Metin Keskin - Academia.edu (original) (raw)

Papers by Metin Keskin

İstanbul Tıp Fakültesi Dergisi, 2020

Background: The role of radiotherapy in the adjuvant treatment of gastric cancer (GC) remains to ... more Background: The role of radiotherapy in the adjuvant treatment of gastric cancer (GC) remains to be elucidated. This study aimed to assess the additional benefit of radiotherapy in the adjuvant treatment of GC. Methods: In this retrospective cohort study, we included 230 gastric adenocarcinoma patients who underwent D2 dissection between January 2004 and December 2019. Patients without R0 resection, who underwent metastasectomy at surgery, and treated with the neoadjuvant treatment were excluded. The co-primary endpoints were overall survival (OS) and disease-free survival (DFS). The secondary endpoints were the locoregional and distant metastasis risk and adverse events (AEs) leading to treatment discontinuation. Results: One hundred and sixty-six and 64 patients were included in the chemoradiotherapy (CRT) and chemotherapy (ChT) arms, respectively. The median OS was 135.8 months [interquartile range (IQR): 99.4–172.2] and 97 months (IQR: 59.7–134.3) in the CRT and the ChT arms, re...

Medicine, 2021

Abstract Surgical resection is an unavoidable part of the current treatment options for Crohn&#39... more Abstract Surgical resection is an unavoidable part of the current treatment options for Crohn's disease (CD), and more than half of patients develop recurrence. The aim of this study was to investigate the predictors for recurrence in the long-term follow-up of CD patients after surgery. Medical records of consecutive CD patients who were operated on between January 2003 and January 2015 were retrospectively analyzed. Data including demographic and clinical characteristics of the patients were recorded. Recurrence was evaluated based on the Crohn's Disease Activity Index or endoscopic findings. The majority of 112 patients were males (n = 64, 57.1%), and 61 (54.4%) of them were active smokers. The median follow-up was 113 (range: 61–197) months. Disease recurrence occurred in 16 (14.3%) patients at a median of 13.5 months. The endoscopic recurrence rate was 8% (n = 9) at 1 year, 12.5% (n = 14) at 5 years, and 13.4% (n = 15) at 10 years. One (0.9%) patient underwent colonoscopic balloon dilatation at 1 year, and 7 (6.3%) patients needed re-resection at a median of 36 months. The age of the patient at the time of diagnosis (P = .033), penetrating disease behavior (P = .011), intra-abdominal abscess (P = 0.040) and, concomitant fistula and intra-abdominal abscess (P = .017) were associated with disease recurrence. Our study results suggest that the patients’ age at the time of diagnosis, penetrating disease, intra-abdominal abscess, and concomitant fistula and abscess are the risk factors for CD recurrence after surgery.

International Surgery, 2021

Background Crohn's disease needs a multidisciplinary approach, and surgery will ultimately be... more Background Crohn's disease needs a multidisciplinary approach, and surgery will ultimately be necessary for most patients. Complications usually occur after surgery. Objective This study aims to present complication rates in surgically treated Crohn's disease patients at a single institution and to determine possible risk factors. Methods A retrospective analysis of 112 consecutive surgery performed on Crohn's disease patients between 2003 and 2015. The demographic data, patient and disease characteristics, surgery type, and complications were analyzed. Results Of 112 patients, 64 (57.1%) were male and 48 (42.9%) were female. The mean age was 34 (range, 18–78) years. The mean follow-up was 114 ± 32.4 (range, 61–197) months. The most common early complications were intra-abdominal abscess formation (n = 10, 8.9%) and wound infection (n = 7, 6.26%). The incisional hernia was the most common late complication (n = 4, 3.6%). Nonmodifiable disease features associated with com...

