[The use of BCG as immunoadjuvant in combination with antitumor drugs in a virus induced leukemia. II].

Various treatment schedules of BCG with respect to tumor challenge and drug administration were applied in a histocompatible tumor-host system. LSTRA, an ascitic lymphoma induced by Moloney leukemia virus in BALB/c mice, was inoculated ip in histocompatible CD2F1 mice. BCG was administered ip before and/or after (-14, +1, -14+1) the tumor challenge. The drugs used in our experiments: cyclophosphamide (CY), iphosphamide (IPHO), nitrogen mustard (NM), were given at graded doses on day +5. In our experimental system the BCG treatment schedule (-14+1) only showed synergistic antitumor effects at defined doses: only the association BCG-CY have no significant survival percentage increase. No synergistic antitumor activity was evidenced when the drugs were associated with BCG given 14 days before or 1 day after the tumor challenge. The degree of immunochemotherapy treatment efficacy was different according to various antineoplastic agents used. It was never found any treatment schedule was able to cure experimental mice with the best survival percentage increase.