Claudia Garrido - Academia.edu (original) (raw)

Papers by Claudia Garrido

Research paper thumbnail of Rhabdomyosarcoma in low‐ and middle‐income countries: A report from the Asociacion de Hemato‐oncología Pediatrica de Centro América (AHOPCA)

Pediatric Blood & Cancer, Mar 16, 2022

This report describes the results of an observational study dedicated to rhabdomyosarcoma develop... more This report describes the results of an observational study dedicated to rhabdomyosarcoma developed by the Asociación de Hemato-oncología Pediatrica de Centro América (AHOPCA) between 2001 and 2018. Overall, 337 previously untreated patients < 18 years old were included in the analysis; 58% had unresected disease, and 19% were metastatic at diagnosis. With a median follow-up of 6.6 years, five-year event-free and overall survival rates were 30% and 33%, respectively. Local progression/relapse was the main cause of treatment failure.

Research paper thumbnail of Rhabdomyosarcoma in low‐ and middle‐income countries: A report from the Asociacion de Hemato‐oncología Pediatrica de Centro América (AHOPCA)

Pediatric Blood & Cancer, 2022

This report describes the results of an observational study dedicated to rhabdomyosarcoma develop... more This report describes the results of an observational study dedicated to rhabdomyosarcoma developed by the Asociación de Hemato-oncología Pediatrica de Centro América (AHOPCA) between 2001 and 2018. Overall, 337 previously untreated patients < 18 years old were included in the analysis; 58% had unresected disease, and 19% were metastatic at diagnosis. With a median follow-up of 6.6 years, five-year event-free and overall survival rates were 30% and 33%, respectively. Local progression/relapse was the main cause of treatment failure.

Research paper thumbnail of International collaborations in cancer control and the Third International Cancer Control Congress

Tumori Journal, 2009

Over the past few decades, there has been growing support for the idea that cancer needs an inter... more Over the past few decades, there has been growing support for the idea that cancer needs an interdisciplinary approach. Therefore, the international cancer community has developed several strategies as outlined in the WHO non-communicable diseases Action Plan (which includes cancer control) as the World Health Assembly and the UICC World Cancer Declaration, which both include primary prevention, early diagnosis, treatment, and palliative care. This paper highlights experiences/ideas in cancer control for international collaborations between low, middle, and high income countries, including collaborations between the European Union (EU) and African Union (AU) Member States, the Latin-American and Caribbean countries, and the Eastern Mediterranean countries. These proposals are presented within the context of the global vision on cancer control set forth by WHO in partnership with the International Union Against Cancer (UICC), in addition to issues that should be considered for collab...

Research paper thumbnail of Implementation of pediatric population-based cancer registries (PBCR) in Central America (CA)

Journal of Clinical Oncology, 2015

e12624 Background: With progress made towards meeting the Millennium Development Goals, cancer is... more e12624 Background: With progress made towards meeting the Millennium Development Goals, cancer is now an important contributor to childhood mortality in CA. Hospital-based data suggests regional differences in cancer incidence compared to estimates in Europe and North America. PBCR are needed for rational cancer planning and to support descriptive and molecular epidemiology research in childhood cancer specific to the region. Methods: Two pediatric PBCR were created in Guatemala (GU) and El Salvador (ES) in 2013. A four-step process was followed. First, training of coordinators and registrars was completed, and CanReg5 was implemented with the support of the International Association of Cancer Registries and the Global Initiative for Cancer Registry Development. Second, the support of health authorities was secured to ensure regulatory compliance and long-term sustainability. Third, involvement of public and private stakeholders (oncologists, pathologists, and laboratories) was sought to ensure access to ...

