According to the American Joint Committee on Cancer (AJCC), the number of metastatic lymph nodes is the main prognostic factor in gastric cancer. Lymph node ratio (LNR) has been proposed as a better predictor of survival. We included patients resected for gastric cancer in a referral center in Mexico City. Number of metastatic nodes was analyzed according to AJCC 2002 and 2010. We divided LNR into four stages. Survival was calculated with the Kaplan-Meier method and curves compared with the log-rank test. P < 0.05 was significant. Two hundred patients were included. Median number of retrieved and metastatic nodes were 18 and 2.5, respectively. Median survival was 44 months. AJCC 2010 was a better predictor of survival than the 2002 version ( P < 0.001). Median survival for LNR 0, 1, 2, and 3 was 117, 68, 44, and 14 months, respectively ( P < 0.001). In patients with less than 15 nodes removed, AJCC was not a predictor of survival ( P = 0.09) but LNR was ( P = 0.04). Nodal staging in AJCC 2010 is a better predictor of survival than the 2002 edition. LNR is useful in the group of patients with suboptimal node dissection.

Background: Colorectal cancer is frequent in the developed countries, with a cancer-specific mortality rate of 33%. Different biomarkers are associated with overall survival and the prediction of monoclonal treatment effectiveness. The presence of mutations in the K-ras oncogene alters the response to target therapy with cetuximab and could be an independent prognostic factor. Aims: To analyze the difference in survival between patients with mutated K-ras and those with K-ras wild-type status. Methods: Thirty-one clinical records were retrospectively analyzed of patients presenting with colorectal cancer that underwent K-ras sequencing through real-time polymerase chain reaction within the time frame of 2009 to 2012 at the Hospital de Alta Especialidad de Veracruz of the Instituto para la Salud y Seguridad Social de los Trabajadores del Estado (HAEV-ISSSTE). Survival analysis for patients with and without K-ras mutation was performed using the Kaplan Meier method. Contrast of covariates was performed using logarithmic transformations. Results: No statistically significant difference was found in relation to survival in the patients with mutated K-ras vs. those with K-ras wild-type (P = .416), nor were significant differences found when analyzing the covariants and survival in the patients with mutated K-ras: ECOG scale (P = .221); age (less than, equal to or greater than 65 years, P = .441); clinical stage according to the AJCC (P = .057), and primary lesion site (P = .614).ଝ Please cite this article as: Cabrera-Mendoza F, Gainza-Lagunes S, Castañeda-Andrade I, Castro-Zárate A. Relevancia clínica del oncogén K-ras en cáncer de colon, experiencia en una población mexicana. Revista de Gastroenterología de México. 2014;79:166---170.

Síndrome de intestino irritable posterior a colecistectomía laparoscópica. Estudio de cohorte prospectivo Irritable bowel syndrome posterior to laparoscopic cholecystectomy. A prospective cohort study

No relation was found between the K-ras oncogene mutation and reduced survival, in contrast to what has been established in the international medical literature. Further studies that include both a larger number of patients and those receiving monoclonal treatment, need to be conducted. There were only 5 patients in the present study that received cetuximab, resulting in a misleading analysis.