Underreporting and misclassification of urinary tract cancer cases on death certificates.

We compared the diagnoses for decreased cases with urinary tract cancer reported to the Surveillance, Epidemiology, and End Results (SEER) program with their underlying cause of death reported on death certificates. Deaths for a substantial proportion of cases were ascribed to noncancer causes (bladder, 48%; kidney, 28%; renal pelvis, 37%; and other urinary tract, 38%), which decreased with advancing stage at diagnosis and increased with length of survival. In general, cancer deaths were more likely to be recorded to the predominant subsite within an organ. Only 5.5% of renal pelvis cancer patients were recorded to have died of their illness, whereas 33.7% of their deaths were reported as due to kidney cancer. On the other hand, over 85% of urinary tract cancer deaths reported on the death certificates were confirmed by SEER diagnosis, although the extent of agreement varied by stage at diagnosis and age at death for kidney and renal pelvis cancers.