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2021

BACKGROUND The true incidence of contralateral occult inguinal hernia (OIH) is a debate. The repa... more BACKGROUND The true incidence of contralateral occult inguinal hernia (OIH) is a debate. The repair of contralateral OIH in the treatment context of clinical symptomatic unilateral inguinal hernia (IH) is controversial. This study aimed to assess the effect and clinical benefit of preoperative ultrasound (US) in the diagnosis of contralateral OIH performed before surgery. METHODS The retrospective data of 155 consecutive male patients who underwent IH repair between January 2014 and January 2020 were analyzed. The surgical procedures for IH and the clinical outcomes of the US were evaluated. RESULTS Of 155 patients, 29 (18.7%) presented with bilateral IH. Preoperative US was performed in 73 cases of clinical unilateral IH (n=126), and 30 (23.8%) patients were found to have a contralateral OIH. The totally extrapreperitoneal (TEP) or Lichtenstein repair was conducted. Bilateral IH repair was proposed for all, but only 28 agreed and underwent bilateral repair. Patients with clinically bilateral hernia had more complications compared with patients diagnosed to have occult contralateral IH after the US (n=3 vs. n=0). In the overall group, the TEP procedure resulted in shorter hospital stay (P=0.001) and less pain (P=0.021). CONCLUSIONS The preoperative US may be recommended to assess the presence of a contralateral OIH as it is a noninvasive, radiation-free, widely available, relatively cheap diagnostic method. The preoperative US may change the surgical approach in up to 1/4 patients with a clinical unilateral IH. Either Lichtenstein repair or TEP repair can be performed with an acceptable complication rate in the case of OIH.

Diseases of the Colon & Rectum, 2020

Background: Intracorporeal anastomosis is associated with several short-term benefits. However, i... more Background: Intracorporeal anastomosis is associated with several short-term benefits. However, it is a technically challenging procedure with potential risks. Objective: To investigate differences in short-term complications and long-term incisional hernia rates after robotic right colectomy with intracorporeal versus extracorporeal anastomoses and standardized extraction sites.

İstanbul Tıp Fakültesi Dergisi, 2019

Mide kanseri nedeniyle radikal cerrahi uygulanan olgular arasında erken evre mide kanseri sıklığı... more Mide kanseri nedeniyle radikal cerrahi uygulanan olgular arasında erken evre mide kanseri sıklığı ve bu olgularda postoperatif erken ve geç dönem sonuçlarının değerlendirilmesi amaçlanmıştır. Yöntem: Bu çalışmada 2006-2013 yılları arasında mide kanseri nedeniyle radikal cerrahi uygulanan 391 olgudan, histopatolojik değerlendirme sonucunda erken evre mide kanseri saptanan 39 olgunun demografik verileri, patolojik bulguları ve klinik sonuçları retrospektif olarak incelenmiştir. Bulgular: Morbidite 13 (%33) hastada izlenirken, mortalite görülmedi. İnvazyon derinliği olguların 26'sında (%67) submukozal, 13'ünde (%33) intramukozal idi. Hastaların 11'inde (%28) lenf nodu metastazı saptanmıştır. İntramukozal yerleşimli tümörlerde lenf nodu metastazı oranı %14'iken submukozal tümörlerde bu oran %34,6'ya çıkmaktaydı. Ortalama takip süreleri 73,6 ay (48-111 ay) idi. Uzun dönem takiplerinde 4 olguda (%10) hastalık nüksü saptanırken 3 olgu (%7,5) eks olmuştur. Olguların 35'i (%89,7) hastalıksız olarak takip edilmektedir. Sonuç: Uzak Doğu Ülkelerine kıyasla, çalışmamızda erken evre mide kanseri prevelansı daha düşük olarak bulunmuştur. Bununla birlikte, erken evre mide kanserinde lenf nodu tutulumunun daha yüksek olduğu saptanmıştır. Japon Endoskopik Tedavi Kılavuzuna göre hastaların sadece %1,8'i endoskopik rezeksiyona uygun bulunmuştur. Bu veriler doğrultusunda, ülkemizde radikal cerrahinin erken evre mide kanseri için en uygun tedavi seçeneği olduğunu düşünüyoruz.

Turkish Journal of Biochemistry, 2019

Aim ATM, RAD51 and TP73 are genes that take part in DNA repair pathways. The aim of this prospect... more Aim ATM, RAD51 and TP73 are genes that take part in DNA repair pathways. The aim of this prospective case-control study was to determine the genotype and allele distributions of the ATM 5′-UTR G/A, RAD51 135 G/C and TP73 GC/AT polymorphisms and their relationship with clinical parameters in Turkish colorectal cancer (CRC) patients. Material and methods One hundred and four CRC patients and 113 healthy individuals were included in this study as control. The polymerase chain reaction-restriction fragment length polymorphism techniques were used. Results The ATM 5′-UTR G/A polymorphism GG (p = 0.001) and AA (p = 0.0001) genotypes were found higher in the patient group, while the GA genotype (p = 0.0001) and A allele (p = 0.001) were significantly higher in the control group. Moreover, the GG genotype (p = 0.042) was higher among patients with advanced-stage cancer and, while GA genotype (p = 0.047) was increased in patients without perineural invasion. The RAD51 135 G/C polymorphism GC...

