Focal-to-bilateral tonic-clonic seizures and High-grade CMV-infection are poor survival predictors in Tumor-related Epilepsy Adult-type diffuse gliomas-A single-center study and literature review.

Introduction: Previous studies have reported a correlation between a high-grade CMV-infection and an unfavorable prognosis in glioblastoma (GB). Coversely, epilepsy has been associated with a more favorable outcome in GB patients. Despites epilepsy and CMV share similar molecular mechanisms in GB tumoral microenvironment, the correlation between Tumor-Related-Epilepsy (TRE) and CMVinfection remains unexplored. The aim of our study is to examine the correlation between the dregree of CMV infection and seizure types on the survival of TRE Adult-type-diffuse-glioma. To achieve this objective, we conducted a comprehensive literature review to assess our results regarding previous publications. Methods: We conducted a retrospective-observational study on TRE Adult-type-diffuse-gliomas treated at a single center in Mexico from 2010 to 2018. Tumor tissue and cDNA were analyzed by immunochemistry (IHC) for CMV (IE and LA antigens) at the Karolinska Institute in Sweden, and RT-PCR for CMV-gB in Torreon Mexico, respectively. Bivariate analysis (X2-test) was performed to evaluate the association between subtypes of Adult-type-diffuse-glioma (IDH-mut grade 4 astrocytoma vs. IDH-wt glioblastoma) and the following variables: type of hemispheric involvement (mesial vs. neocortical involvement), degree of CMV infection (<25%vs. >25% infected-tumoral cells) and seizure types [Focal awareness, focal impaired awareness, and FBTCS]. Kaplan Meier and Cox analyses were performed to determine the risk, p < 0.05 was considered statistically significant. Results: Sixty patients with TRE Adult type diffuse gliomas were included (80% IDH-wt glioblastoma and 20% IDH-mut grade 4astrocytomas). The mean age was 61.5 SD ± 18.4, and 57% were male. Fifty percent of the patients presented with mesial involvement of the hemysphere. Seizure types included focal awareness (15%), focal impaired awareness (43.3%), and FBTCS (41.7%). Ninety percent of cases were treated with Levetiracetam and 33.3% presented Engel-IA postoperative seizure control. More than 90% of samples were positive for CMV-immunohistochemistry (IHC). However, all cDNA analyzed by RT-PCR return negative results. The median of overall survival (OS) was 15 months. High-grade CMV-IE infection (14 vs. 25 months, p<0.001), mesial involvement (12 vs. 18 months, p<0.001), and FBTCS were associated with worse OS (9 vs.18 months for non-FBTCS). Multivariate analysis demonstrated that high-grade CMV infection (HR = 3.689, p=0.002) and FBTCS (HR=7.007, p<0.001) were independent unfavorable survival factors. Conclusions: CMV induces a proinflammatory tumoral microenvironment that contributes to the developmet of epilepsy. Tumor progression could be associated not only with a higher degree of CMV infection but also to epileptogenesis, resulting in a seizure phenotype chracterized by FBTCS and poor survival outcomes. This study represents the first survival analysis in Latin America to include a representative sample of TRE Adult-type diffuse gliomas considering CMV-infection-degree and distinguishing features (such as FBTCS) that might have potential clinical relevance in this group of patients. Further prospective studies are required to validate these results.

[Extremity soft tissue sarcoma: does surgical margin impact survival?] / Sarcomas de tejidos blandos en las extremidades: ¿el margen quirúrgico impacta la sobrevida?

Objective: To define the impact of surgical margins on local recurrence (LR), distant recurrence (DR) and overall survival (OS) in patients with soft tissue sarcomas of the extremities (eSTS). Method: Patients treated for a primary eSTS from 2006 to 2010 were analyzed. Rates of local recurrence, distant recurrence, and overall survival were estimated using the Kaplan-Meier method. The association of possible prognostic factors such as local recurrence, metastasis, and survival was performed using the Cox proportional hazards model. Results: 128 patients were analyzed. The surgical margins were positive (R1 resection) in 22.7% and negative in 77.3%. The LR was 27%, the DR was 13% (70% of the population was free of disease at 5 years) and OS at 5 years was 84%. The prognostic factors for OS at 5 years were clinical stage, type and histological grade. The surgical margin had no impact on OS. Conclusions: Although an adequate oncological resection cannot be underestimated, this should be considered in the decision of the optimal treatment of eSTS when amputation or significant functional impairment of the limb is required to obtain negative surgical margins.