Research paper thumbnail of Outcome of pediatric non‐Hodgkin lymphoma in Central America: A report of the Association of Pediatric Hematology Oncology of Central America (AHOPCA)

Pediatric Blood & Cancer, 2019

Background: Treating B-non-Hodgkin lymphoma (NHL) in lower-income countries is challenging becaus... more Background: Treating B-non-Hodgkin lymphoma (NHL) in lower-income countries is challenging because of imprecise diagnosis, the increased risk of fatal toxicity associated with advanced disease at presentation, and limited supportive care. Procedure: Central American patients with newly diagnosed stage I or II B-NHL received a modified BFM regimen including a prephase (prednisone, cyclophosphamide) followed by A/B/A courses (A: cytarabine, dexamethasone, etoposide, ifosfamide, methotrexate, and intrathecal therapy; B: cyclophosphamide, dexamethasone, doxorubicin, methotrexate, and intrathecal therapy). Those with stage III or IV NHL received additional courses (B/A/B), intensified for stage IV disease by additional vincristine and methotrexate doses. Patients in poor condition received a second prephase treatment before their chemotherapy courses.

Research paper thumbnail of Advancing Reliable Data for Cancer Control in the Central America Four Region

Journal of Global Oncology, 2017

The Central America Four (CA-4) region, comprising Guatemala, Honduras, El Salvador, and Nicaragu... more The Central America Four (CA-4) region, comprising Guatemala, Honduras, El Salvador, and Nicaragua, is the largest low- and middle-income country region in the Western Hemisphere, with over 36 million inhabitants. The CA-4 nations share a common geography, history, language, and development indices, and unified with open borders in 2006. The growing CA-4 cancer burden among the noncommunicable diseases is expected to increase 73% by 2030, which argues for a regional approach to cancer control. This has driven efforts to establish population-based cancer registries as a central component of the cancer control plans. The involvement of international and academic partners in an array of initiatives to improve cancer information and control in the CA-4 has accelerated over the past several years. Existing data underscore that the infectious cancers (cervical, stomach, and liver) are a particular burden. All four countries have committed to establishing regional population-based cancer r...

Research paper thumbnail of The treatment of childhood acute lymphoblastic leukemia in Guatemala: Biologic features, treatment hurdles, and results

Cancer, Feb 28, 2016

The National Pediatric Oncology Unit (UNOP) is the only pediatric hemato-oncology center in Guate... more The National Pediatric Oncology Unit (UNOP) is the only pediatric hemato-oncology center in Guatemala. Patients ages 1 to 17 years with acute lymphoblastic leukemia (ALL) were treated according to modified ALL Intercontinental Berlin-Frankfurt-Münster (IC-BFM) 2002 protocol. Risk classification was based on age, white blood cell count, immunophenotype, genetics (when available), and early response to therapy. From July 2007 to June 2014, 787 patients were treated, including 160 who had standard-risk ALL, 450 who had intermediate-risk ALL, and 177 who had high-risk ALL. The induction death rate was 6.6%, and the remission rate was 92.9%. The rates of death and treatment abandonment during first complete remission were 4.8% and 2.5%, respectively. At a median observation time of 3.6 years, and with abandonment considered an event, the 5-year event-free survival and overall survival estimates ( ± standard error) were 56.2% ± 2.1% and 64.1% ± 2.1%, respectively, with a 5-year cumulative...

Research paper thumbnail of Paediatric cancer stage in population-based cancer registries: the Toronto consensus principles and guidelines

The Lancet Oncology, 2016

Research paper thumbnail of Anaplastic large cell lymphoma in Central America: A report from the Central American Association of Pediatric Hematology Oncology (AHOPCA)

Pediatric Blood & Cancer, 2015

Research paper thumbnail of Frequency of thiopurine S-methyltransferase mutant alleles in indigenous and admixed Guatemalan patients with acute lymphoblastic leukemia

