Impact of discordant radiologic and pathologic tumor size on renal cancer staging

A reduction in kidney tumor size is commonly observed at surgical resection because of a loss of blood flow to the tumor. This tumor size reduction has an impact on the final pathologic stage in organ-confined tumors for which size is the only criterion. The greatest tumor size reduction, and most frequent downstaging, was observed for conventional (clear cell) tumors. We believe this may explain, in part, the worse stage-stratified outcomes for clear cell tumors compared with other tumor types. We propose that renal cancer staging should be determined from accurate measurement of the radiologic size, rather than the pathologic size.