Objetivo: Definir el impacto de los márgenes quirúrgicos sobre la recurrencia local (RL), la recurrencia a distancia (RD) y la supervivencia global (SG) en pacientes con sarcomas de tejidos blandos de las extremidades (STBe). Método: Se analizaron pacientes tratados por un STBe primario desde 2006 hasta 2010. Las tasas de recurrencia local, recurrencia a distancia y sobrevida global se estimaron mediante el método de Kaplan-Meier. La asociación de posibles factores pronósticos como recidiva local, metástasis y supervivencia se realizó mediante el modelo de riesgos proporcionales de Cox. Resultados: Se analizaron 128 pacientes. Los márgenes quirúrgicos fueron positivos (resección R1) en el 22.7% y negativos en el 77.3%. La RL fue del 27% y la RD fue del 13% (el 70% de la población está libre de enfermedad a 5 años) y la SG a 5 años fue del 84%. Los factores pronósticos para la SG a 5 años fueron el estadio clínico, el tipo y el grado histológico. El margen quirúrgico no tuvo impacto en la SG. Conclusiones: Aunque no se puede subestimar una resección oncológica adecuada, esto se debe considerar en la decisión del tratamiento óptimo de los STBe cuando se requiere una amputación o un deterioro funcional significativo de la extremidad para obtener márgenes quirúrgicos negativos.

High expression of both desmoplastic stroma and epithelial to mesenchymal transition markers associate with shorter survival in pancreatic ductal adenocarcinoma.

Desmoplastic stroma (DS) and the epithelial-to-mesenchymal transition (EMT) play a key role in pancreatic ductal adenocarcinoma (PDAC) progression. To date, however, the combined expression of DS and EMT markers, and their association with variations in survival within each clinical stage and degree of tumor differentiation is unknown. The purpose of this study was to investigate the association between expression of DS and EMT markers and survival variability in patients diagnosed with PDAC. We examined the expression levels of DS markers alpha smooth muscle actin (α-SMA), fibronectin, and vimentin, and the EMT markers epithelial cell adhesion molecule (EPCAM), pan-cytokeratin, and vimentin, by immunohistochemistry using a tissue microarray of a retrospective cohort of 25 patients with PDAC. The results were examined for association with survival by clinical stage and by degree of tumor differentiation. High DS markers expression -α-SMA, fibronectin, and vimentin- was associated with decreased survival at intermediate and advanced clinical stages (p=0.006-0.03), as well as with both poorly and moderately differentiated tumor grades (p=0.01-0.02). Interestingly, the same pattern was observed for EMT markers, i.e., EPCAM, pan-cytokeratin, and vimentin (p=0.00008-0.03). High expression of DS and EMT markers within each clinical stage and degree of tumor differentiation was associated with lower PDAC survival. Evaluation of these markers may have a prognostic impact on survival time variation in patients with PDAC.

Giant liver teratoma with gliosis peritonei treated by right extended hepatectomy: Overview and case report.

Germ cell tumors (GCTs) are considered as extragonadal if there is no evidence of a primary tumor in the testes or ovaries. GCTs can be classified as seminomas, non-seminomatous, mature teratomas, and immature teratomas based upon histology. Mature teratomas are generally found in prepuberal children. Less than 1% of them have been reported in the gastrointestinal tract and liver. Liver teratomas are extremely rare. There are only 11 cases reported in adults up to 2018. Isolated liver metastasis of ovarian teratoma is also very rare. We present a case of a late metachronous recurrence of liver cystic teratoma with gliosis peritonei in a female adult treated by a right extended hepatectomy along with a literature review.

[Morbimortalidad de la pancreatoduodenectomía en pacientes con cáncer de páncreas y tumores periampulares en el Hospital de Oncología del Centro Médico Nacional Siglo XXI de 2008 a 2013]. / Morbimortality of pancreatoduenectomy in patients with cancer of pancreas and periampular tumors in the Oncology Hospital of Centro Médico Nacional Siglo XXI from 2008 to 2013.

