Prolongation of postoperative disease-free interval and survival in human colorectal cancer by B.C.G. or B.C.G. plus 5-fluorouracil.

83 patients with colorectal carcinoma of the Dukes' C class were randomised to receive postoperative adjuvant therapy with B.C.G. alone or in combination with oral doses of 5-fluorouracil (5-F.U.), and have been followed for up to thirty months. Results were compared with carefully selected historical controls who were treated by surgery alone. A statistically significant prolongation of both disease-free interval and overall survival was observed in 50 patients receiving the combination of B.C.G. and 5-F.U. (P=0.03, P=0.01 respectively) as well as in 33 patients receiving B.C.G. alone (P=0.03, P=0.05 respectively). The efficacy of B.C.G.+5-F.U. was independent of the number of tumour-involved lymph-nodes in the surgical specimen. In contrast, B.C.G. given alone appears to be highly effective among 10 patients with 6 or more positive lymph-nodes (P less than 0.04) and ineffective (as yet) among 23 patients with 5 or less positive lymph-nodes. These results suggest that adjuvant immunotherapy, with or without chemotherapy, can improve the prognosis of surgically treated patients with colorectal carcinoma of the Dukes' C class.