Effects of postsurgical immunotherapy with PGM in mice bearing Lewis lung carcinoma treated with p-(3,3-dimethyl-1-triazeno) benzoic acid potassium salt.

The effects of preoperative treatment with dimethyltriazene p-(3,3-dimethyl-1-triazeno) benzoic acid potassium salt (DM-COOK) followed by surgery and non-specific immunotherapy with the peptidoglycan monomer PGM have been evaluated using the Lewis lung carcinoma implanted i.m. in BD2F1 female mice. The survival time of mice treated with this combination is prolonged and the percentage of animals cured is markedly increased as compared with untreated controls or with mice treated with DM-COOK or PGM alone. The synergism between DM-COOK and PGM could be attributed to the capacity of the triazene to render the treated tumor cells more antigenic, combined with the favourable effects of PGM to restore host defense mechanisms. In this combined treatment, the use of cyclophosphamide at dosages having the same activity displayed by PGM alone does not ameliorate the results obtained with DM-COOK alone.