
Tumor Biology, 2010
Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous cell epithelia and in squa... more Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous cell epithelia and in squamous cell carcinomas (SCC). Two nearly identical genes encode the inhibitory serpins SCCA1 (SERPINB3) and SCCA2 (SERPINB4). Serum levels of SCCA are elevated in patients with benign skin diseases and in patients with SCC. SCCA, used for the monitoring of SCC patients, presents no satisfactory diagnostic specificity. As we have shown previously, the reverse transcription polymerase chain reaction (RT-PCR)-based SCCA messenger RNA (mRNA) testing aimed at detecting disseminated cancer cells may be hampered by the false-positive results due to SCCA expression in activated peripheral blood mononuclear cells (PBMC). The aim of this study was to assess the expression of SCCA at mRNA and protein levels in cultured normal PBMC, compared to that in vulvar SCC (VSCC) samples. High SCCA concentrations were found in vulvar tumours and in metastatic lymph nodes, while negative inguinal lymph nodes from the same patients often presented significantly less SCCA. In normal activated PBMC, the level of SCCA protein was the lowest. At the mRNA level SCCA was detectable in normal PBMC even in cultures with no mitogen stimulation, but only by the nested RT-PCR, contrary to VSCC samples found to be SCCA positive already in one-step PCR. Both SCCA1 and SCCA2 transcripts were present in cultured PBMC; SCCA1 was expressed at a higher level than SCCA2. In conclusion, both SCCA forms are detectable in normal
Laboratory Investigation, 2006
In this paper, we present whole-organ histologic and genetic mapping studies using hypervariable ... more In this paper, we present whole-organ histologic and genetic mapping studies using hypervariable DNA markers on chromosome 13 and then integrate the recombination-and single-nucleotide polymorphic sites (SNPs)-based deletion maps with the annotated genome sequence. Using bladders resected from patients with invasive urothelial carcinoma, we studied allelic patterns of 40 microsatellite markers mapping to all regions of chromosome 13 and 79 SNPs located within the 13q14 region containing the RB1 gene. A whole-organ histologic and genetic mapping strategy was used to identify the evolution of allelic losses on chromosome 13 during the progression of bladder neoplasia. Markers mapping to chromosomal regions involved in clonal expansion of preneoplastic intraurothelial lesions were subsequently tested in 25 tumors and 21 voided urine samples of patients with bladder cancer. Four clusters of allelic losses mapping to distinct regions of chromosome 13 were identified. Markers mapping to the 13q14 region that is flanked by D13S263 and D13S276, which contains the RB1 gene, showed allelic losses associated with early clonal expansion of intraurothelial neoplasia. Such losses could be identified in approximately 32% bladder tumor tissue samples and 38% of voided urines from patients with bladder cancer. The integration of distribution patterns of clonal allelic losses revealed by the microsatellite markers with those obtained by genotyping of SNPs disclosed that the loss within an approximately 4-Mb segment centered around RB1 may represent an incipient event in bladder neoplasia. However, the inactivation of RB1 occurred later and was associated with the onset of severe dysplasia/ carcinoma in situ. Our studies provide evidence for the presence of critical alternative candidate genes mapping to the 13q14 region that are involved in clonal expansion of neoplasia within the bladder antecedent to the inactivation of the RB1 gene.
Laboratory Investigation, 2007
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestina... more Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestinal tract. GISTs range from benign indolent neoplasms to highly malignant sarcomas. Gain-of-function mutations of tyrosine kinase receptors, KIT or PDGFRA, have been identified in most GISTs. In this study, we report 36 GIST patients whose tumors had homozygous KIT exon 11 mutations detected by direct sequencing of PCR products. Loss of heterozygosity in KIT locus and other chromosome 4 loci were documented in majority of these tumors. However, fluorescence in situ hybridization with KIT locus-specific probe and chromosome 4 centromeric enumeration probe showed no evidence of KIT hemizygosity in a majority of analyzed cases. These findings are consistent with duplication of chromosome 4 with KIT mutant allele. Homozygous KIT exon 11 mutations were found in 33 primary tumors and 7 metastatic lesions. In two cases, shift from heterozygosity to homozygosity was documented during tumor progression being present in metastases, but not in primary tumors. Among primary GISTs, there were 16 gastric, 18 intestinal and 2 from unknown locations. An average primary tumor size was 12 cm and average mitotic activity 32/50 HPFs. Out of 32 tumors 29 (90.6%) with complete clinicopathologic data were diagnosed as sarcomas with more than 50% risk of metastatic disease, and 26 of 29 patients with follow-up had metastases or died of disease. An average survival time among pre-imatinib patients, who died of the disease was 33.4 months. Based on these findings, we conclude that presence of homozygous KIT exon 11 mutations is associated with malignant course of disease and should be considered an adverse prognostic marker in GISTs.
