Immune Responses to Human Malignant Melanoma

Abstract

Malignant melanoma has become an important human model of study for the tumor immunologists because clinical and laboratory observations suggested that tumors of this type may be immunogenic and may provoke immune responses in the tumor bearing host. Host control of tumor growth is best illustrated clinically by cases of spontaneous regression of tumors. Spontaneous regression is defined as the complete disappearance or the reduction in size of histologically identified tumor in the absence of therapy that would be considered adequate to alter significantly the natural course of the disease. Well-documented cases of spontaneous regression of melanoma tumors have been described (1,2). Although malignant melanomas represent less than 1% of all human malignancies, they account for 11% of the reported cases of spontaneous regression (3). Approximately 40% of the patients with spontaneous regressions were apparently cured with no recurrence on longterm follow up or at autopsy performed after death from other courses (4). Of the 437 cases of primary cutaneous malignant melanoma studied by McGovern (5), 54 cases showed partial regression histologically.