Risk factors affecting delay of initiating adjuvant chemotherapy for stage III colorectal cancer

Delay in initiating adjuvant chemotherapy (AC) after curative resection of colorectal cancer (CRC) has been reported to lead to poor prognosis, but few studies have looked at associated factors. This study aimed to identify risk factors for delay in initiating AC.

Data from 200 consecutive patients who underwent curative resection and AC for stage III CRC between 2013 and 2018 were retrospectively collected and analyzed.

AC was initiated more than 8 weeks after surgery in 12.5% of patients (the delay group). Compared to those with no delay (the non-delay group), patients in the delay group had significantly higher rates of synchronous double cancers (2.3% vs. 16.0%, p = 0.001), preoperative bowel obstruction (10.3% vs. 32.0%, p = 0.003), laparotomy (56.0% vs. 80.0%, p = 0.02), concomitant resection (2.9% vs. 24.0%, p < 0.001), and postoperative complications (32.0% vs. 56.0%, p = 0.02), and a significantly longer length of hospital stay (median 12 vs. 30 days, p < 0.001). In multivariate analysis, synchronous double cancers (odds ratio 10.2, p = 0.008), preoperative bowel obstruction (odds ratio 4.6, p = 0.01), concomitant resection (odds ratio 5.2, p = 0.03), and postoperative complications of Clavien–Dindo grade ≥ IIIa (odds ratio 4.0, p = 0.03) were identified as independent risk factors for delay in initiating AC.

Careful preoperative treatment planning for CRC patients with synchronous double cancers, preoperative bowel obstruction, and concomitant resection, and management for postoperative complication are necessary to avoid delay in initiating AC.