The Impact of Chronic Kidney Disease in Patients With Locally Advanced Rectal Cancer Treated With Neoadjuvant Chemoradiation

BACKGROUND: Patients with chronic kidney disease are commonly excluded from clinical trials. The impact of chronic kidney disease on outcomes in patients with locally advanced rectal cancer has not been previously studied. OBJECTIVE: This study aimed to investigate the impact of chronic kidney disease on outcomes in patients with locally advanced rectal cancer. DESIGN: This is a multi-institutional, retrospective cohort study. SETTINGS: This study was conducted at academic and community cancer centers participating in the Canadian Health Outcomes Research Database Consortium Rectal Cancer Database. PATIENTS: Consecutive patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation before curative-intent surgery from 2005 to 2013 were selected. MAIN OUTCOME MEASURES: Disease-free survival, overall survival, pathologic complete response, and neoadjuvant chemotherapy/radiotherapy completion rate were the primary outcomes measured. RESULTS: A total of 1254 patients were included. Median age was 62, and 29%/69% had clinical stage II and III disease. Median estimated creatinine clearance was 93 mL/min, with 11% <60 mL/min (n = 136). There was no significant difference in the completion rate of neoadjuvant chemotherapy (82% vs 85%, p = 0.36) or radiotherapy (93% vs 95%, p = 0.45) between patients with and without chronic kidney disease. Patients with chronic kidney disease were less likely to receive adjuvant chemotherapy (63% vs 77%, p < 0.01). On multivariate analysis, patients with chronic kidney disease had decreased disease-free survival (HR, 1.37; 95% CI, 1.03-1.82; p = 0.03) but not overall survival (HR, 1.23; 95% CI, 0.88-1.75; p = 0.23) or pathologic complete response (OR, 0.83; 95% CI, 0.50-1.39; p = 0.71). LIMITATIONS: This study was limited by its retrospective design and by limited events for overall survival analysis. CONCLUSIONS: In patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation, baseline chronic kidney disease was associated with less use of adjuvant chemotherapy and decreased disease-free survival. Chronic kidney disease was not independently associated with neoadjuvant chemotherapy/radiotherapy completion rate, pathologic complete response, or overall survival. These data suggest that patients with locally advanced rectal cancer with chronic kidney disease may have distinct outcomes and, accordingly, the results of landmark clinical trials may not be generalizable to this population.