European Journal of Gastroenterology & Hepatology, 2019

Objectives Isoniazid (INH) prophylaxis is recommended for the prevention of tuberculosis (TB) rea... more Objectives Isoniazid (INH) prophylaxis is recommended for the prevention of tuberculosis (TB) reactivation before or/and during initiation of treatment with tumour necrosis factor antagonists (anti-TNF agents). Nonetheless, the long-term effectiveness of chemoprophylaxis is not clear. In this study, we aimed to evaluate the characteristics of patients who developed TB reactivation in spite of INH prophylaxis associated with anti-TNF treatment. Patients and methods In this retrospective study, medical records of 1263 patients with inflammatory bowel disease were reviewed. Baseline TB screening tests (purified protein derivative test and/or QuantiFERON-TB Gold test) were performed on all patients before initiation of anti-TNF therapy. Patients with purified protein derivative of more than 5 mm and/or a positive result of the QuantiFERON-TB Gold test received INH prophylaxis for 9 months. We analysed the data of patients diagnosed with TB reactivation during the anti-TNF treatment despite INH chemoprophylaxis. Results Overall, 175 patients underwent anti-TNF treatment. Sixty of these 175 patients had pretreatment testing showing latent TB infection and therefore were treated concomitantly with INH for 9 months in addition to their anti-TNF treatment. TB reactivation occurred in four of these 60 co-INH/anti-TNF treated patients. Active TB was diagnosed after 37.5±27 (range: 18–84) months of anti-TNF treatment. In two of the four patients that active TB was diagnosed, was also detected other Mycobacterium spp.: M. bovis in one patient and M. genavense in the other one. Conclusion INH chemoprophylaxis may not prevent the reactivation of TB during anti-TNF therapy in the long-term. Patients should be carefully and periodically screened for TB reactivation during anti-TNF therapy.

Journal of Gastrointestinal Surgery, 2019

Background-Pathologic complete response (pCR) is associated with better prognosis and guides mana... more Background-Pathologic complete response (pCR) is associated with better prognosis and guides management for patients with advanced rectal cancer. Response rates vary between series for unclear reasons. We examine whether the thoroughness of pathologic assessment explains differences in pCR rates. Methods-We retrospectively reviewed pathology reports from patients with stage II/III rectal cancer who underwent chemoradiation and resection in a prospective, multicenter trial. We utilized a novel measure for the thoroughness of pathologic assessment by dividing residual tumor size by the number of cassettes evaluated (tumor size to cassette ratio, TSCR), and evaluated whether TSCR is associated with pCR. We validated our findings using a separate cohort. Results-From the trial cohort, 71 of 247 (29%) patients achieved pCR. The pCR rate ranged from 0 to 45% and mean TSCR ranged 0.29 to 0.87 across 12 institutions. Within each institution, a lower TSCR was associated with pCR, demonstrating a higher degree of thoroughness used for tumors that achieved pCR. Moreover, across all samples, low TSCR was independently associated with pCR on multivariable analysis. This finding was corroborated in a separate cohort of 201 tumors evaluated by five pathologists; each pathologist had a lower mean TSCR for pCR calls compared with non-pCR calls. However, the mean TSCR for an institution was not associated with its overall pCR rate. Conclusions-Pathologists assess rectal cancers that have responded significantly to neoadjuvant therapy more thoroughly. Thoroughness does not appear to explain differences in pCR rates between institutions. Our results suggest pCR is not a sampling artifact.

Human Reproduction, 1999

Introduction: Recent investigations have indicated that genital infections could be one of the re... more Introduction: Recent investigations have indicated that genital infections could be one of the reasons for miscarriage or premature labour in-patients after in-vitro fertilization (IVF). However, knowledge of possible negative effects of infection,

Erciyes Tıp Dergisi/Erciyes Medical Journal, 2017

Gastric foregut duplication cyst is a rare congenital disease. It is usually revealed with imagin... more Gastric foregut duplication cyst is a rare congenital disease. It is usually revealed with imaging study during the diagnosis of nonspecific symptoms, such as abdominal pain, nausea, and vomiting. Here we report the case of a male patient who underwent imaging study for the examination of a benign prostatic hyperplasia. A 3-cm mass containing cystic areas behind the gastric fundus was revealed on abdominal computed tomography. Laparoscopic gastric wedge resection was performed and the histopathological work-up of the specimen was reported as a foregut duplication cyst.

Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland, Jan 26, 2017

Studies have demonstrated a relationship between lymph node (LN) yield and survival after colecto... more Studies have demonstrated a relationship between lymph node (LN) yield and survival after colectomy for cancer. The impact of surgical technique on lymph node yield has not been well explored. This is a retrospective study of right colectomies (RC) for cancer at a single institution from 2012-2014. Exclusion criteria were previous colectomy, emergent and palliative operations. All data were collected by chart review. Primary outcomes were LN yield and the lymph node to length of surgical specimen (LN-LSS) ratio. Multivariable mixed models were created with surgeon and pathologist as random effects. Sensitivity analyses were performed to exclude stage IV cancers and to analyze groups on an "as-treated" basis. We identified 181 open (O-RC), 163 laparoscopic (L-RC) and 119 robotic (R-RC) cases. Open RC was more commonly performed in females with metastatic disease. Mean LN yield was 28, 29, and 34 in O-RC, L-RC, and R-RC, respectively; mean LN-LSS ratios were 0.83, 0.91 and 1...

Journal of cancer research and clinical oncology, Jan 3, 2017

Preoperative short-course radiotherapy (SCRT) followed by surgery has shown advantage over surger... more Preoperative short-course radiotherapy (SCRT) followed by surgery has shown advantage over surgery alone in patients with resectable rectal carcinoma (RC); however, the importance of the timing of surgery after SCRT has not been well defined. This study aimed to investigate the effect of this duration on treatment outcomes. Patients who underwent surgery after SCRT (25 Gy/500 cGy/daily/5fr, monday-friday) for resectable and infraperitoneal rectal adenocarcinoma (T3N0/(+)) were included into the study. Patients were divided into two groups in terms of the timing of surgery: delayed surgery (>4 weeks) or immediate surgery (<4 weeks). A hundred and thirty-six patients were included in the study. Median time between RT and surgery was 4 ± 5.7 (1-58) weeks, where 68% (n = 93) patients underwent delayed surgery (≥4 weeks). The two groups did not differ in terms of surgical margin positivity, pathological tumor regression, N downstaging, or T downstaging (p > 0.05 for all). Howeve...

Chirurgia (Bucharest, Romania : 1990)

Rectal prolapse (RP) is one of the benign anorectal diseases and impairs the quality of life due ... more Rectal prolapse (RP) is one of the benign anorectal diseases and impairs the quality of life due to co-existing constipation and incontinence problems. There is no consensus for the most accurate surgical method for its treatment. The objective was to evaluate the short- and long-term results of patients with rectal prolapse who underwent surgery in our clinic. A retrospective analysis was performed of 83 patients with RP who underwent surgery between 1997-2013 in terms of demographic data, surgical technique, complications, and early and late outcomes. The mean age was 45 years (± 18 years) and 60% (n = 50) of the patients were female. The mean body mass index (BMI) was 24.3 (± 4.1) kg/m2. The mean age was significantly higher in the transperineal approach (PA group) than transabdominal approach (TA group) (p < 0.05). The length of hospital stay was not affected by surgical technique (open or laparoscopic or perineal surgery), but in the subgroup analysis it was significantly sh...

Surgical laparoscopy, endoscopy & percutaneous techniques, 2016

We aimed to compare the short-term and long-term results of laparoscopic and open rectal resectio... more We aimed to compare the short-term and long-term results of laparoscopic and open rectal resections. A total of 587 rectal cancer patients were included. The main measures were demographic data, duration of surgery, early postoperative results, pathologic data, and long-term follow-up. There were no significant differences in demographic data, morbidity rate, tumor location, and sphincter-preservation rates between the 2 groups. The duration of surgery (155 vs. 173 min, P<0.001), time to gas passage, defecation, and solid food intake and length of hospital stay were significantly shorter in the laparoscopic group than the open group (P<0.05). According to the univariate and multivariate analysis, laparoscopic surgery did not have an effect on local recurrence but had a favorable effect on survival rates. Laparoscopic rectal surgery has advantages over open surgery with respect to short-term and long-term clinical results and when performed in high-volume centers.

Endocrine pathology, Jan 2, 2016

This study investigated the impact of phosphohistone-H3 (PHH3)-assisted mitotic count by comparin... more This study investigated the impact of phosphohistone-H3 (PHH3)-assisted mitotic count by comparing its performance with conventional mitotic count and Ki67 score as well as the status of distant metastasis. A total of 43 surgically resected pancreatic neuroendocrine tumors (panNET) with complete follow-up information has been subjected to a standardized assessment with respect to mitotic count (both conventional and PHH3-assisted) and Ki67 score. Five participants assessed mitotic count and the time spent was recorded in both methods. All tumors were assigned to a G1 category of mitotic rate on conventional mitotic count that failed to identify three tumors with a G2 category of mitotic rate on PHH3. Near-perfect and fair agreements were achieved among observers when using PHH3 and conventional method, respectively. The mean time spent to determine mitotic count on PHH3-stained slides was significantly shorter (p < 0.001). The performance of PHH3-assisted mitotic grade category w...

