Neoplasias colorretais: aspectos epidemiológicos, endoscópicos e anatomopatológicos - estudo de série de casos

Abstract

The colorectal carcinoma (CRC) is the second most frequent cancer in the world population. The high incidence of CRC and the difference in the results of the treatment of cancer, according to the stage of disease justify the efforts for screening, prevention and early detection. The objective of this study was to describe the epidemiological, endoscopic and pathological of polypoid lesions and colorectal cancers and assess the role of colonoscopy in preventing the CRC. This is a descriptive study of number of cases addressed in centre specializing in gastrointestinal endoscopy. In the period January 2002 to December 2006, colonoscopies were performed in 1962 and 1,491 individuals in 492 (33%) of these have been identified polypoid lesions; 408 individuals were considered for analysis. The data were included and analyzed in the Epi Info-2000. In a series of cases studied, 60% of the subjects were asymptomatic. The prevalence of colorectal cancers was 50% (60/120) in men and 42.4% in women (122/288). The cancers were detected on 138 of the 287 individuals (48%) with 50 years or more, and their prevalence was significantly higher than those with less than 50 years (44/121) 36.3% (p = 0.01). It was found that 58.9% of individuals with advanced cancer and cancer had positive family history for cancer of the breast, uterus, ovary, or colorectal. In 408 individuals, 679 colonoscopies were performed, with withdrawal of 959 polypoid lesions; these, 463 (48.3%) were neoplasms, included 13 adenocarcinomas. In lesions smaller than 5 mm, was shown dysplasia in 36% (346/959). In the proximal colon, 21% (85/408) of the subjects had neoplastic lesions in 2% (8 / 408), advanced malignancies, including six cases of adenocarcinoma without any evidence of damage in distal colon. The indication of colonoscopy only by the presence of lesions in the distal colon is controversial. Among the 232 individuals who had neoplastic lesions (benign, or advanced), 130 (56%) had only injuries in proximal colon. If the screening was done only with the retossigmoidoscopy, loss diagnosis of benign neoplastic lesions would be 76 (62.3%) in women and 29 (48.3%) in men. Regarding adenocarcinoma, the loss would be diagnostic of 50% for both sexes. Colorectal neoplasms are common even in asymptomatic subjects. Male, age and family history for cancer are risk factors for the detection of lesions. A colonoscopy is the most effective method of screening for the CRC, indicated for all individuals over 50 years old because, by identifying and removing neoplastic lesions, the colonoscopist have the ability to interfere directly in the natural history of this form of cancer.