Medical Oncology, 2013

Thiopurine S-methyltransferase (TPMT) polymorphisms affect the enzyme's activity and are predicti... more Thiopurine S-methyltransferase (TPMT) polymorphisms affect the enzyme's activity and are predictive for the efficacy and toxicity of thiopurine treatment of acute lymphoblastic leukemia (ALL), autoimmune diseases and organ transplants. Because inter-ethnic differences in the distribution of these polymorphisms have been documented, we sequenced the TMPT gene in 95 Guatemalans, yet identified no new alleles. We also determined the frequency of the TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C alleles in 270 admixed and 177 indigenous pediatric patients with ALL and healthy subjects from Guatemala using TaqMan assays and DNA sequencing. Among the 447 subjects genotyped, 10.0% of the ALL cases and 13.6% of the healthy controls were heterozygous for one of the four TPMT variants screened. The genotype frequencies in ALL and control populations were 0.7% and 1.7% for TPMT*1/*2, 7.4% and 10% for TPMT*1/*3A, 0.3% and 0% for TPMT*1/*B, and 1.5% and 1.1% for TPMT*1/*C, respectively (p= 0.30). No statistically significant differences between admixed and indigenous ALL (p= 0.67) or controls (p= 0.41) groups were detected; however 17% of the admixed healthy group bore one TPMT mutant allele and they have one of the highest reported frequencies of TPMT mutant allele carriers. Because of the clinical implications of these variants for therapeutic response, TPMT allele testing should be considered in all Guatemalan patients to reduce adverse side-effects from thiopurine drug treatments.

Research paper thumbnail of Increased incidence and disparity of diagnosis of retinoblastoma patients in Guatemala

Research paper thumbnail of Treating Pediatric soft tissue sarcomas in a country with limited resources: The experience of the Unidad Nacional de Oncologia Pediatrica in Guatemala

Pediatric Blood & Cancer, 2008

About 250-300 children with newly diagnosed cancer are treated each year at the Unidad Nacional d... more About 250-300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country. We reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007. Most of the RMS patients had advanced disease at diagnosis (87% groups III-IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; or =5 cm, and those with localized disease. Overall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome.

Research paper thumbnail of Neuro-Oncology in Developing Countries

Neuro-Oncology, 2012

Medulloblastoma (MB) accounts for approximately 20% of pediatric central nervous system neoplasms... more Medulloblastoma (MB) accounts for approximately 20% of pediatric central nervous system neoplasms. Current standard management includes safe maximal surgical resection followed by craniospinal irradiation (CSI) with chemotherapeutic radiosensitization followed by adjuvant chemotherapy. The overall and event free survival rates depend upon many prognostic factors. PURPOSE: To investigate treatment outcome for newly diagnosed MB patients treated at the Children's Cancer Hospital Egypt 57357 (CCHE) and to determine the working prognostic factors. PATIENTS AND METHODS: This study included all patients; treated at the CCHE; with histologically confirmed MB between Jan, 2008, and Jan, 2011. The Median age of the 73 (49 males (67.1%); 24 females (32.9%)) patients was 7 years (range 3-17). The median follow up period was 16 months (range 1-41). Risk stratification based upon initial Chang's stage, degree of surgical resection and histopathology. All patients had surgical resection of the tumor. Seventy one patients (97.3%) received the allocated radiochemotherapy. One patient was lost follow up and one patient died before radiotherapy. Risk adapted treatment were performed via 2 treatment protocols (Standard and high risk). The 2 protocols differ in the dose of craniospinal irradiation and the chemotherapy regimen. RESULTS: The 3-year overall (OS) and event-free (EFS) survival differed significantly between average-risk and high-risk patients (p ¼ 0.024 and 0.003), with 77.8% and 82% OS and EFS for the average risk group respectively and 56.8 % and 50.5% OS and EFS for high-risk group respectively. The histopathology classification showed significant difference in both overall survivals: desmoplastic ¼ 75%, classic ¼ 71.6%, anaplastic ¼ 47.6%, (p ¼ 0.028) and event free survival: desmoplastic ¼ 75%, classic ¼ 68.9%, anaplastic ¼ 40.5%, (p ¼ 0.007). CONCLUSION: Preliminary results of risk adapted treatment for children suffering from medulloblastoma are encouraging and depending upon the clinical prognostic factors. Further follow up is needed to investigate further prognostic factors.