Journal of Pediatric Hematology/Oncology, 2012
Mesenchymal chondrosarcoma (MC) is an infrequent, highly malignant neoplasm of the soft tissues a... more Mesenchymal chondrosarcoma (MC) is an infrequent, highly malignant neoplasm of the soft tissues and bone. It is very rare in the pediatric age group, especially in the intraspinal location. Only 24 cases have been reported to date. The authors present a case of a 14-year-old boy with an intraspinal MC who died of the disease 50 months from the initial diagnosis and after the third local recurrence. The patient was treated with a combination of chemotherapy, radiotherapy, and surgery. The authors review the clinical presentation, diagnostics, and the efficacy of treatment of pediatric patients with MC reported in the literature from 1978 to 2010.
International Journal of Radiation Oncology*Biology*Physics, 2010
Purpose: To assess the outcomes of radiotherapy, in terms of local control and treatment complica... more Purpose: To assess the outcomes of radiotherapy, in terms of local control and treatment complications, of advanced or difficult giant cell tumors of bone (GCTB) that could not be treated by surgery. Methods and Materials: Among 122 consecutive patients with confirmed GCTB from 1985 to 2007, 77 patients were treated by megavoltage radiotherapy because they were inappropriate candidates for surgery. We have performed analysis of all data in terms of progression-free survival (PFS) and treatment morbidity. Median follow-up time was 58 months. Results: In the irradiated group, maximal tumor size ranged from 5 to 18 cm (median, 8.5). Anatomic distribution was as follows: femur, 27 cases; tibia, 19; radial/ulnar bone, 12; sacrum, 9; pelvic bones, 5; other, 5. Twenty-one patients (27%) were referred for local recurrence after $1 other treatment procedures. The radiation doses ranged from 26 to 89 Gy (median, 56; administered 1.8-2.0 Gy/fraction with average total duration of treatment of 5-7 weeks); 8 patients (10%) received <50 Gy. All patients tolerated treatment well without acute or late complications. All patients except two are alive. Local control was achieved in 65 patients (84%; bone recalcification/restitution of joint functions), 12 patients showed signs of local progression, all within irradiated fields (9 were treated successfully with salvage surgery). Five-and 10-year local PFS were 83% and 73%, respectively. Three patients developed lungs metastases. Malignant transformation of GCTB occurred in two patients. Conclusions: GCTB can be safely and effectively treated with megavoltage radiotherapy with local control rate >80% at 5 years. Our study confirms that radiotherapy of GCTB offers an alternative to difficult or complex surgery and may be an option of choice in the treatment of inoperable patients.
International Journal of Gynecological Cancer, 2010
Vulvar cancer is a rare condition representing about 4% of all female genital tract tumors. In co... more Vulvar cancer is a rare condition representing about 4% of all female genital tract tumors. In contrast to the established relationship of virtually all cervical cancer cases with the human papillomavirus (HPV) infection, the reported HPV positivity in vulvar carcinoma ranges widely. Using the Linear Array HPV Genotyping Test, we investigated the HPV incidence in a group of 46 Polish patients with vulvar squamous cell carcinoma (age range, 37-93 years; median age, 70.2 years) in clinical stages T1-2, N0-2, and M0. The presence of HPV DNA was confirmed in 7 of 46 (15%) primary tumor samples. HPV 16 was found in 5 tumors (71%). HPVs 6 and 58 were detected in the remaining 2 cases of virus-associated tumors. We conclude that a fraction of cancers of vulva associated with HPV is insignificant, given the HPV prevalence of 8.6% in the Polish population aged 55 to 59 years (the oldest cohort of Polish women studied to date).
Clinical Orthopaedics and Related Research®, 2012
Background The 5-year survival rates for localized liposarcomas reportedly vary from 75% to 91% w... more Background The 5-year survival rates for localized liposarcomas reportedly vary from 75% to 91% with histologic grade as the most important prognostic factor. However, it is unclear which other factors, including the initial surgery quality and recurrent tumors, influence survival in localized liposarcomas (LPS). Questions/Purposes We analyzed factors (including AJCC staging system) influencing survival and local control of resectable LPS of the extremities/trunk wall and the impact of surgery quality and tumor status and type of disease recurrences according to pathological subtype. Methods We retrospectively reviewed 181 patients with localized LPS: 110 were treated for primary tumors, 50 for recurrent tumors, and 21 for wide scar resection after unplanned nonradical resection. We determined survival rates and examined factors influencing survival. The minimum followup was 4 months (median, 52 months; range, 4-168 months). Results Five-year disease-specific (DSS), disease-free (DFS), and local relapse-free survival (LRFS) rates were: 80%, 58%, and 75%, respectively. Five-year local relapsefree survival rates for primary versus clinically recurrent tumor versus scar after nonradical resection were: 86.1%, 52.1%, and 73.3%, respectively. The following were independent negative prognostic factors for DSS (AJCC Stage C IIb), DFS (Grade 3; clinical recurrence; skin infiltration), and LRFS (clinical recurrence; R1 resection). An unplanned excision, although influencing local relapse-free survival, had no impact on disease-specific survival (calculated from date of first excision 5-year rate of 80%, considering impact of combined treatment of clinical recurrence/scar). Conclusions We confirmed the value of AJCC staging for predicting disease-specific survival in extremity/trunk wall LPS. Radical reresection of scar after nonradical primary tumor resection (+ radiotherapy) seems to improve Each author certifies that he or she, or a member of their immediate family, has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.
