Regression of a hamster melanoma with intralesional Corynebacterium granulosum.

The present study was undertaken to compare the antitumour effects of intralesionally administered Corynebacterium granulosum, Corynebacterium parvum, BCG and saline on a hamster melanoma. Forty-eight golden hamsters were inoculated subcutaneously with Forthers melanotic melanoma no. 1. Twenty-four animals bore palpable tumours which were excised. No non-excised group animal showed primary tumour regression. In the excised group, the tumours generally recurred at the excision site in the C. parvum, BCG and saline-treated animals. By contrast, the incidence of recurrence was significantly reduced by intralesional injections of C. granulosum.