The etiology of renal-cell carcinoma.

Experimental renal-cell carcinoma can be induced by many different chemical carcinogens; dimethyl nitrosoamine has been most studied. The disease so induced in experimental animals closely resembles the spontaneous disease in man in histopathology, course, and other characteristics. Two agents that are probably etiological of renal-cell cancer in man are tobacco and the analgesic, phenacetin; however, these materials can account for only a minority of the cases. The predominance of males in adult renal carcinoma might be explained by the more efficient metabolic activation of carcinogens by renal enzymes that are induced by male hormones. Mouse experiments support this hypothesis. Studies utilizing human kidney tissues that would test the hypothesis in man can and should be done. No obvious clues have emerged to explain the wide geographic differences in incidence of renal carcinoma. No group of industrial workers, or of others with a unique environment, has yet been described that has an especially high incidence of renal-cell carcinoma. A minority of renal carcinomas are familial. They represent a number of different diseases, one of which is associated with the von Hippel-Lindau disease. The hereditary renal-cell carcinoma of the Ecker rat, which is transmitted as an autosomal dominant, provides a useful laboratory model for hereditary carcinoma of man. Recently, two human families with renal-cell carcinoma were described in which there were unique chromosomal abnormalities associated with the disease. Such changes have been linked with oncogene activation in the instance of other tumors. Further studies of chromosomal abnormalities in renal-cell carcinoma will probably define a common pattern of chromosomal rearrangements. While estrogen readily induces renal-cell carcinoma in hamsters other species, including man, appear resistant. An excess of renal-cell carcinoma has not been reported in men on chronic estrogen therapy for prostatic carcinoma, nor has it been associated with the DES syndrome. A virus etiology for renal-cell carcinoma in man comparable to that of the Lucke tumor in frogs is unlikely on epidemiologic, ultrastructural morphologic, and other grounds. There is nothing suggesting horizontal transmission in the human disease, and a unique excess of renal-cell carcinomas in immunosuppressed patients or patients with the acquired immunodeficiency syndrome (AIDS) is not apparent. There is overwhelming evidence that renal adenomas represent early adenocarcinomas, or at least precursor lesions; certainly they are closely related to renal-cell carcinomas.(ABSTRACT TRUNCATED AT 400 WORDS)