Comparison of the descriptive epidemiology of urinary tract cancers.

We compared the descriptive epidemiology of several urinary tract cancers, utilizing incidence data from the United States and international sources. The patterns of cancers of the renal pelvis, ureter, and urethra were more similar to those of bladder cancer than to cancer of the renal parenchyma in several ways: (i) transitional cell carcinoma is the predominant histologic type in the renal pelvis, ureter, urethra, and bladder, whereas the vast majority of renal parenchyma neoplasms are adenocarcinomas; (ii) in situ tumors often appear in all these sites except the renal parenchyma; (iii) rate ratios for renal pelvis/ureter cancers among blacks and Hispanics, relative to whites, are closer to those for bladder than to those for renal parenchymal cancers; (iv) rates among US men and women for cancers of the renal pelvis and ureter are more highly correlated with those for bladder cancer than with those of the renal parenchyma across racial groups; and (v) similar correlations occur among women across geographic areas within the US and internationally. However, the patterns for cancers of the renal pelvis and ureter do not always resemble more closely those for bladder than renal parenchyma cancers and occasionally appear different from one another. These findings indicate the importance of distinguishing tumors based on specific primary site and cell type.