Treatment of disseminated malignant melanoma with high-dose oral BCG

Abstract

Thirty patients with unresectable disseminated melanoma (Stage IV) were treated with Bacillus Calmette-Guerin (BCG) (Moreau strain--Rio de Janeiro) by mouth, with weekly doses ranging between 200 mg and 28,000 mg. Five patients died in the first two months of treatment. Of the remaining 25 patients, two (8%) showed complete regression, and one (4%) partial regression. Seven patients (28%) had stabilization of the disease for a six-month period, and 15 (60%) had progression of the disease. Complete and partial regressions were seen only in patients with extravisceral (subcutaneous) metastases, and were associated with a longer survival time. Regression of the subcutaneous metastatic nodules was always accompanied by the following local phenomena: increased temperature; local inflammation; softening, pain and pruritus at the nodule site; and a gradual decrease in size. At the site of the tumor mass, a hypochromic halo appeared. This halo remained permanently and was pathognomonic of the metastatic nodule rejection. When the halo was fully established, the inflammatory infiltrate was minimal and the malignant cells disappeared. If the area contained hairs, they underwent complete albinization. Serial biopsies of the nodules undergoing inflammatory changes and decreased consistency exhibited an intense cellular infiltration of lymphocytes, macrophages, and plasma cells around the malignant cells. This sometimes simulated lymphoid follicle formation involving the melanoma cells associated with necrosis in a centripetal way. Some patients with visceral metastases (particularly pulmonary) had an unexpectedly long survival, apparently associated with interruption of the growth rate of the masses. Eleven out of 20 deaths were due to cerebral metastases. When cerebral disease was diagnosed, BCG was discontinued and the administration of corticoids was usually associated with a disappearance of the inflammatory signs at the nodule sites, but with progression of the disease. Toxicity was minimal.