Factors Affecting Use and Delay (≥8 Weeks) of Adjuvant Chemotherapy after Colorectal Cancer Surgery and the Impact of Chemotherapy-Use and Delay on Oncologic Outcomes

PURPOSE: To evaluate factors affecting the use and delay ≥8 weeks of adjuvant chemotherapy and the impact of chemotherapy use and delay on survival. METHODS: Between 2005 and 2012, consecutive patients with stage II and III colorectal cancer who were treated with major curative resection were enrolled. RESULTS: Among 750 patients with stage II (n = 318) and III (n = 432) disease, 153 (20.4%) did not receive chemotherapy. Among 597 patients with adjuvant chemotherapy, 31 (5.2%) began chemotherapy 8 weeks or more after surgery. Factors associated with not receiving chemotherapy were: age ≥80 years (hazard ratio HR = 5.2), American Society of Anesthesiologists score ≥3 (HR = 1.9), underlying cerebrovascular disease (HR = 1.7), stage II disease (HR = 2.0), presence of postoperative complications (HR = 2.2), or intensive care unit admission (HR = 2.4). Factors associated with chemotherapy delay ≥8 weeks were: male sex (HR = 4.2), rectal primary cancer (HR = 5.4), or presence of postoperative complications (HR = 2.5). Independent prognostic factors for overall survival included TNM III stage (HR = 2.04) and chemotherapy delay ≥8 weeks (HR = 0.39) or <8 weeks (HR = 0.22). Independent prognostic factors for recurrence-free survival were TNM III stage (HR = 2.26) and chemotherapy delay <8 weeks (HR = 0.35). CONCLUSIONS: Postoperative complications were associated with both lack of and delayed chemotherapy. Timely initiation of chemotherapy, defined as <8 weeks, was a favorable prognostic factor for overall and recurrence-free survival. To increase the proportion of patients receiving chemotherapy and timely initiation of chemotherapy, surgical complications should be minimized after curative resection.