Immunologic studies in patients with malignant melanoma in Uganda.

THE natural history of malignant melanoma in Uganda has been recently studied in a retrospective analysis of 200 cases, and three clinical groups have been delineated (Lewis and Kiryabwire, 1968). Group 1 (40%) consisted of patients with a relatively long history of a localised tumour, usually on the sole of the foot, with no metastases. Group 2 (48%) included patients with a primary lesion with regional or distant metastases and a short clinical history. Group 3 (12%) consisted of patients presenting with metastatic melanoma in whom no primary lesion could be found. There were no distinguishing histological features among the three groups, and the authors suggested that a difference might exist in the host response to this tumour. Lewis (1967) also demonstrated an in vitro cytotoxic effect of autologous serum against melanoma cells of Group 1 but not Group 2 patients, suggesting possible immunological differences. The present study was undertaken to examine the immunologic status in the patient with localised and metastatic malignant melanoma, and to determine if defective immune mechanisms might be related to the occurrence of tumour metastasis. To this end, a study of cellular and humoral immunity in 19 Ugandan patients with malignant melanoma was performed.