Increasing Incidence of Renal Cell Cancer—Reply

In Reply: The finding by Drs Katner and Baynham of a higher prevalence of renal cell carcinoma among HIV-positive vs HIV-negative patients is intriguing and should be evaluated in future epidemiological studies of renal cell cancer. However, we note that an excess risk of kidney cancer has not been reported in population-based studies of HIV-infected persons.^1- 2 Thus, the association between HIV infection and renal cell cancer in a hospital-based series may be spurious, perhaps due to selective referral of patients or extensive medical surveillance of HIV-positive patients. Further information on the clinical stage of the renal tumors, the time sequence of disease events, and the characteristics of the general source population would help in drawing inferences about a possible relation to HIV infection. However, the available incidence and mortality data from the United States indicate that the increase in kidney cancer started many years prior to the AIDS epidemic.³