Résumé
Colorectal carcinoma is the most common malignant disease of the gastrointestinal tract and causes approximately 500000 deaths in the world annually. Previous studies indicated that the epidemiology of this disease in the eastern countries is different from European countries and USA. Therefore we decided to evaluate the incidence of colorectal tumors in the capital city of Tehran, Iran. In this cross-sectional study, we reviewed pathology reports of 144 patients with colorectal tumors between 2004 and 2007. The prevalence of colorectal tumors according to type of tumor [polyp or cancer], age, sex, tumor site and tumor grade were evaluated. Forty-seven and Fifty-three percent of tumors were cancer and polyp, respectively. The most prevalent site for colorectal carcinoma was rectum [41%], followed by sigmoid colon [21%], caecum and ascending colon [18%], and transverse and descending colon [each 10%]. The prevalence of carcinomas of rectum, sigmoid and descending colon were higher in men than women, and cancers of transverse colon, caecum and ascending colon [right colon] were higher in women than men, grade of malignancies were increased from distal colon to proximal colon. In higher ages, the probability of finding malignant tumors was significantly higher than benign tumors. The remarkable prevalence of right colon cancer in this Iranian population showed the importance of colorectal cancer screening, especially total colonoscopy which can be useful for early detection of right colon cancers