RESEARCH ARTICLE 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 delay8 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 chemo-therapy were: age80 years (hazard ratio [HR] = 5.2), American Society of Anesthesiolo-gists score3 (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 delay8 weeks were: male sex (HR = 4.2), rectal primary cancer (HR = 5.4), or presence of postoperative complica-tions (HR = 2.5). Independent prognostic factors for overall survival included TNM III stage (HR = 2.04) and chemotherapy delay8 weeks (HR = 0.39) or <8 weeks (HR = 0.22). Inde-pendent prognostic factors for recurrence-free survival were TNM III stage (HR = 2.26) and chemotherapy delay <8 weeks (HR = 0.35)