Forty-five immunocompetent patients with solid
tumors were immunized with BCG,
PPD, and
tumor cells. The methods were practical, but the morbidity was significant, including painful draining ulcerations at
vaccine sites, possible enhancement of
tumor growth in three patients, and the discovery at autopsy of systemic
tuberculosis in one patient. Various facets of cellular immunity were altered, namely: 1) a majority of the patients developed enhanced cutaneous reactions to the microbial skin-test
antigens (particularly
tuberculin) and
tumor cells; 2) nine patients developed the equivalent of
delayed hypersensitivity reactions or flares at all previous
PPD and BCG inoculation sites following subsequent injection of these agents, which supports the concept of immunologic memory for these target
antigens; 3) lesions resembling those of "spontaneous" regressed moles (
halo-nevi) were observed at previous
vaccine sites in 20 patients and generalized depigmentation occurred in three patients; 4) foreign body giant cells in
tumor metastasis remote from BCG-
PPD-
tumor vaccine sites may indicate a cross-reactivity of microbial and
tumor antigens; and 5) intralesional inoculation of the nonspecific agents (BCG,
PPD,
Varidase, and
Mumps) resulted in dense mononuclear cell infiltration and complete regression of most of the injected lesions. Destruction of single or multiple lesions by local
injections of
antigens did not provide either significant regression of uninjected lesions or clinical benefit.