Carcinomas of the renal pelvis, ureters, and urinary bladder arise by similar carcinogenic pathways: A pathoepidemiological analysis.

Abstract

403 Background: Urothelial carcinomas comprise the most common malignant tumors in the urinary tract. Kidney epithelial cancers, on the other hand, have a different pathoepidemiologic incidence and characteristics. We report a population-based analysis of the histopathology of upper and lower urinary tract cancers as an approach to exploring the relationship of tumors that share similar morphologic phenotypes. Our results depend on observations made 65 years ago that age of diagnosis and age specific incidence rates generated straight lines when plotted as logarithms. Methods: Data from 2000 through 2014 from the SEER Program were used to calculate incidence rates of renal, renal pelvis, ureter and urinary bladder cancers. Graphic plots of the epidemiologic patterns were analyzed relating to incidence and age-specific rates of these upper and lower tract carcinomas. The graphic analysis included evaluation of age frequency density plots and double logarithmic plots (log-log) of age-specific incidence rates and age at diagnosis. Results: Cancers of the kidney are initially more frequent than cancers of the urinary bladder, but after age 60, cancers of the bladder become more common with age-specific rates rapidly rising in all age groups. The age frequency density plot for renal cancers peaks earlier, around age 60, indicating a potentially different tumorigenic process. While the log-log plots reveal near parallel proportional rate patterns for cancers of the renal pelvis, ureters, and urinary bladder, while the rate for the cancer of the kidney was not parallel on inspection. Similar slopes indicate that cancer incidence is increasing at near similar rates regardless of the incidence of each cancer. Thus, the percentage change per unit time for cancers of the renal pelvis, ureters, and bladder is comparable. Conclusions: Tumors that arise from the renal pelvis, ureters, and urinary bladder are pathogenically related and share a common carcinogenic field based on pathoepidemiologic analyses.