Cancer, 2011
BACKGROUND: The objectives of the current study were to assess the reliability of the new revisio... more BACKGROUND: The objectives of the current study were to assess the reliability of the new revision of the American Joint Committee on Cancer (AJCC) staging system for gastrointestinal stromal tumors (GISTs) based on the National Comprehensive Cancer Network-Armed Forces Institute of Pathology risk classification and to analyze the factors that influence after resection for primary GISTs in 2 AJCC groups: patients with GISTs originating from the stomach and omentum (G-GISTs) and patients with other primary GISTs located mainly in the small bowel (nongastric GISTs [NG-GISTs]). METHODS: The authors prospectively analyzed a group of 640 patients with primary, CD117-positive GISTs who underwent surgery with curative intention (R0/R1 resection), including 340 G-GISTs (55.5%) and 300 NG-GISTs (44.5%). Factors were explored that had an effect on disease-free survival time (DFS), which was calculated from the date of radical operation to the date of recurrence or last follow-up. The median follow-up was 39 months. RESULTS: Compared with NG-GISTs, G-GISTs were characterized by a significantly lower median size (5.3 cm and 8.5 cm, respectively; P < .0001) and lower mitotic activity (median, 3 in 50 high-power fields [HPF] vs 5 in 50 HPF; P < .0001), and they were diagnosed in older patients (median age, 62 years vs 57 years; P ¼ .002). The most commonly detected mutations in G-GIST were those located in KIT exon 11 (60.5%) and platelet-derived growth factor receptor alpha (PDGFRA) exon 18 (19%) versus KIT exons 11 and 9 in NG-GISTs (72% and 17.4%, respectively). The prognosis of patients who had G-GISTs was significantly better compared that of patients who had NG-GISTs, with 5-year DFS rates of 69% (median, 83 months) versus 43% (median, 33 months), respectively (P < .00001). The most significant prognostic factors that correlated with shorter DFS in both G-GISTs and NG-GISTs were primary tumor size >5 cm and >10 cm (P < .0001) and mitotic index >5 in 50 HPF and >10 in 50 HPF (P < .0001). The 5-year DFS rates in G-GISTs according to AJCC stage categories were as follows: 96% for stage IA tumors, 92% for stage IB tumors, 51% for II tumors, 22% for stage IIIA tumors, and 22% for stage IIIB tumors (P < .0001). The 5-year DFS rates in NG-GISTs according to AJCC categories were as follows: 92% for stage I tumors, 66% for stage II tumors, 28% for IIIA tumors, and 16% for IIIB tumors (P < .0001). The high prognostic significance of the AJCC classification also was confirmed for overall survival data, including the impact of therapy with tyrosine kinase inhibitors. CONCLUSIONS: The reliability of AJCC risk classification after resection of primary GIST was confirmed for DFS and overall survival. Patients with primary G-GISTs had a better prognosis than patients with NG-GISTs. In both groups, primary tumor size and mitotic activity were the most important prognostic factors in terms of DFS.