Research paper thumbnail of Reproduktionssteuerung bei der parasitischen Bienenmilbe Varroa destructor Anderson & Trueman 2000 (ehemals Varroa jacobsoni Oudemans) /

Thesis (doctoral)--Universität Hohenheim, 2004.

Research paper thumbnail of Socioeconomic status and global variations in the incidence of neuroblastoma: call for support of population-based cancer registries in low-middle-income countries

Pediatric Blood & Cancer, 2016

Global variations in the incidence of pediatric cancers have been described; however, the causes ... more Global variations in the incidence of pediatric cancers have been described; however, the causes of such differences are not known. We investigated the relationship between the incidence of embryonal tumors and human development index on a global scale. Increasing incidence of neuroblastoma correlates significantly with an increasing index of human development, with greater incidence among countries with high socioeconomic development, in apparent contrast to the incidence of retinoblastoma. While more data are needed to corroborate this observation, our findings suggest new avenues for etiological research and serve as a call for support of populationbased cancer registries in low-middle-income countries.

Research paper thumbnail of Changing Pediatric Oncology Outcomes in Low-Income Countries from 23% to 60% Efs in 10 Years: Guatemala

Research paper thumbnail of Treating Pediatric soft tissue sarcomas in a country with limited resources: The experience of the Unidad Nacional de Oncologia Pediatrica in Guatemala

Pediatric Blood & Cancer, 2008

BackgroundAbout 250–300 children with newly diagnosed cancer are treated each year at the Unidad ... more BackgroundAbout 250–300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country.About 250–300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country.Patients and MethodsWe reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007.We reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007.ResultsMost of the RMS patients had advanced disease at diagnosis (87% groups III–IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors ≤5 cm, and those with localized disease.Most of the RMS patients had advanced disease at diagnosis (87% groups III–IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors ≤5 cm, and those with localized disease.ConclusionsOverall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome. Pediatr Blood Cancer 2008;51:760–764. © 2008 Wiley-Liss, Inc.Overall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome. Pediatr Blood Cancer 2008;51:760–764. © 2008 Wiley-Liss, Inc.

Research paper thumbnail of Rhabdomyosarcoma in low‐ and middle‐income countries: A report from the Asociacion de Hemato‐oncología Pediatrica de Centro América (AHOPCA)

Pediatric Blood & Cancer, Mar 16, 2022

This report describes the results of an observational study dedicated to rhabdomyosarcoma develop... more This report describes the results of an observational study dedicated to rhabdomyosarcoma developed by the Asociación de Hemato-oncología Pediatrica de Centro América (AHOPCA) between 2001 and 2018. Overall, 337 previously untreated patients < 18 years old were included in the analysis; 58% had unresected disease, and 19% were metastatic at diagnosis. With a median follow-up of 6.6 years, five-year event-free and overall survival rates were 30% and 33%, respectively. Local progression/relapse was the main cause of treatment failure.

Research paper thumbnail of Rhabdomyosarcoma in low‐ and middle‐income countries: A report from the Asociacion de Hemato‐oncología Pediatrica de Centro América (AHOPCA)

Pediatric Blood & Cancer, 2022

This report describes the results of an observational study dedicated to rhabdomyosarcoma develop... more This report describes the results of an observational study dedicated to rhabdomyosarcoma developed by the Asociación de Hemato-oncología Pediatrica de Centro América (AHOPCA) between 2001 and 2018. Overall, 337 previously untreated patients < 18 years old were included in the analysis; 58% had unresected disease, and 19% were metastatic at diagnosis. With a median follow-up of 6.6 years, five-year event-free and overall survival rates were 30% and 33%, respectively. Local progression/relapse was the main cause of treatment failure.