INTRODUCTION: Pancreatic tumors and periampullary tumors have a similar clinical presentation; pancreatoduodenectomy represents the only possibility of cure or of increasing survival; with an average mortality of 5-10% and a morbidity of 20-40%. OBJECTIVE: To determine the morbidity and mortality secondary to the pancreatoduodenectomy intervention in patients with pancreatic cancer or periampullary tumors in the Oncology Hospital of Centro Médico Nacional Siglo XXI (Mexico City) from 2008 to 2013. METHOD: Historical, observational and descriptive cohort carried out in the department of sarcomas and tumors of the upper digestive tube of the Oncology Hospital of Centro Médico Nacional Siglo XXI, postoperative pancreatoduodenectomy from 2008 to 2013. RESULTS: We included 71 patients who underwent pancreatoduodenectomy, 47 (66.2%) were female and 24 (33.8%) were male. The average age was 60.3 years. The most common histology was cancer of the Vater's ampulla (66.2%). The resections were R0 in 95.8% of the cases. Mortality was 4.22% and morbidity was 69%. The most frequent complication was pancreatic fistula (23.9%). In the statistical analysis, perioperative transfusion was associated with surgical complications (p < 0.007). CONCLUSIONS: The morbidity of pancreatoduodenectomy is greater than that reported in the literature, however, it does not influence mortality that is similar to that reported in other centers. The number of lymph nodes resected; as well as the percentage of negative margins are those accepted worldwide; It is concluded that this is derived from the experience of the center where these procedures are performed. No factor with statistical significance was found, only the transfusion that increased the complications.

INTRODUCCIÓN: Los tumores de páncreas y los tumores periampulares tienen una presentación clínica similar. La pancreatoduodenectomía representa la única posibilidad de curación o de aumentar la sobrevida, con una mortalidad promedio del 5-10% y una morbilidad del 20-40%. OBJETIVO: Determinar la morbilidad y la mortalidad secundarias a la intervención de pancreatoduodenectomía en pacientes con cáncer de páncreas o tumores periampulares en el Hospital de Oncología del Centro Médico Nacional SXXI de 2008 a 2013. MÉTODO: Cohorte histórica, observacional y descriptiva, realizada en el departamento de sarcomas y tumores de tubo digestivo alto del Hospital de Oncología del Centro Médico Nacional Siglo XXI, operados de pancreatoduodenectomía entre 2008 y 2013. RESULTADOS: Se incluyeron 71 pacientes que se sometieron a pancreatoduodenectomía; 47 (66.2%) eran de sexo femenino y 24 (33.8%) de sexo masculino. La edad promedio fue de 60.3 años. La histología más común fue cáncer de ámpula de Vater (66.2%). Las resecciones fueron R0 en el 95.8% de los casos. La mortalidad fue del 4.22% y la morbilidad fue del 69%. La complicación más frecuente fue la fístula pancreática (23.9%). En el análisis estadístico, la transfusión perioperatoria se asoció a complicaciones quirúrgicas (p < 0.007). CONCLUSIONES: La morbilidad de la pancreatoduodenectomía es mayor que lo reportado en la literatura; sin embargo, no influye en la mortalidad, que es similar a lo reportado en otros centros. El número de ganglios resecados, así como el porcentaje de márgenes negativos, son los aceptados internacionalmente. Se concluye que esto se deriva de la experiencia del centro donde se realizan estos procedimientos. No se encontró ningún factor con relevancia estadística, excepto la transfusión, que incrementaba las complicaciones.

Retrospective cohort of pancreatic and Vater ampullary adenocarcinoma from a reference center in Mexico.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) and ampulla of Vater adenocarcinomas (AVAC) are periampullary tumors. These tumors have overlapping symptoms and a common treatment, but present differences in their survival and biology. No recent studies in Mexico have been published that describe the clinicopathological characteristics of these tumors. Therefore, the aim of this study was to describe the clinicopathological characteristics of PDAC and AVAC in patients at a reference center in Mexico. METHODS: A retrospective cohort of patients with PDAC or AVAC was analyzed at our institution (July 2007 to June 2016). Inferential analysis of the clinical data was performed with Student's t-test or a χ2 test with odds ratios (OR) and confidence intervals (CI), depending on the variables. Overall survival was compared using Kaplan-Meier curves with log-rank p values. RESULTS: Forty patients with PDAC and 76 with AVAC were analyzed, including 77 females and 39 males with a mean age of 60.6 years and a mean evolution time of 5.7 months. PDAC patients had more abdominal pain, a larger tumor size and more advanced stages than AVAC patients. In contrast, AVAC patients had more jaundice, a higher percentage of complete resections and higher overall survival. Up to 70% of patients were overweight. PDAC cohort included a higher proportion of smokers. CONCLUSIONS: Our cohort was slightly younger, had a larger percentage of females, and a greater percentage of obese patients than those in many international reports. A high proportion of PDAC patients are diagnosed in advanced stages and have a low likelihood of resectability.

