Immunotherapy of postoperative metastases of 13762A rat mammary adenocarcinoma: comparative effectiveness of BCG substrains and methods of preparation.

Six Bacillus Calmette-Guérin (BCG) substrains (Phipps, Pasteur, Connaught, Glaxo, RIV, and Tice) and two methods of preparation and storage (pellicle-lyophilized, dispersed-frozen and dispersed lyophilized) were directly compared in a standard immunotherapy protocol. Complete Freund's adjuvant and Bordetella pertussis vaccine were also studied. All experiments included direct comparisons with Corynebacterium parvum. The immunotherapy assay system was the 13762A rat mammary carcinoma in which immunity stimulant were given intratumorally on day 7, followed by excision of primary tumors on day 20. In this protocol, C parvum produced strong inhibition of established metastases and some cures. All of the BCG strains except Glaxo were effective in at least one experiment but none was as strong or as consistent in its effects as C parvum. No strain of BCG or method of preparation was clearly superior to the others. The B pertussis vaccine and complete Freund's adjuvant were ineffective.