Chemoprophylaxis for patients with colorectal cancer. Prospective study with five-year follow-up.

The effectiveness of a short-term fluorouracil chemopophylaxis regimen commencing four to six weeks after "curative" surgery was evaluated in a homogeneous group of 213 patients with colorectal cancer. In stage III disease (Dukes class C), five-year survival with no evidence of disease (NED) was 24.3% when treated by surgery alone but was 57.5% when a prophylactic regimen of fluorouracil was added (P less than .01), an increase of 33.2%. In stage II disease (Dukes class B), five-year NED survival was raised from 58.5% to 81.6%, an increase of 23.1% (P less than .02). More striking are the one-, two-, and three-year NED survivals in stage III. The one-, two-m and three-year NED survivals for the chemoprophylaxis group are 100%, 95%, and 75%, respectively, in contrast to 70.7%, 48.8%, and 34.1% in the group with surgery alone. The present data indicate that fluorouracil chemoprophylaxis offers a significant improvement of five-year cure rate of patients with stage II and III disease, an overall increase of 28.1% (P less than .01).