Molecular Characterization of the Human Stomach Microbiota in Gastric Cancer Patients.

Helicobacter pylori (Hp) is the primary cause of gastric cancer but we know little of its relative abundance and other microbes in the stomach, especially at the time of gastric cancer diagnosis. Here we characterized the taxonomic and derived functional profiles of gastric microbiota in two different sets of gastric cancer patients, and compared them with microbial profiles in other body sites. Paired non-malignant and tumor tissues were sampled from 160 gastric cancer patients with 80 from China and 80 from Mexico. The 16S rRNA gene V3-V4 region was sequenced using MiSeq platform for taxonomic profiles. PICRUSt was used to predict functional profiles. Human Microbiome Project was used for comparison. We showed that Hp is the most abundant member of gastric microbiota in both Chinese and Mexican samples (51 and 24%, respectively), followed by oral-associated bacteria. Taxonomic (phylum-level) profiles of stomach microbiota resembled oral microbiota, especially when the Helicobacter reads were removed. The functional profiles of stomach microbiota, however, were distinct from those found in other body sites and had higher inter-subject dissimilarity. Gastric microbiota composition did not differ by Hp colonization status or stomach anatomic sites, but did differ between paired non-malignant and tumor tissues in either Chinese or Mexican samples. Our study showed that Hp is the dominant member of the non-malignant gastric tissue microbiota in many gastric cancer patients. Our results provide insights on the gastric microbiota composition and function in gastric cancer patients, which may have important clinical implications.

Circulating blood levels of IL-6, IFN-γ, and IL-10 as potential diagnostic biomarkers in gastric cancer: a controlled study.

BACKGROUND: Gastric adenocarcinoma is the third most common cause of cancer-associated death worldwide. Helicobacter pylori infection activates a signaling cascade that induces production of cytokines and chemokines involved in the chronic inflammatory response that drives carcinogenesis. We evaluated circulating cytokines and chemokines as potential diagnostic biomarkers for gastric cancer. METHODS: We included 201 healthy controls and 162 patients with distal gastric cancer who underwent primary surgical resection between 2009 and 2012 in Mexico City. The clinical and pathological data of patients were recorded by questionnaire, and the cancer subtype was classified as intestinal or diffuse. Pathological staging of cancer was based on the tumor-node-metastasis staging system of the International Union Against Cancer. Concentrations of IL-1ß, IL-6, TNF-α, IL-10, and MCP-1 in serum were measured using multiplex analyte profiling technology and concentrations of IL-8, IFN-γ, and TGF-ß in plasma were measured using enzyme-linked immunosorbent assay. RESULTS: Levels of IL-1ß, IL-6, IFN-γ, and IL-10 were significantly higher and that of MCP-1 was lower in gastric cancer patients compared with controls. No differences in IL-8 or TNF-α levels were observed between gastric cancer and controls. IFN-γ and IL-10 were significantly higher in both intestinal and diffuse gastric cancer, whereas IL-1ß and IL-6 were higher and TGF-ß lower only in intestinal gastric cancer; MCP-1 was lower only in diffuse gastric cancer. IFN-γ and IL-10 levels were significantly higher in early (I/II) and late stage (III/IV) gastric cancer; IL-1ß and IL-8 were higher and MCP-1 was lower only in late stage (IV) patients. Receiver-operating characteristic analysis showed that for diagnosis of GC, IL-6 had high specificity (0.97) and low sensitivity (0.39), IL-10 had moderate specificity (0.82) and low sensitivity (0.48), and IL-1ß and IFN-γ showed low specificity (0.43 and 0.53, respectively) and moderate sensitivity (0.76 and 0.71, respectively). CONCLUSIONS: Increased levels of IL-6, IFN-γ, and IL-10 might be useful as diagnostic biomarkers for GC; however, this needs to be confirmed with larger number of patients and with control groups other than blood donors, properly age paired. IL-1ß, IL-6, MCP-1, and TGF-ß differentiate intestinal from diffuse GC. IFN-γ and IL-10 might be useful for diagnosis of early stage GC, and IL-1ß, IL-8, and MCP-1 for late stages of the disease.

