The Distribution of Metastatic Renal Cell Carcinoma by Presenting Tumor Stage in the Modern Era.

Abstract

There is a stage migration for detection of kidney cancer, thus we aim to evaluate the distribution of metastatic renal cell carcinoma by presenting clinical T stage over time. The National Cancer Database was evaluated for patients with metastatic kidney cancer from 2010 to 2016. The primary outcome was the temporal trend of presenting clinical T stage over time. The secondary outcome was overall survival. Kaplan-Meier and Cox regression analyses were performed. The incidence of metastatic kidney cancer has increased, from 3426 new cases in 2010 to 4510 in 2016. While diagnosis of metastasis has increased for all tumor stages over time, there has been a more rapid increase in metastasis of localized renal masses (cT1-T2) as compared to locally advanced disease (cT3-T4). In 2010, 46% of the new metastatic cases diagnosed were cT3-T4, while in 2016 this proportion decreased to 38.2%. Conversely, metastatic cases with cT1-T2 tumors increased from 54% in 2010 to 61.9% in 2016. Cox regression noted an increased risk of death correlating with higher clinical T stage. On Kaplan Meier analysis, the 2-year survival was 29.3%, 30.3%, 28.3%, and 16.0% for cT1, cT2, cT3, and cT4, respectively (logrank P < .001). Metastatic kidney cancer is increasingly diagnosed at a lower presenting cT stage. Survival outcomes worsen with increasing cT stage in the setting of metastasis.