[81 cancers of the rectosigmoid junction. Colonic or rectal neoplasms?]

With the aim of a better understanding of the cancer of the rectosigmoid junction the authors studied a series of 245 patients treated in Surgery Department 4 with the following distribution according to the localization: 113 in the sigmoid, 81 in the rectosigmoid junction and 51 in the superior rectum. The percentage of cases operated for intestinal obstruction in the rectosigmoid junction (37.0%) was higher than those in the superior rectum (7.8%) (p = 0.001) and the resectability rate of tumours located in the rectosigmoid junction (44.4%) was lower than that of those located in the sigmoid (68.1%) (p = 0.004). In the patients submitted to surgical resection the greater percentage of tumours in stage A and B (58.3%) and with venous invasion (34.4%) was observed in the rectosigmoid junction. Nevertheless, the differences according to the site and shape of the tumour, degree of differentiation, stage and venous invasion were not statistically significant. The 5-year survival rate in 101 cases submitted to resection was higher in patients with tumours in the superior rectum (75.9%) than in patients with carcinomas located in the rectosigmoid junction and in the sigmoid (51.5% and 36.8%, respectively). In summary, this study supported those who consider the rectosigmoid junction cancers as a specific group, based on the particular association of the high frequency of intestinal obstruction and the low resectability rate, apparently related with a special anatomic localization, in a curved segment of the large bowel and suggests that these carcinomas do not constitute, in fact, a colo-rectal independent histopathologic entity.