Failure of immunotherapy with neuraminidase-treated tumor cell vaccine in mice bearing established 3-methylcholanthrene-induced sarcomas.

C3H/HeJ mice bearing MC-80 fibrosarcomas were given immunotherapy consisting of multiple injections of a Vibrio cholerae neuraminidase (VCN)-treated tumor cell vaccine at a site remote from the established tumor. In five separate experiments we were unable to show either partial or complete tumor regression or prolongation of survival for vaccine-treated mice compared to appropriate controls. Further, the use of BCG in addition to VCN-treated tumor cells failed to show any therapeutic efficacy. We could not confirm the successful immunotherapy results reported by others despite multiple efforts of reproduce the immunotherapy model as carefully and precisely as possible.