[Immunohistochemical assessment of HER2 expression in gastric cancer. A clinicopathologic study of 93 cases]. / Evaluación por inmunohistoquímica de la expresión del HER2 en cáncer gástrico. Estudio clínico-patológico de 93 casos.

BACKGROUND: Gastric cancer in Mexico is ranked third in both males and females. Most patients present clinically with advanced disease and treatment options are sparse. HER2 overexpression in gastric cancer is related to poor outcome. Immunohistochemical testing for HER2 is becoming the standard of care for guiding adjuvant treatment of gastric cancer with trastuzumab. OBJECTIVES: To determine the frequency of HER2 overexpression in patients with gastric cancer in the Hospital de Oncología del Centro Médico Nacional, Siglo XXI and its association with other histopathological findings. MATERIAL AND METHODS: Patients with gastric cancer who underwent surgery between March 12, 2006-August 31, 2011, were enrolled in this retrospective study. Diagnosis was confirmed by review of slides and immunohistochemistry with anti-HER2 antibody was performed. Scoring was done by Hoffman scoring system. Medical records were evaluated. RESULTS: Ninety-three patients were included in the study, with 43 (46.2%) male and 50 (53.7%) female patients. The median age was 64 years. HER2-positive tumours were identified in 6 patients (6.45%) and located most frequently in the proximal stomach. There was no difference in HER2 overexpression in relation to age, gender or histologic type. CONCLUSION: In our study, about 7% of patients with gastric cancer were HER2-positive on immunohistochemistry.

Polymorphisms in HLA-DQ genes, together with age, sex, and Helicobacter pylori infection, as potential biomarkers for the early diagnosis of gastric cancer.

BACKGROUND: Polymorphisms in inflammation-related genes are factors associated with the development of gastroduodenal diseases in Helicobacter pylori-infected individuals. MATERIALS AND METHODS: We aimed to analyze polymorphisms in HLA-DQ, together with other host and H. pylori variables as risk factors for precancerous and cancerous gastric lesions. 1052 individuals were studied, including nonatrophic gastritis (NAG), intestinal metaplasia (IM), gastric cancer (GC) or duodenal ulcer (DU) patients, and healthy volunteers. RESULTS: Patients with alleles DQA*01:01 (OR 0.78), *01:02 (OR 0.29), *01:03 (OR 0.31), and DQB*02:01/02 (OR 0.40) showed a reduced risk for GC. A multivariate logistic regression analyses showed that patients with homozygote genotypes DQA1*03:01 (OR 7.27) and DQA1*04:01 (OR 8.99) and DQB1*05:01:01 (OR 12.04) were at significantly increased risk for GC. Multivariate analyses also demonstrated that age (OR>10.0) and gender (OR>2.0) were variables that influenced significantly the risk for GC, while H. pylori infection (OR>2.5) increased the risk for IM. CONCLUSIONS: We identified HLA-DQ alleles associated with IM and GC, and confirm that age, sex, and H. pylori infection are variables that also influence the risk for disease. The use of multiple markers, HLA-DQ alleles, age, sex, and H. pylori infection may be useful biomarkers for the early diagnosis of patients with IM and GC.

[Prognostic factors for survival in patients with resectable advanced gastric adenocarcinoma]. / Factores pronóstico de sobrevida en adenocarcinoma gástrico avanzado resecable.

