Carcinomas of the Renal Pelvis, Ureters, and Urinary Bladder Share a Carcinogenic Field as Revealed in Epidemiological Analysis of Tumor Registry Data.

BACKGROUND: Urothelial carcinomas are the most common malignant tumors in the upper and lower urinary tract. Renal cell carcinomas (RCCs) have a different pathoepidemiologic incidence and characteristics. We describe a population-based approach of differentiating between urothelial and renal carcinomas as a basis to support shared morphologic phenotypes.

MATERIALS AND METHODS: Data from 2000 through 2014 from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute were used to calculate the incidence rates for cancers of the kidney, renal pelvis, ureter, and urinary bladder. Graphic plots of the epidemiologic patterns were analyzed according to age frequency density and double logarithmic (log-log) plots of age-specific incidence rates and age of diagnosis.

RESULTS: RCCs were initially more common than cancers of the urinary bladder, but after age 60, cancers of the bladder became more common with age-specific rates rapidly rising in all age groups. The age frequency density plot for RCC peaked earlier than for urothelial cancers indicating a different tumorigenic process. Log-log plots revealed near parallel proportional rate patterns for cancers of the renal pelvis, ureters, and urinary bladder, suggesting similar carcinogenic pathways among these tumors, whereas they were not parallel for RCCs. Similar slopes indicate that cancer incidence is increasing at similar rates regardless of the incidence of each cancer.

CONCLUSION: Tumors that arise in the renal pelvis, ureters, and urinary bladder share a common carcinogenic field on the basis of pathoepidemiologic analysis. The definition of a carcinogenic field should expand to include epidemiological parameters as well as common morphologic and embryological patterns.