American Journal of Surgical Pathology, 2010
Cellular angiofibroma is a mesenchymal neoplasm that is characterized by a bland spindle cell com... more Cellular angiofibroma is a mesenchymal neoplasm that is characterized by a bland spindle cell component, morphologically reminiscent of spindle cell lipoma, and thick-walled vessels. The tumor occurs equally in men and women and usually arises in the inguino-scrotal or vulvovaginal regions. An earlier study of 51 cases from our group showed that the tumor follows a benign course without any tendency for recurrence. In 1 case, an intralesional microscopic nodule of pleomorphic liposarcoma was observed. The biologic significance of atypia or sarcomatous transformation in cellular angiofibroma remains uncertain. In this study, we characterized clinicopathologic features in 13 cases of cellular angiofibroma with morphologic atypia or sarcomatous transformation. Thirteen cases with atypia or sarcomatous transformation among 154 usual cellular angiofibromas identified between 1993 and 2009 were retrieved from consultation files. There were 12 females and 1 male ranging in age from 39 to 71 years (median age, 46 y). Tumor size ranged from 1.2 to 7.5 cm. In 11 cases, the tumors occurred in the vulva. One case each occurred in the paratesticular and hip regions. Most tumors were located in subcutaneous tissue. There were 4 cases of cellular angiofibroma with atypia. Three showed severely atypical cells as scattered foci within the cellular angiofibroma. One case showed a discrete nodule of atypical cells. There were 9 cases of cellular angiofibroma with morphologic features of sarcomatous transformation. In each case, abrupt transition to a discrete sarcomatous component was seen. Of these 9 cases, the sarcomatous component in 2 cases showed features of pleomorphic liposarcoma with multivacuolated lipoblasts readily identified. Three of these 9 cases showed discrete nodule(s) closely resembling atypical lipomatous tumor within usual cellular angiofibroma. In the remaining 4 cases, the sarcomatous component was composed of pleomorphic spindle cells arranged in various patterns. By immunohistochemistry, atypical cells and sarcomatous areas showed either multifocal or more diffuse p16 expression compared with either scattered or negative expression in the conventional cellular angiofibroma. The 3 cases with atypical lipomatous tumor-like areas were negative for MDM-2 and CDK4. Follow-up information was available for 7 patients (range from 2 to 75 mo; median: 14 mo). Six patients did not develop recurrence or metastasis. One patient died of metastatic carcinoma of unknown primary site 27 months after the diagnosis of cellular angiofibroma with sarcomatous transformation. Cellular angiofibroma with atypia or morphologic sarcomatous transformation occurs predominantly in the subcutaneous tissue of the vulva and, as yet, shows no evident tendency to recur based on limited clinical follow-up available for 7 cases. The sarcomatous component can show variable features including atypical lipomatous tumor, pleomorphic liposarcoma, and pleomorphic sarcoma NOS. Overexpression of p16 in the atypical cells and sarcomatous component suggests a possible underlying molecular mechanism.
The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Ewing... more The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Ewing sarcoma (ES) is a group of highly aggressive small round cell tumors of bone or soft tissue with high metastatic potential and low cure rate. ES tumors are associated with a rapid osteolysis and necrosis. The currently accepted clinical prognostic parameters do not accurately predict survival of high-risk patients. Moreover, neither the subtype of EWS–FLI1/ERG in the tumor, nor the detection of fusion transcripts in the peripheral blood (PB) samples, has prognostic value in ES patients. We evaluated the prevalence of circulating tumor cells (CTCs) in 34 adult ES patients. Since CTCs were confirmed in only small subset of patients, we further explored the expression profiles of PB leukocytes using a panel of genes associated with immune system status and increased tumor invasive-
Journal of Clinical Oncology, 2012
10538 Background: EFTs are characterized by chromosomal translocations leading to formation of on... more 10538 Background: EFTs are characterized by chromosomal translocations leading to formation of oncogenic EWSR1-FLI1 fusion gene in 85-90% of cases. The aim of the study was to detect circulating tumor cells (CTCs) carrying EWSR1-FLI1 fusion transcript in peripheral blood and assess their added value to standard diagnostic procedures and utility as a prognostic marker in EFTs. Methods: 10mL of whole blood was collected from 35 untreated adult EFTs patients at the diagnosis (period: 2008-2011, median age 27 years) and 13 healthy controls. 13 patients presented metastatic disease (M1) at the diagnosis. Nested RT-PCR was applied in triplicate for the detection of EWSR1-FLI1 transcript. Blood specimen was regarded CTC-positive when at least 2 out of 3 nested RT-PCR assays were positive and results were confirmed by sequencing. FISH assay for EWSR1 rearrangement was performed on FFPE tumor tissue in 28 available cases. Median follow-up was 16 months. Results: EWSR1-FLI1 transcript was det...
Journal of Clinical Oncology, 2013
e22046 Background: EFTs are characterized by oncogenic EWSR1-FLI1 fusion gene, which can be detec... more e22046 Background: EFTs are characterized by oncogenic EWSR1-FLI1 fusion gene, which can be detected in 85-90% of tumors and in 20-70% of peripheral blood specimens. It has been previously reported that downregulation of CDH2 (encoding N-cadherin) and overexpression of CDT2 [also known as DTL, encoding denticleless homolog (Drosophila)]in EFTs tumors are associated with poor prognosis. The aim of the study was to evaluate the expression levels of these markers in the circulating tumor cells and assess their utility as prognostic markers in EFTs. Methods: 10mL of PB was collected from 24 untreated adult EFTs patients at the diagnosis (period: 2009-2011, median age 30 years). 9 blood specimens from healthy individuals, and 5 untreated frozen EFTs tumor samples were used as controls. 8 EFTs patients presented metastatic disease (M1) at the diagnosis and 5 patients died during the follow-up period. Median follow-up was 22 months. Quantitative reverse transcription PCR (qRT-PCR) for CDH2...
