Time trends in the incidence of renal carcinoma: analysis of Connecticut Tumor Registry data, 1935-1989.

Recent trends in the incidence of renal cancer, stratified by histology, have not been reported. This study utilized data from the Connecticut Tumor Registry (CTR), the oldest population-based cancer registry in the United States, to establish time trends in the incidence of adenocarcinoma and transitional cell carcinoma of the kidney and urinary tract. All 10,209 incident cases of renal cancer reported to the CTR between 1935 and 1989 were analyzed. Regression modelling was employed to determine the effects of age, period, and birth cohort on incidence rates, and to project future trends. The incidence rate of adenocarcinoma increased in females from 0.7/100,000 in 1935-39, to 4.2/100,000 in 1985-89; and in males, from 1.6/100,000 in 1935-39, to 9.6/100,000 in 1985-89. The reported incidence of transitional cell carcinoma increased in males from 0.5/100,000 in 1950-54 to 2.8/100,000 in 1985-89, and in females from 0.2/100,000 to 1.1/100,000 over the same period. Regression modelling revealed that both net and recent drift, the sum of period and cohort slopes, were positive for adenocarcinoma in both sexes, largely due to a positive cohort effect. While the net drift for transitional cell carcinoma was positive, recent drift was negative in both sexes due primarily to a negative cohort effect. Incidence rates of adenocarcinoma are likely to rise in the immediate future, with the rate of rise in females possibly exceeding that in males. Incidence rates of transitional cell carcinoma will stabilize.