BACKGROUND: Patients under 45 years with gastric cancer are associated with a poor prognosis. Recent studies report that the 5-year survival is better in younger patients after curative resection. OBJECTIVE: To determine if prognostic factors such as age under 45 years old, anaemia, weight loss, tumour differentiation, histological sub-type, depth of invasion, and lymph node involvement, reduce the survival of patients with resectable advanced gastric adenocarcinoma undergoing gastrectomy with limited and extended lymphadenectomy. MATERIALS AND METHODS: This study included a cohort of consecutive cases treated in the Sarcomas Department of the Oncology Hospital of the Centro Médico Nacional Siglo XXI, of the Instituto Mexicano del Seguro Social, during the period between January 2000 and December 2006. RESULTS: Of the total of 588 patients evaluated, 112 (19%) were under 45 years, 43% classified as Borrmann IV, and 36% as Borrmann III. Metastatic disease was present in 39.3%, localised diffuse in 12.5%; lower resectability 52.7 vs. 61.3% in older than 45 years. At the end of the study 29.5% of patients under 45 years were alive; no recurrence in 26.8%, with an overall survival of 58.6±4.3 months, compared with 18.3% of patients alive over 45 years, 17.9% disease-free, and with overall survival 35.2±4.3 months resectable disease. CONCLUSIONS: Patients under 45 years have a better survival after a two-year disease-free period.

Stomach microbiota composition varies between patients with non-atrophic gastritis and patients with intestinal type of gastric cancer.

We aimed to characterize microbiota of the gastric mucosa as it progress to intestinal type of cancer. Study included five patients each of non-atrophic gastritis (NAG), intestinal metaplasia (IM) and intestinal-type gastric cancer (GC). Gastric tissue was obtained and DNA extracted for microbiota analyses using the microarray G3 PhyloChip. Bacterial diversity ranged from 8 to 57, and steadily decreased from NAG to IM to GC (p = 0.004). A significant microbiota difference was observed between NAG and GC based on Unifrac-presence/absence and weighted-Unifrac-abundance metrics of 283 taxa (p < 0.05). HC-AN analyses based on presence/absence of 238 taxa revealed that GC and NAG grouped apart, whereas IM overlapped with both. An ordinated analyses based on weighted-Unifrac distance given abundance of 44 taxa showing significance across categories revealed significant microbiota separation between NAG and GC. This study is the first to show a gradual shift in gastric microbiota profile from NAG to IM to GC.

[Surgical prognostic factors of gastroenteropancreatic neuroendocrine tumors (GEP NET)]. / Tumor neuroendocrino gastroenteropancreático. Factores pronósticos quirúrgicos.

OBJECTIVE: to determine surgical prognostic variables from a retrospective cohort of histopathologically confirmed gastroenteropancreatic neuroendocrine tumors (GEP-NET) in Mexican subjects. METHODS: consecutive patients treated for GEP-NET from 1999 through 2007 at Oncological Hospital were included. Demographic, clinical variables, disease-free survival were retrieved. RESULTS: forty-eight patients were included, 29 (60.4 %) female with a mean age of 54 years. Overall survival time was 43.7 months and disease-free survival was 33 months. Negative statistically significant overall survival time predictors were 2 and 3 histological types (HR 5.5. CI 2.0-21, p = 0.0001), tumor size > 2 cm (HR 8.8, CI 1 .29-75, p = 0.002), the presence of metastasis (HR 2.4, CI 1.2-9.6, p = 0.0001) and tumor resectability (HR 9.8, CI 2.9-40.2, p = 0.0001). For the disease-free period, only the histological type (2 or 3) was a negative outcome variable. CONCLUSIONS: histological type, tumor size, the presence of metastasis, and tumor non resectability were significant survival predictors.

Resectability of primary gastroenteropancreatic neuroendocrine tumor as a prognostic factor for survival.

BACKGROUND: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) originate from gastrointestinal cells and pancreas; most are benign or well-differentiated. GEP-NET treatment objectives are tumor resection and reduction of tumor growth and dissemination, as well as symptom amelioration. We undertook this study to identify prognostic factors among patients with GEP-NETs. METHODS: A total of 48 patients with histopathological diagnosis of GEP-NET were examined. Dependent variables were disease-free survival (DFS) and overall survival rates. Independent variables were age, gender, primary tumor size, resectability, metastatic disease, and histological degree. RESULTS: In 48 patients (60.4% female, 39.6% male, median age 54 years), overall survival rate was 43.7%, and DFS was 33 months. The most common location was gastric. Factors related with the poorest prognosis were histological degree types 2 and 3, tumors >2 cm, metastatic disease, and primary tumor irresectability. For DFS, the only adverse factor was histological degree. CONCLUSIONS: Patients with recurrence of GEP-NET had a poorer prognosis. Complete resection of the lesion with negative margins is the most determining prognostic factor for overrall survival in patients with GEP-NET.