Onkologia W Praktyce Klinicznej, 2010
Zalecenia postępowania diagnostyczno-terapeutycznego u dorosłych chorych na pierwotne nowotwory z... more Zalecenia postępowania diagnostyczno-terapeutycznego u dorosłych chorych na pierwotne nowotwory złośliwe kości Recommendations for diagnostics and therapy of adult patients with malignant primary bone tumors STRESZCZENIE Mięsaki kości u dorosłych stanowią heterogenną grupę bardzo rzadkich nowotworów pochodzenia mezenchymalnego (poniżej 0,5% nowotworów złośliwych u dorosłych). Pod względem klinicznym mięsaki kości można podzielić na mięsaki wrzecionowatokomórkowe (obejmujące mięsaki kościopochodne, większość chrzęstniakomięsaków i inne rzadsze podtypy) oraz drobnokomórkowe (głównie rodzina mięsaków Ewinga). Prawidłowe rozpoznanie i skuteczne leczenie skojarzone pierwotnych nowotworów kości są sumą współpracy radiologów, chirurgów onkologów i chirurgów ortopedów, onkologów klinicznych, radioterapeutów, rehabilitantów, patologów, specjalistów medycyny nuklearnej i biologów molekularnych. Bezwzględnym warunkiem w diagnostyce i leczeniu pierwotnych nowotworów złośliwych kości jest wielodyscyplinarna współpraca wielospecjalistyczna w doświadczonych ośrodkach. Polepszenie diagnostyki mięsaków kości, wprowadzenie zasad terapii skojarzonej i postęp technologiczny spowodowały rozszerzenie wskazań do stosowania operacji oszczędzających kończynę oraz poprawiły odległe wyniki leczenia.
International journal of clinical and experimental pathology, 2015
The study compares detection rates of oncogenic BRAF mutations in a homogenous group of 236 FFPE ... more The study compares detection rates of oncogenic BRAF mutations in a homogenous group of 236 FFPE cutaneous melanoma lymph node metastases, collected in one cancer center. BRAF mutational status was verified by two independent in-house PCR/Sanger sequencing tests, and the Cobas® 4800 BRAF V600 Mutation Test. The best of two sequencing approaches returned results for 230/236 samples. In 140 (60.9%), the mutation in codon 600 of BRAF was found. 91.4% of all mutated cases (128 samples) represented p.V600E. Both Sanger-based tests gave reproducible results although they differed significantly in the percentage of amplifiable samples: 230/236 to 109/143. Cobas generated results in all 236 cases, mutations changing codon V600 were detected in 144 of them (61.0%), including 5 not amplifiable and 5 negative in the standard sequencing. However, 6 cases positive in sequencing turned out to be negative in Cobas. Both tests provided us with the same BRAF V600 mutational status in 219 out of 230 ...
Polish journal of pathology : official journal of the Polish Society of Pathologists, 2009
Synovial sarcoma (SyS) occurs mostly in young adults and is characterized by an aggressive course... more Synovial sarcoma (SyS) occurs mostly in young adults and is characterized by an aggressive course. Combined treatment including chemotherapy, radiotherapy and surgical excision of the tumour is still not satisfactory, with mean 5-year survival of 30-50%. New targeted treatment options have appeared recently, e.g. HER2 and EGFR antagonists. Initial studies have revealed immunohistochemical overexpression of the EGFR in SyS; therefore trials with EGFR antagonist therapy have commenced. The aim of our study was to evaluate the status of HER2, EGFR and TOPIIA in SyS before and after combined therapy. Immunohistochemistry and FISH tests were performed. Significant discrepancies between protein expression and gene status were found. The authors discuss the potential reasons for that phenomenon.
European journal of dermatology : EJD, 2013
ejd.2013.1992 Auteur(s) : Katarzyna Wiater1 wiater.katarzyna@gmail.com, Marcin Zdzienicki1, Tadeu... more ejd.2013.1992 Auteur(s) : Katarzyna Wiater1 wiater.katarzyna@gmail.com, Marcin Zdzienicki1, Tadeusz Morysinski1, Hanna Kosela1, Anna Klimczak1, Mariusz Obrebski2, Konrad Ptaszynski3, Piotr Rutkowski1 1 Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie Memorial Cancer Center, Roentgena Str. 5, 02-781 Warsaw, Poland 2 Department of Surgery, Regional Hospital Plock, Poland 3 Department of Pathology, The Medical Center of Postgraduate Education, Warsaw, Poland In April [...]
Polish journal of pathology : official journal of the Polish Society of Pathologists, 2009
Small round cell tumours (SRCT) of bone and soft tissue constitute a heterogeneous group of neopl... more Small round cell tumours (SRCT) of bone and soft tissue constitute a heterogeneous group of neoplasms with similar histological and cytological features. Immunohistochemical studies with panels of antibodies are necessary in order to make the diagnosis. A molecular testing is helpful in many cases. To assess the value of IHC and FISH tests in the differential diagnosis of SRCT. The material was obtained from patients diagnosed and treated at the Maria Skłodowska-Curie Memorial Cancer Center-Institute in Warsaw between February 2003 and March 2009. One hundred and thirty one patients with the initial diagnosis of SRCT of bone or soft tissue were qualified to the investigation. The material from the primary tumour was obtained by an open or core biopsy in all the patients. During the treatment the patients were monitored, the local recurrence and the distant metastases were reported. The IHC study was performed routinely using wide panels of antibodies. FISH tests: EWSR1, SS18 (SYT), ...
