Objective To discuss the influence of sex in gastric cancer via the epidemiology and clinical data analysis of gastric cancer patients. Methods The clinical data of 242 gastric cancer patients was collected from Shanxi provincial tumor hospital between 1997 to 1998. Every patient filled in gastric cancer epidemiology form by professional-staff direction, which included personal characteristics, food habits, farmalial history of cancer and other informations. Results The average age of male gastric cancer patients was 6 years older than the females'. Male ulcer type gastric cancer patients were more than the females' (120 vs 38, P < 0.01). There was no different in cell types, differentiation, tumor stage and the clinical pathological features of lymph node metastasis. Male alcoholic drinkers, tea drinkers and smokers were more than the females' . There was no different in sex in tumor familial history and dietary habits of water, well-done food, sour food, vegetables, fruits and amount of radiation of meats, eggs and milk. Conclusion This research reveals the characteristics of sex in the epidemiology of gastric cancer. It is very important and significant not only in the research of gastric cancer etiology, but also in the prevention and intervention of gastric cancer.

Objective To investigate the effect of tumor length and number of positive lymph nodes and the ratio of positive lymph nodes on survival in patients with esophageal squamous cell carcinoma.Methods From July 1995 to July 2005, a total of 6,691 resected lymph nodes were obtained from 526patients who underwent curative resection of the primary tumour with systematic lymphadenectomy. The survivals were analysed by life tables and Kaplan-Meier methods. Results Among patients with regional disease, the number of positive lymph nodes (＞3) was related to an increasing risk. The proportion of positive lymph nodes compared with the number of lymph nodes dissected (20 %) conferred an increased risk. The tumor length (≤5 cm, 5 cm ＜ length ＜ 7 cm, ＞7 cm) was related to an increasing risk (84.74 %, 47.79 %,36.90 %, 35.52 %; 73.41%, 46.29 %, 23.87 %, 20.64 %; 64.44 %, 13.92 %, 0, 0). Conclusion Tumor length,the number of positive lymph nodes, and the ratio of positive lymph nodes are important prognostic factors for survival in patients with esophageal carcinoma. The PTNM classification system for patients with esophageal carcinoma might consider adding number of positive lymph nodes as an important prognostic factor.