Colorectal cancer is a common and lethal disease, influenced by genetic and environmental factors and the interaction between both. The risk of colorectal cancer is strongly associated with the number and age of first degree relatives with colorectal cancer. Methods: A retrospective study was performed having as its objective all the patients submitted to colonoscopy in a reference hospital in the city of Porto Alegre, between 2003 and 2007. The goal is to study the prevalence of adenomas in patients with family history of colorectal cancer. Results: From the 2,462 analyzed patients, 118 had family history for colorectal cancer and 2,344 did not have. In both groups there was predominance of females (P=0.001). In the patients with adenomas and family history of colorectal cancer, there was predominance of females. In the patients with no family history of colorectal cancer there was predominance of males (P=0.032). The number of adenomas between them was not statistically significant (P=0.187). Conclusion: The group with family history of colorectal cancer has shown more women (P=0.001) and the age was also lower (P=0.002). The comparison between the group with adenomas and family history for colorectal cancer has shown a bigger number of women than the group with adenomas with no family history for colorectal cancer (P=0.032).
