Conditional Relative Survival and Competing Mortality in Surgically Treated Patients with Localized and Regional...

To investigate the 5-year conditional relative survival and competing mortality in surgically treated patients with localized and regional kidney cancer.

Using a nationwide population-based database, the Korea Clinical Data Utilization Network for Research Excellence, conditional relative survival conditioned on 1 to 3 years of survival after diagnosis was measured. These rates were stratified by age, sex, socioeconomic status, comorbidities, and treatment received. Cause of death and estimated cause-specific mortality were also described and considered with competing risks.

This study included a total of 19,749 newly diagnosed patients with kidney cancer who underwent surgical treatment from 2013 to 2019. The baseline conditional relative survival rates for the entire cohort, patients with localized disease, and patients with regional disease were 97.2%, 99.4%, and 82.6%, respectively. After one year, these rates increased to 99.4%, 100.0%, and 95.3%, respectively. Patients who underwent surgery only had the highest baseline conditional relative survival rates (99.3%) compared with those who received surgery with radiotherapy (74.0%), with chemotherapy (38.9%), and with chemotherapy and radiotherapy (16.2%). Specifically, patients who underwent robotic surgery or partial nephrectomy showed higher baseline conditional relative survival rates (>100%) than others. Furthermore, kidney cancer was the leading cause of death (49.6%), followed by other types of cancer and cardiovascular disease. Over time, kidney cancer-specific mortality decreased.

Conditional survival after surgery for localized or regional kidney cancer was high and improved over time. These findings indicate that long-term prognosis varies by stage and patient characteristics and should inform postoperative surveillance.