Research paper thumbnail of International collaborations in cancer control and the Third International Cancer Control Congress

Tumori Journal, 2009

Over the past few decades, there has been growing support for the idea that cancer needs an inter... more Over the past few decades, there has been growing support for the idea that cancer needs an interdisciplinary approach. Therefore, the international cancer community has developed several strategies as outlined in the WHO non-communicable diseases Action Plan (which includes cancer control) as the World Health Assembly and the UICC World Cancer Declaration, which both include primary prevention, early diagnosis, treatment, and palliative care. This paper highlights experiences/ideas in cancer control for international collaborations between low, middle, and high income countries, including collaborations between the European Union (EU) and African Union (AU) Member States, the Latin-American and Caribbean countries, and the Eastern Mediterranean countries. These proposals are presented within the context of the global vision on cancer control set forth by WHO in partnership with the International Union Against Cancer (UICC), in addition to issues that should be considered for collab...

Research paper thumbnail of Implementation of pediatric population-based cancer registries (PBCR) in Central America (CA)

Journal of Clinical Oncology, 2015

e12624 Background: With progress made towards meeting the Millennium Development Goals, cancer is... more e12624 Background: With progress made towards meeting the Millennium Development Goals, cancer is now an important contributor to childhood mortality in CA. Hospital-based data suggests regional differences in cancer incidence compared to estimates in Europe and North America. PBCR are needed for rational cancer planning and to support descriptive and molecular epidemiology research in childhood cancer specific to the region. Methods: Two pediatric PBCR were created in Guatemala (GU) and El Salvador (ES) in 2013. A four-step process was followed. First, training of coordinators and registrars was completed, and CanReg5 was implemented with the support of the International Association of Cancer Registries and the Global Initiative for Cancer Registry Development. Second, the support of health authorities was secured to ensure regulatory compliance and long-term sustainability. Third, involvement of public and private stakeholders (oncologists, pathologists, and laboratories) was sought to ensure access to ...

Research paper thumbnail of Outcome of pediatric non‐Hodgkin lymphoma in Central America: A report of the Association of Pediatric Hematology Oncology of Central America (AHOPCA)

Pediatric Blood & Cancer, 2019

Background: Treating B-non-Hodgkin lymphoma (NHL) in lower-income countries is challenging becaus... more Background: Treating B-non-Hodgkin lymphoma (NHL) in lower-income countries is challenging because of imprecise diagnosis, the increased risk of fatal toxicity associated with advanced disease at presentation, and limited supportive care. Procedure: Central American patients with newly diagnosed stage I or II B-NHL received a modified BFM regimen including a prephase (prednisone, cyclophosphamide) followed by A/B/A courses (A: cytarabine, dexamethasone, etoposide, ifosfamide, methotrexate, and intrathecal therapy; B: cyclophosphamide, dexamethasone, doxorubicin, methotrexate, and intrathecal therapy). Those with stage III or IV NHL received additional courses (B/A/B), intensified for stage IV disease by additional vincristine and methotrexate doses. Patients in poor condition received a second prephase treatment before their chemotherapy courses.

Research paper thumbnail of Advancing Reliable Data for Cancer Control in the Central America Four Region

Journal of Global Oncology, 2017

The Central America Four (CA-4) region, comprising Guatemala, Honduras, El Salvador, and Nicaragu... more The Central America Four (CA-4) region, comprising Guatemala, Honduras, El Salvador, and Nicaragua, is the largest low- and middle-income country region in the Western Hemisphere, with over 36 million inhabitants. The CA-4 nations share a common geography, history, language, and development indices, and unified with open borders in 2006. The growing CA-4 cancer burden among the noncommunicable diseases is expected to increase 73% by 2030, which argues for a regional approach to cancer control. This has driven efforts to establish population-based cancer registries as a central component of the cancer control plans. The involvement of international and academic partners in an array of initiatives to improve cancer information and control in the CA-4 has accelerated over the past several years. Existing data underscore that the infectious cancers (cervical, stomach, and liver) are a particular burden. All four countries have committed to establishing regional population-based cancer r...

