Immunological Effects of BCG in Malignant Melanoma: Two Modes of Administration Compared

Abstract

A comparison was made of the effects of two modes of administering bacillus Calmette-Guérin (BCG) vaccine on the immunological reactivity of malignant melanoma patients after surgical excision of clinically apparent tumor. A nonspecific potentiating effect on cellular reactivity to both primary and recall antigens was observed in the group receiving BCG by dermal scarification. No such effect was noted in the group receiving intradermal BCG vaccination. This difference might be accounted for by the fact that the administered dose of the former preparation was approximately 1 X 104 times larger than the latter. Although each course of therapy was continued for only 28 days, a significant difference in remission duration is already evident between the two groups (P = 0.01). All intradermally treated patients developed recurrent tumor by 30 weeks, whereas all but one of the scarified patients remain free of tumor at 50 to 59 weeks from the time of surgery.