Przegla̧d lekarski, 2003
Neuroblastoma is the third most common neoplasm of childhood. About 70% of cases occurs by 5 year... more Neuroblastoma is the third most common neoplasm of childhood. About 70% of cases occurs by 5 years old and around 95% cases in the patients younger than 10 years old. Neuroblastoma is part of the spectrum of the family neuroblastic tumors. The family consists of heterogeneous group of tumors, difficult to classify. Additionally some cases of neuroblastoma show tendency to self-maturation and regression. The family consists of neuroblastoma (NB), ganglio-neuroblastoma (GNB) and ganglineuroma (GN). In recent years there has been considerable development in the classification concepts from purely histological to clinico-pathological one. These schemes include clinical, pathological and molecular features od tumors which allow more accurate prognostication.
Zeszyty Naukowe WCO, Letters in Oncology Science, 2013
Tumor Biology, 2010
Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous cell epithelia and in squa... more Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous cell epithelia and in squamous cell carcinomas (SCC). Two nearly identical genes encode the inhibitory serpins SCCA1 (SERPINB3) and SCCA2 (SERPINB4). Serum levels of SCCA are elevated in patients with benign skin diseases and in patients with SCC. SCCA, used for the monitoring of SCC patients, presents no satisfactory diagnostic specificity. As we have shown previously, the reverse transcription polymerase chain reaction (RT-PCR)-based SCCA messenger RNA (mRNA) testing aimed at detecting disseminated cancer cells may be hampered by the false-positive results due to SCCA expression in activated peripheral blood mononuclear cells (PBMC). The aim of this study was to assess the expression of SCCA at mRNA and protein levels in cultured normal PBMC, compared to that in vulvar SCC (VSCC) samples. High SCCA concentrations were found in vulvar tumours and in metastatic lymph nodes, while negative inguinal lymph nodes from the same patients often presented significantly less SCCA. In normal activated PBMC, the level of SCCA protein was the lowest. At the mRNA level SCCA was detectable in normal PBMC even in cultures with no mitogen stimulation, but only by the nested RT-PCR, contrary to VSCC samples found to be SCCA positive already in one-step PCR. Both SCCA1 and SCCA2 transcripts were present in cultured PBMC; SCCA1 was expressed at a higher level than SCCA2. In conclusion, both SCCA forms are detectable in normal
Laboratory Investigation, 2006
In this paper, we present whole-organ histologic and genetic mapping studies using hypervariable ... more In this paper, we present whole-organ histologic and genetic mapping studies using hypervariable DNA markers on chromosome 13 and then integrate the recombination-and single-nucleotide polymorphic sites (SNPs)-based deletion maps with the annotated genome sequence. Using bladders resected from patients with invasive urothelial carcinoma, we studied allelic patterns of 40 microsatellite markers mapping to all regions of chromosome 13 and 79 SNPs located within the 13q14 region containing the RB1 gene. A whole-organ histologic and genetic mapping strategy was used to identify the evolution of allelic losses on chromosome 13 during the progression of bladder neoplasia. Markers mapping to chromosomal regions involved in clonal expansion of preneoplastic intraurothelial lesions were subsequently tested in 25 tumors and 21 voided urine samples of patients with bladder cancer. Four clusters of allelic losses mapping to distinct regions of chromosome 13 were identified. Markers mapping to the 13q14 region that is flanked by D13S263 and D13S276, which contains the RB1 gene, showed allelic losses associated with early clonal expansion of intraurothelial neoplasia. Such losses could be identified in approximately 32% bladder tumor tissue samples and 38% of voided urines from patients with bladder cancer. The integration of distribution patterns of clonal allelic losses revealed by the microsatellite markers with those obtained by genotyping of SNPs disclosed that the loss within an approximately 4-Mb segment centered around RB1 may represent an incipient event in bladder neoplasia. However, the inactivation of RB1 occurred later and was associated with the onset of severe dysplasia/ carcinoma in situ. Our studies provide evidence for the presence of critical alternative candidate genes mapping to the 13q14 region that are involved in clonal expansion of neoplasia within the bladder antecedent to the inactivation of the RB1 gene.