Research paper thumbnail of The treatment of childhood acute lymphoblastic leukemia in Guatemala: Biologic features, treatment hurdles, and results

Cancer, Feb 28, 2016

The National Pediatric Oncology Unit (UNOP) is the only pediatric hemato-oncology center in Guate... more The National Pediatric Oncology Unit (UNOP) is the only pediatric hemato-oncology center in Guatemala. Patients ages 1 to 17 years with acute lymphoblastic leukemia (ALL) were treated according to modified ALL Intercontinental Berlin-Frankfurt-Münster (IC-BFM) 2002 protocol. Risk classification was based on age, white blood cell count, immunophenotype, genetics (when available), and early response to therapy. From July 2007 to June 2014, 787 patients were treated, including 160 who had standard-risk ALL, 450 who had intermediate-risk ALL, and 177 who had high-risk ALL. The induction death rate was 6.6%, and the remission rate was 92.9%. The rates of death and treatment abandonment during first complete remission were 4.8% and 2.5%, respectively. At a median observation time of 3.6 years, and with abandonment considered an event, the 5-year event-free survival and overall survival estimates ( ± standard error) were 56.2% ± 2.1% and 64.1% ± 2.1%, respectively, with a 5-year cumulative...

Research paper thumbnail of Paediatric cancer stage in population-based cancer registries: the Toronto consensus principles and guidelines

The Lancet Oncology, 2016

Research paper thumbnail of Anaplastic large cell lymphoma in Central America: A report from the Central American Association of Pediatric Hematology Oncology (AHOPCA)

Pediatric Blood & Cancer, 2015

Research paper thumbnail of Frequency of thiopurine S-methyltransferase mutant alleles in indigenous and admixed Guatemalan patients with acute lymphoblastic leukemia

Medical Oncology, 2013

Thiopurine S-methyltransferase (TPMT) polymorphisms affect the enzyme's activity and are predicti... more Thiopurine S-methyltransferase (TPMT) polymorphisms affect the enzyme's activity and are predictive for the efficacy and toxicity of thiopurine treatment of acute lymphoblastic leukemia (ALL), autoimmune diseases and organ transplants. Because inter-ethnic differences in the distribution of these polymorphisms have been documented, we sequenced the TMPT gene in 95 Guatemalans, yet identified no new alleles. We also determined the frequency of the TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C alleles in 270 admixed and 177 indigenous pediatric patients with ALL and healthy subjects from Guatemala using TaqMan assays and DNA sequencing. Among the 447 subjects genotyped, 10.0% of the ALL cases and 13.6% of the healthy controls were heterozygous for one of the four TPMT variants screened. The genotype frequencies in ALL and control populations were 0.7% and 1.7% for TPMT*1/*2, 7.4% and 10% for TPMT*1/*3A, 0.3% and 0% for TPMT*1/*B, and 1.5% and 1.1% for TPMT*1/*C, respectively (p= 0.30). No statistically significant differences between admixed and indigenous ALL (p= 0.67) or controls (p= 0.41) groups were detected; however 17% of the admixed healthy group bore one TPMT mutant allele and they have one of the highest reported frequencies of TPMT mutant allele carriers. Because of the clinical implications of these variants for therapeutic response, TPMT allele testing should be considered in all Guatemalan patients to reduce adverse side-effects from thiopurine drug treatments.

Research paper thumbnail of Increased incidence and disparity of diagnosis of retinoblastoma patients in Guatemala

Research paper thumbnail of Treating Pediatric soft tissue sarcomas in a country with limited resources: The experience of the Unidad Nacional de Oncologia Pediatrica in Guatemala

Pediatric Blood & Cancer, 2008

About 250-300 children with newly diagnosed cancer are treated each year at the Unidad Nacional d... more About 250-300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country. We reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007. Most of the RMS patients had advanced disease at diagnosis (87% groups III-IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; or =5 cm, and those with localized disease. Overall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome.

