At NCC Hospital during 13 year period 1962-1974, 349 patients of carcinoma of the rectum and anal canal were surgically treated.
In these cases we investigated the lymphatic metastases in relation to several pathological characteristics of the primary tumor and its effect on prognosis.
In all cases of this series, lymphatic metastases were found in 51.8 per cent. The location of tumor had not influence on frequency of lymphnode metastasis.
In this study, lymphatic drainage of the rectum was divided into two ways; superior spread and lateral spread. Metastases of lateral pedicle was found in 13.4 per cent of all cases.
Distribution of lymphnode metastases according to location of tumor, relationship of site of tumor to lateral lymphatic spread, and frequency of lymphnode metastases in relation to the depth of invasion and size of tumor were also studied.
Five-year survival rate of all curatively resected cases was 51.5 per cent. Five-year survival rate for cases without lymphatic metastases was 62.5 per cent and this was reduced to 26.8 per cent for those with lymphatic metastases. In Astler's A cases, five-year survival rate was 94.9 per cent, in B₁ cases 88.9 per cent, in B₂ cases 57.6 per cent, in C₁ cases 29.6 per cent, and in C₂ cases 26.7 per cent.