Laboratory Investigation, 2007
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestina... more Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestinal tract. GISTs range from benign indolent neoplasms to highly malignant sarcomas. Gain-of-function mutations of tyrosine kinase receptors, KIT or PDGFRA, have been identified in most GISTs. In this study, we report 36 GIST patients whose tumors had homozygous KIT exon 11 mutations detected by direct sequencing of PCR products. Loss of heterozygosity in KIT locus and other chromosome 4 loci were documented in majority of these tumors. However, fluorescence in situ hybridization with KIT locus-specific probe and chromosome 4 centromeric enumeration probe showed no evidence of KIT hemizygosity in a majority of analyzed cases. These findings are consistent with duplication of chromosome 4 with KIT mutant allele. Homozygous KIT exon 11 mutations were found in 33 primary tumors and 7 metastatic lesions. In two cases, shift from heterozygosity to homozygosity was documented during tumor progression being present in metastases, but not in primary tumors. Among primary GISTs, there were 16 gastric, 18 intestinal and 2 from unknown locations. An average primary tumor size was 12 cm and average mitotic activity 32/50 HPFs. Out of 32 tumors 29 (90.6%) with complete clinicopathologic data were diagnosed as sarcomas with more than 50% risk of metastatic disease, and 26 of 29 patients with follow-up had metastases or died of disease. An average survival time among pre-imatinib patients, who died of the disease was 33.4 months. Based on these findings, we conclude that presence of homozygous KIT exon 11 mutations is associated with malignant course of disease and should be considered an adverse prognostic marker in GISTs.
Journal of Pediatric Hematology/Oncology, 2012
Mesenchymal chondrosarcoma (MC) is an infrequent, highly malignant neoplasm of the soft tissues a... more Mesenchymal chondrosarcoma (MC) is an infrequent, highly malignant neoplasm of the soft tissues and bone. It is very rare in the pediatric age group, especially in the intraspinal location. Only 24 cases have been reported to date. The authors present a case of a 14-year-old boy with an intraspinal MC who died of the disease 50 months from the initial diagnosis and after the third local recurrence. The patient was treated with a combination of chemotherapy, radiotherapy, and surgery. The authors review the clinical presentation, diagnostics, and the efficacy of treatment of pediatric patients with MC reported in the literature from 1978 to 2010.
International Journal of Radiation Oncology*Biology*Physics, 2010
Purpose: To assess the outcomes of radiotherapy, in terms of local control and treatment complica... more Purpose: To assess the outcomes of radiotherapy, in terms of local control and treatment complications, of advanced or difficult giant cell tumors of bone (GCTB) that could not be treated by surgery. Methods and Materials: Among 122 consecutive patients with confirmed GCTB from 1985 to 2007, 77 patients were treated by megavoltage radiotherapy because they were inappropriate candidates for surgery. We have performed analysis of all data in terms of progression-free survival (PFS) and treatment morbidity. Median follow-up time was 58 months. Results: In the irradiated group, maximal tumor size ranged from 5 to 18 cm (median, 8.5). Anatomic distribution was as follows: femur, 27 cases; tibia, 19; radial/ulnar bone, 12; sacrum, 9; pelvic bones, 5; other, 5. Twenty-one patients (27%) were referred for local recurrence after $1 other treatment procedures. The radiation doses ranged from 26 to 89 Gy (median, 56; administered 1.8-2.0 Gy/fraction with average total duration of treatment of 5-7 weeks); 8 patients (10%) received <50 Gy. All patients tolerated treatment well without acute or late complications. All patients except two are alive. Local control was achieved in 65 patients (84%; bone recalcification/restitution of joint functions), 12 patients showed signs of local progression, all within irradiated fields (9 were treated successfully with salvage surgery). Five-and 10-year local PFS were 83% and 73%, respectively. Three patients developed lungs metastases. Malignant transformation of GCTB occurred in two patients. Conclusions: GCTB can be safely and effectively treated with megavoltage radiotherapy with local control rate >80% at 5 years. Our study confirms that radiotherapy of GCTB offers an alternative to difficult or complex surgery and may be an option of choice in the treatment of inoperable patients.
International Journal of Gynecological Cancer, 2010
Vulvar cancer is a rare condition representing about 4% of all female genital tract tumors. In co... more Vulvar cancer is a rare condition representing about 4% of all female genital tract tumors. In contrast to the established relationship of virtually all cervical cancer cases with the human papillomavirus (HPV) infection, the reported HPV positivity in vulvar carcinoma ranges widely. Using the Linear Array HPV Genotyping Test, we investigated the HPV incidence in a group of 46 Polish patients with vulvar squamous cell carcinoma (age range, 37-93 years; median age, 70.2 years) in clinical stages T1-2, N0-2, and M0. The presence of HPV DNA was confirmed in 7 of 46 (15%) primary tumor samples. HPV 16 was found in 5 tumors (71%). HPVs 6 and 58 were detected in the remaining 2 cases of virus-associated tumors. We conclude that a fraction of cancers of vulva associated with HPV is insignificant, given the HPV prevalence of 8.6% in the Polish population aged 55 to 59 years (the oldest cohort of Polish women studied to date).
