Does Delay of Adjuvant Chemotherapy Impact Survival in Patients With Resected Stage II and III Colon Adenocarcinoma?

BACKGROUND: It is unclear whether delays in commencing adjuvant chemotherapy after surgical resection of colon adenocarcinoma adversely impact survival. METHODS: Patients with stage II-III colon adenocarcinoma who received adjuvant chemotherapy at 2 centers were identified through the institutional tumor registry. Time to adjuvant chemotherapy, overall survival (OS), and relapse-free survival (RFS) were calculated from the day of surgery. Patients were dichotomized into early (time to adjuvant chemotherapy <= 60 days) and late treatment (time to adjuvant chemotherapy >60 days) groups. OS and RFS were compared using log-rank test and multivariate analysis by the Cox proportional hazards model. RESULTS: Of 186 patients included in the study, 49 (26%) had received adjuvant chemotherapy >60 days after surgical resection. Thirty percent of the delays were system related (eg, late referrals, insurance authorizations). Time to adjuvant chemotherapy >60 days was associated with significantly worse OS in both univariate analysis and a Cox proportional hazards model (hazard ratio, 2.17; 95% confidence interval, 1.08-4.36). Although difference in RFS between the 2 groups favored time to adjuvant chemotherapy <60, this did not reach statistical significance. CONCLUSIONS: Adjuvant chemotherapy delay >60 days after surgical resection of colon cancer is associated with worse OS. Cancer 2011; 117:2364-70. (C) 2010 American Cancer Society.