Life Expectancy of Renal Cell Carcinoma with Variant Histology

The effect of variant histology in renal cell carcinoma (vhRCC) on survival relative to age- and sex-matched population-based controls is unknown. This study aims to analyze the life expectancy of vhRCC patients. In the Surveillance, Epidemiology and End Results (SEER) database (2004-2016), we identified 2928 patients with vhRCC, including mesenchymal, collecting duct, medullary, mucinous, and neuroendocrine RCC, as well as RCC of sarcomatoid and rhabdoid differentiation. Kaplan-Meier plots addressed overall survival relative to simulated life expectancy in population-based controls (Monte Carlo simulation), were derived from the Social Security Administration life tables. Of the 2928 vhRCC patients, 1905 (65%) harbored sarcomatoid, 404 (14%) mesenchymal, 318 (11%) collecting duct, 94 (3%) rhabdoid, 80 (3%) medullary, 68 (2%) mucinous, and 59 (2%) neuroendocrine RCC. Most vhRCC subtypes exhibit regional or metastatic stage at diagnosis, except for mucinous RCC. When diagnosed in metastatic stage, all vhRCC subtypes exhibited a decrease in survival rate ranging from -75% to -98% between controls and cases, except for mucinous and neuroendocrine RCC, with the least decrease in survival rate of -62% and -59%, respectively. In regional stage, all vhRCC subtypes exhibited a decrease in survival rate ranging from -68% to -41% between controls and cases, except for neuroendocrine RCC, with the least decrease in survival rate of -27%. Finally, in localized stage, all vhRCC subtypes exhibited a decrease in survival rate ranging from -56% to -22% between controls and cases, except for rhabdoid and mucinous RCC, with the least decrease in survival rate of -11% and -6%, respectively. Most vhRCC subtypes reduce survival drastically relative to life expectancy of population-based controls, except for localized rhabdoid and mucinous RCC. Especially, medullary RCC leads to distinct reductions in life expectancy, irrespective of the stage at presentation.