Medicine, 2016

The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disea... more The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disease-free survival period and survival. For this aim, obtainment of negative circumferential radial margin (CRM) plays an important role. This study evaluated predictive factors for positive CRM status and its effect on patient survival in mid- and distal rectal tumors.Patients who underwent curative resection for rectal cancer were included. The main factors were demographic data, tumor location, surgical technique, neoadjuvant therapy, tumor diameter, tumor depth, lymph node metastasis, mesorectal integrity, CRM, the rate of local recurrence, distant metastasis, and overall and disease-free survival. Statistical analyses were performed by using the Chi-squared test, Fisher exact test, Student t test, Mann-Whitney U test and the Mantel-Cox log-rank sum test.A total of 420 patients were included, 232 (55%) of whom were male. We observed no significant differences in patient characteristics...

BMC Surgery, 2015

Background: Splenectomy after combined colosplenic trauma or iatrogenic splenic injury during col... more Background: Splenectomy after combined colosplenic trauma or iatrogenic splenic injury during colorectal surgery associates with worse short-and long-term outcomes, including reduced survival in patients with colorectal cancer. Splenic autotransplantation may improve the outcomes of such patients. Omental splenic transplantation is the standard procedure but may be difficult when performing laparoscopic colorectal surgery or when total or subtotal omentectomy is required. This animal model study was performed to evaluate the impact of splenic autotransplantation to the groin area on colonic wound healing. Methods: Thirty rats were divided into three groups of ten animals. One group underwent colon anastomosis and sham splenectomy, the second underwent colon anastomosis and splenectomy, and the third underwent colon anastomosis, splenectomy, and intramuscular autotransplantation of the spleen. On postoperative day 7, anastomotic healing was evaluated by measuring bursting pressure and hydroxyproline levels. The third group was subjected to scintigraphy before sacrifice to assess whether the transplant was functional. Results: The mortality rates of the sham, splenectomized, and transplanted animals were 0 %, 30 %, and 20 %, respectively: the splenectomized animals had significantly lower mean bursting pressures than the other two groups (p = 0.002). The mean hydroxyproline levels of the three groups were 467.4, 335.3, and 412.7 mg hydroxyproline/g protein, respectively (p = 0.0856). Nine of the ten transplanted animals (90 %) had splenic activity on scintigraphy. Conclusions: Splenectomy impaired the healing of the colonic anastomosis. This effect was largely reversed by splenic autotransplantation. Intramuscular autotransplantation to the groin area appears to be feasible and effective.

International Journal of Molecular Sciences, 2015

Circulating nucleic acids (CNAs) are under investigation as a liquid biopsy in cancer as potentia... more Circulating nucleic acids (CNAs) are under investigation as a liquid biopsy in cancer as potential non-invasive biomarkers, as stable structure in circulation nucleosomes could be valuable sources for detection of cancer-specific alterations in histone modifications. Our interest is in histone methylation marks with a focus on colorectal cancer, one of the leading cancers respective the incidence and mortality. Our previous work included the analysis of trimethylations of lysine 9 on histone 3 (H3K9me3) and of lysine 20 on histone 4 (H4K20me3) by chromatin immuno-precipitation-related PCR in circulating nucleosomes. Here we asked whether global immunologic measurement of histone marks in circulation could be a suitable approach to show their potential as biomarkers. In addition to H3K9me3 and H4K20me3 we also measured H3K27me3 in plasma samples from CRC patients (n = 63) and cancer free individuals (n = 40) by ELISA-based methylation assays. Our results show that of three marks, the amounts of H3K27me3 (p = 0.04) and H4K20me3 (p < 0.001) were significantly lower in CRC patients than in healthy controls. For H3K9me3 similar amounts were measured in both groups. Areas under the curve (AUC) in receiver operating characteristic (ROC) curves indicating the power of CRC detection were 0.620 for H3K27me3, 0.715 for H4K20me3 and 0.769 for the combination of both markers. In conclusion, findings of this preliminary study reveal the potential of blood-based detection of CRC by quantification of histone methylation marks and the additive effect of the marker combination.