Research paper thumbnail of Neuro-Oncology in Developing Countries

Neuro-Oncology, 2012

Medulloblastoma (MB) accounts for approximately 20% of pediatric central nervous system neoplasms... more Medulloblastoma (MB) accounts for approximately 20% of pediatric central nervous system neoplasms. Current standard management includes safe maximal surgical resection followed by craniospinal irradiation (CSI) with chemotherapeutic radiosensitization followed by adjuvant chemotherapy. The overall and event free survival rates depend upon many prognostic factors. PURPOSE: To investigate treatment outcome for newly diagnosed MB patients treated at the Children's Cancer Hospital Egypt 57357 (CCHE) and to determine the working prognostic factors. PATIENTS AND METHODS: This study included all patients; treated at the CCHE; with histologically confirmed MB between Jan, 2008, and Jan, 2011. The Median age of the 73 (49 males (67.1%); 24 females (32.9%)) patients was 7 years (range 3-17). The median follow up period was 16 months (range 1-41). Risk stratification based upon initial Chang's stage, degree of surgical resection and histopathology. All patients had surgical resection of the tumor. Seventy one patients (97.3%) received the allocated radiochemotherapy. One patient was lost follow up and one patient died before radiotherapy. Risk adapted treatment were performed via 2 treatment protocols (Standard and high risk). The 2 protocols differ in the dose of craniospinal irradiation and the chemotherapy regimen. RESULTS: The 3-year overall (OS) and event-free (EFS) survival differed significantly between average-risk and high-risk patients (p ¼ 0.024 and 0.003), with 77.8% and 82% OS and EFS for the average risk group respectively and 56.8 % and 50.5% OS and EFS for high-risk group respectively. The histopathology classification showed significant difference in both overall survivals: desmoplastic ¼ 75%, classic ¼ 71.6%, anaplastic ¼ 47.6%, (p ¼ 0.028) and event free survival: desmoplastic ¼ 75%, classic ¼ 68.9%, anaplastic ¼ 40.5%, (p ¼ 0.007). CONCLUSION: Preliminary results of risk adapted treatment for children suffering from medulloblastoma are encouraging and depending upon the clinical prognostic factors. Further follow up is needed to investigate further prognostic factors.

Research paper thumbnail of Reproduktionssteuerung bei der parasitischen Bienenmilbe Varroa destructor Anderson & Trueman 2000 (ehemals Varroa jacobsoni Oudemans) /

Thesis (doctoral)--Universität Hohenheim, 2004.

Research paper thumbnail of Socioeconomic status and global variations in the incidence of neuroblastoma: call for support of population-based cancer registries in low-middle-income countries

Pediatric Blood & Cancer, 2016

Global variations in the incidence of pediatric cancers have been described; however, the causes ... more Global variations in the incidence of pediatric cancers have been described; however, the causes of such differences are not known. We investigated the relationship between the incidence of embryonal tumors and human development index on a global scale. Increasing incidence of neuroblastoma correlates significantly with an increasing index of human development, with greater incidence among countries with high socioeconomic development, in apparent contrast to the incidence of retinoblastoma. While more data are needed to corroborate this observation, our findings suggest new avenues for etiological research and serve as a call for support of populationbased cancer registries in low-middle-income countries.

Research paper thumbnail of Changing Pediatric Oncology Outcomes in Low-Income Countries from 23% to 60% Efs in 10 Years: Guatemala

Research paper thumbnail of Treating Pediatric soft tissue sarcomas in a country with limited resources: The experience of the Unidad Nacional de Oncologia Pediatrica in Guatemala

Pediatric Blood & Cancer, 2008

BackgroundAbout 250–300 children with newly diagnosed cancer are treated each year at the Unidad ... more BackgroundAbout 250–300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country.About 250–300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country.Patients and MethodsWe reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007.We reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007.ResultsMost of the RMS patients had advanced disease at diagnosis (87% groups III–IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors ≤5 cm, and those with localized disease.Most of the RMS patients had advanced disease at diagnosis (87% groups III–IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors ≤5 cm, and those with localized disease.ConclusionsOverall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome. Pediatr Blood Cancer 2008;51:760–764. © 2008 Wiley-Liss, Inc.Overall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome. Pediatr Blood Cancer 2008;51:760–764. © 2008 Wiley-Liss, Inc.