Prospective studies of the general population have isolated specific social and psychological factors as independent predictors of longevity. This study assesses the ability of these factors, plus two others said to influence survival in patients with cancer, to predict survival and the time to relapse after a diagnosis of cancer. Patients with unresectable cancers (n = 204) were followed to determine the length of survival. Patients with Stage I or II melanoma or Stage II breast cancer (n = 155) were followed to determine the time to relapse. Analysis of data on these 359 patients indicates that social and psychological factors individually or in combination do not influence the length of survival or the time to relapse (P less than 0.10). The specific diagnosis (F = 2.0, P = 0.06), performance status (F = 0.66, P = 0.62), extent of disease (F = 1.12, P = 0.89), and therapy (F = 1.08, P = 0.35) were also unrelated to the psychosocial factors studied. Although these factors may contribute to the initiation of morbidity, the biology of the disease appears to predominate and to override the potential influence of life-style and psychosocial variables once the disease process is established.