COEXISTENCE OF RENAL-CELL CARCINOMA AND MALIGNANT-LYMPHOMA - A CAUSALRELATIONSHIP OR COINCIDENTAL OCCURRENCE

BACKGROUND. Secondary malignant neoplasms are increasingly being obser ved in cancer populations and a considerable amount of data have accum ulated in the literature. Among the secondary malignant neoplasms that occur with a higher incidence in cancer patients are lymphomas and re nal cell carcinoma (RCC), as well as melanoma, lung/bronchus carcinoma . METHODS. The authors analyzed the patient population at the Memorial Sloan-Kettering Cancer Center in New York City between 1985 and 1995 for coexisting carcinomas, and identified 15 patients who had both RCC and malignant lymphoma among a total of 1262 patients with RCC and 16 60 patients with malignant lymphoma. The occurrence and time of diagno sis of both malignant neoplasms and their clinical features, types, an d stages, as well as short term followup results, are presented. RESUL TS. The data show a greater than coincidental coexistence of RCC and m alignant lymphoma (P < 0.01). In addition, there was a significant inc rease in the number of patients with both melanoma and RCC (P < 0.01), as well as melanoma and malignant lymphoma (P < 0.01). No significant increase was found in cases of coexisting RCC or malignant lymphoma w ith either lung/bronchus carcinoma or colorectal carcinoma (P > 0.05). CONCLUSIONS. Causes of this increased coexistence may include a genet ic predisposition to cancer, similar immune mechanisms associated with these neoplasms, closer scrutiny of this group of patients, or a comb ination of these factors. Studies are underway to elucidate a common g enetic component in these patients. (C) 1996 American Cancer Society.