We aimed to examine stage-specific oncologic outcomes for young versus conventional-age patients with localized disease in a modern cohort.
Materials and methods:
The Surveillance, Epidemiology and End Results database was queried for patients with T1-T2N0M0 kidney cancer from 1975-2016, including clear cell, papillary, and chromophobe renal cell carcinoma. Patients were stratified into ≤ 40 years-old or > 40 years-old cohorts and underwent definitive treatment via percutaneous ablation, partial nephrectomy, or radical nephrectomy. Primary outcome was cancer-specific survival. Cox regression and Kaplan-Meier analysis were performed.
Results:
A total of 44,673 patients were identified with 41,812 patients in the conventional-age and 2,861 patients in the young cohort with mean ages of 62.1 and 34.7 years old, respectively. The young cohort had a higher proportion of T1a disease compared to the conventional-age cohort (65.2% vs. 58.6%) and a lower proportion of the cT1b (24.4% vs. 29.3%), cT2a (6.8% vs. 8.4%), and cT2b (3.6% vs. 3.7%) disease. Chromophobe histology was more prevalent in the younger population (10.5% vs. 6.6%). Nuclear grade 3 or 4 were more prominent in the conventional-age population (24.8% vs. 19.1%). Cancer-specific death was significantly higher in the conventional-age cohort (2.4% vs. 0.7%). Cox regression analysis demonstrated patients > 40 years old, increasing stage, and higher grade were at independently increased risk of cancer-specific death. Kaplan-Meier analysis showed significantly improved 5-year cancer-specific survival for the young versus conventional-age cohorts when sub-stratified by stage.
Conclusion:
When stratified by stage, young patients with localized kidney cancer experience improved cancer-specific survival.