[Gastrointestinal stromal tumors in the pediatric population. Report of two cases and a review of the literature]. / Tumores estromales del tracto gastrointestinal en población pediátrica. Informe de dos casos y revisión de la literatura.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal tumors of the gastrointestinal (GI) tract that occur predominantly in adults. GISTs in pediatric patients are rare and not well characterized. We reviewed the presentation, diagnostic work-up, pathological specimens, and outcomes of two children with GIST that originated from the stomach. Literature pertaining to pediatric GISTs was also reviewed. CLINICAL CASES: Both patients presented with upper GI bleeding from a gastric tumor. The first patient was a 10-year-old male who underwent partial gastrectomy but had recurrence 26 years later requiring surgical exploration due to extensive infiltration into the surrounding organs; the tumor was not resected. The patient is currently being treated with imatinib mesylate. The second patient was a 12-year-old female who had a pedunculated mass originating from the stomach and requiring resection. She subsequently had a local recurrence 2 years later requiring partial gastrectomy. Adjuvant imatinib mesylate was recommended because of the large size of the tumor (8 cm). CONCLUSIONS: Pediatric GISTs represent a distinct subset of sarcomas with a strong predominance for females and gastric location, with 56 cases reported in the English-language literature.

Tumores estromales del tracto gastrointestinal en población pediátrica: informe de dos casos y revisión de la literatura / Gastrointestinal stromal tumors in the pediatric population: report of two cases and a review of the literature

Introducción: El tumor estromal del tracto gastrointestinal es una neoplasia rara que se presentan por lo general en la quinta a séptima década de la vida; en pacientes pediátricos es menos frecuente que en adultos y no está bien caracterizado. En esta descripción se evalúa presentación, diagnóstico clínicopatológico y evolución de dos niños con tumor estromal del tracto gastrointestinal originado en el estómago; también se revisa la literatura respecto a la experiencia mundial que se tiene con este tipo de tumor en la población pediátrica. Casos clínicos: Ambos pacientes iniciaron con hematemesis debido a un tumor gástrico. El primer paciente tenía 10 años de edad cuando se le practicó gastrectomía parcial; después de 26 años experimentó recurrencia local de la enfermedad, por lo que se le practicó laparotomía exploradora que mostró neoplasia con extensa infiltración a órganos vecinos. La neoplasia fue irresecable; se prescribió tratamiento con mesilato de imatinib. El segundo caso correspondió a una niña quien a los 12 años de edad presentó una masa unida a la pared gástrica por un pedículo, la cual fue resecada. Dos años después por recurrencia local se le practicó gastrectomía parcial. Se recomendó mesilato de imatinib como tratamiento adyuvante debido a que el tumor tenía 8 cm de diámetro mayor. Conclusiones: El tumor estromal del tracto gastrointestinal de presentación en la edad pediátrica representa un subgrupo distintivo de sarcomas que predomina en niñas y que por lo general afecta el estómago. En una revisión de la literatura solo se encontraron 56 casos de dicha neoplasia. El pronóstico es variable y heterogéneo. La resección completa de la neoplasia es indispensable y el tratamiento adyuvante con mesilato de imatinib se recomienda para los casos con alto riesgo.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal tumors of the gastrointestinal (GI) tract that occur predominantly in adults. GISTs in pediatric patients are rare and not well characterized. We reviewed the presentation, diagnostic work-up, pathological specimens, and outcomes of two children with GIST that originated from the stomach. Literature pertaining to pediatric GISTs was also reviewed. CLINICAL CASES: Both patients presented with upper GI bleeding from a gastric tumor. The first patient was a 10-year-old male who underwent partial gastrectomy but had recurrence 26 years later requiring surgical exploration due to extensive infiltration into the surrounding organs; the tumor was not resected. The patient is currently being treated with imatinib mesylate. The second patient was a 12-year-old female who had a pedunculated mass originating from the stomach and requiring resection. She subsequently had a local recurrence 2 years later requiring partial gastrectomy. Adjuvant imatinib mesylate was recommended because of the large size of the tumor (8 cm). CONCLUSIONS: Pediatric GISTs represent a distinct subset of sarcomas with a strong predominance for females and gastric location, with 56 cases reported in the English-language literature.