gastric cancer in people below and above 40 is it different?

abstract   background: gastric cancer is the second most common cancer and also the second cancer related death all over the world. in recent years recorded data for tumor has shown a rise in the incidence of gastric cancer in young individuals. the present study was designed to compare some of the epidemiologic characteristics of individuals suffering from gastric cancer aged below and above forty years.   methods: this cross-sectional study was performed on 389 patients suffering from gastric cancer referred to a referral private clinic in tehran during the years 1991 and 2001. the patients were divided into two groups, those older than 40 years and the younger ones. the demographic information, the tumor type and location as well as the prevalence of the h. pylori infection was compared in the two groups. the collected data were entered in spss version 13 and analyzed using chi-square and fisher exact test.   results: fifty patients (12.9%) were reported to be lower than 40 years. the mean age of the patients in this group was 32.1±6.8years while the number was calculated to be 63.23 ± 9.7 years in the other group. the male to female ratio in the group younger and older than 40 years was 1.9: 1 and 2.6:1, respectively. adenocarcinama and lymphoma compromised 70% and 12% of the individuals younger than 40 years whereas they were reported in 89.3% and 3.2% of the patients in the other group. while cancer in the middle third of stomach was the most frequent type in both groups, the prevalence of upper third gastric cancer was considerably higher in those younger than 40 years old (19.9% vs. 5%). h. pylori infection was seen in 23.2% of the younger group, while more than 56% of the older group suffered from h. pylori infection. there was a statistically significant difference between the two groups (p< 0.017).   conclusion: gastric cancer is not rare among the individuals younger than 40 years old. the disease is reported to be seen in the absence of h. pylori infection in the majority of these cases. there is a considerable difference between the prevalence of malignant lymphoma in this group of patients compared with the older patients.