Stage- and Age-Specific Survival According to Histological Subtype in Renal Cell Carcinoma: A Nationwide Hospital-Based Cancer Registry Analysis in Japan.

OBJECTIVE: To clarify stage- and age-specific overall survival (OS) according to histological subtype among surgically treated patients with RCC in Japan, we analyzed a nationwide hospital-based cancer registry. METHODS: We analyzed data from the Japanese nationwide hospital-based cancer registry and identified patients newly diagnosed with RCC between 2012 and 2014. Eligible patients underwent surgical treatment and had histologically confirmed clear cell, papillary, or chromophobe RCC with pathological stage (pStage) I-IV according to the UICC TNM classification, 7th edition. Patients treated with radiotherapy or local ablative therapies were excluded. OS was estimated using the Kaplan-Meier method and compared using the log-rank test. RESULTS: A total of 17 935 patients met the inclusion criteria, including 15 745 clear cell, 1340 papillary, and 850 chromophobe RCC cases. The 5-year OS rates for clear cell, papillary, and chromophobe RCC were 91.2%, 89.7%, and 93.5% at pStage I, and declined to 37.5%, 21.7%, and 59.3% at pStage IV, respectively. Age-stratified analyses in pStage I disease revealed progressively worse OS with advancing age across all histological subtypes. Among patients aged ≥ 85 years, the 5-year OS rates were 68.2% for clear cell, 50.0% for papillary, and 70.0% for chromophobe RCC. CONCLUSIONS: This nationwide registry-based study provides updated real-world evidence on survival patterns in RCC in Japan. Advanced age was associated with reduced OS even in patients with pStage I disease, highlighting the importance of considering age when interpreting overall survival in surgically treated patients with RCC.