Clinical Orthopaedics and Related Research®, 2012
Background The 5-year survival rates for localized liposarcomas reportedly vary from 75% to 91% w... more Background The 5-year survival rates for localized liposarcomas reportedly vary from 75% to 91% with histologic grade as the most important prognostic factor. However, it is unclear which other factors, including the initial surgery quality and recurrent tumors, influence survival in localized liposarcomas (LPS). Questions/Purposes We analyzed factors (including AJCC staging system) influencing survival and local control of resectable LPS of the extremities/trunk wall and the impact of surgery quality and tumor status and type of disease recurrences according to pathological subtype. Methods We retrospectively reviewed 181 patients with localized LPS: 110 were treated for primary tumors, 50 for recurrent tumors, and 21 for wide scar resection after unplanned nonradical resection. We determined survival rates and examined factors influencing survival. The minimum followup was 4 months (median, 52 months; range, 4-168 months). Results Five-year disease-specific (DSS), disease-free (DFS), and local relapse-free survival (LRFS) rates were: 80%, 58%, and 75%, respectively. Five-year local relapsefree survival rates for primary versus clinically recurrent tumor versus scar after nonradical resection were: 86.1%, 52.1%, and 73.3%, respectively. The following were independent negative prognostic factors for DSS (AJCC Stage C IIb), DFS (Grade 3; clinical recurrence; skin infiltration), and LRFS (clinical recurrence; R1 resection). An unplanned excision, although influencing local relapse-free survival, had no impact on disease-specific survival (calculated from date of first excision 5-year rate of 80%, considering impact of combined treatment of clinical recurrence/scar). Conclusions We confirmed the value of AJCC staging for predicting disease-specific survival in extremity/trunk wall LPS. Radical reresection of scar after nonradical primary tumor resection (+ radiotherapy) seems to improve Each author certifies that he or she, or a member of their immediate family, has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.
Cancer, 2011
BACKGROUND: The objectives of the current study were to assess the reliability of the new revisio... more BACKGROUND: The objectives of the current study were to assess the reliability of the new revision of the American Joint Committee on Cancer (AJCC) staging system for gastrointestinal stromal tumors (GISTs) based on the National Comprehensive Cancer Network-Armed Forces Institute of Pathology risk classification and to analyze the factors that influence after resection for primary GISTs in 2 AJCC groups: patients with GISTs originating from the stomach and omentum (G-GISTs) and patients with other primary GISTs located mainly in the small bowel (nongastric GISTs [NG-GISTs]). METHODS: The authors prospectively analyzed a group of 640 patients with primary, CD117-positive GISTs who underwent surgery with curative intention (R0/R1 resection), including 340 G-GISTs (55.5%) and 300 NG-GISTs (44.5%). Factors were explored that had an effect on disease-free survival time (DFS), which was calculated from the date of radical operation to the date of recurrence or last follow-up. The median follow-up was 39 months. RESULTS: Compared with NG-GISTs, G-GISTs were characterized by a significantly lower median size (5.3 cm and 8.5 cm, respectively; P < .0001) and lower mitotic activity (median, 3 in 50 high-power fields [HPF] vs 5 in 50 HPF; P < .0001), and they were diagnosed in older patients (median age, 62 years vs 57 years; P ¼ .002). The most commonly detected mutations in G-GIST were those located in KIT exon 11 (60.5%) and platelet-derived growth factor receptor alpha (PDGFRA) exon 18 (19%) versus KIT exons 11 and 9 in NG-GISTs (72% and 17.4%, respectively). The prognosis of patients who had G-GISTs was significantly better compared that of patients who had NG-GISTs, with 5-year DFS rates of 69% (median, 83 months) versus 43% (median, 33 months), respectively (P < .00001). The most significant prognostic factors that correlated with shorter DFS in both G-GISTs and NG-GISTs were primary tumor size >5 cm and >10 cm (P < .0001) and mitotic index >5 in 50 HPF and >10 in 50 HPF (P < .0001). The 5-year DFS rates in G-GISTs according to AJCC stage categories were as follows: 96% for stage IA tumors, 92% for stage IB tumors, 51% for II tumors, 22% for stage IIIA tumors, and 22% for stage IIIB tumors (P < .0001). The 5-year DFS rates in NG-GISTs according to AJCC categories were as follows: 92% for stage I tumors, 66% for stage II tumors, 28% for IIIA tumors, and 16% for IIIB tumors (P < .0001). The high prognostic significance of the AJCC classification also was confirmed for overall survival data, including the impact of therapy with tyrosine kinase inhibitors. CONCLUSIONS: The reliability of AJCC risk classification after resection of primary GIST was confirmed for DFS and overall survival. Patients with primary G-GISTs had a better prognosis than patients with NG-GISTs. In both groups, primary tumor size and mitotic activity were the most important prognostic factors in terms of DFS.