Postoperative complications are associated with poor survival outcome after curative resection for colorectal cancer: A propensity-score analysis

Objective We retrospectively evaluated the impact of postoperative complications on long-term outcomes after curative resection for colorectal cancer (CRC), using propensity-score analysis (PSA). Patients and Methods We reviewed data from 673 consecutive patients with stage I to III CRC, who underwent curative resections between 2005 and 2017. Patients were divided into the complication group (Clavien-Dindo [CD] grade >= 3) and the control group (others). We performed PSA to obtain unbiased estimates of the effects of the oncological background on each outcome. Results We matched for sex, age, American Society of Anesthesiologists grade, location (right colon/left colon/rectum), histology (tub1/tub2/por), pathological tumor depth, and lymph node metastases. Eighty-five patients (12.6%) developed postoperative complications with CD grade >= 3. After PSA, 81 patients were included in each group. The complication group showed significantly worse relapse-free survival (RFS) than the control group (5-year RFS rate: 62% vs 77%; P = .047). In multivariate analysis with inverse probability of treatment weights, the complication group had a higher risk of relapse or death than the control group (hazard ratio: 2.08, 95% confidence interval:1.3-3.3; P = .018). Conclusions Postoperative complications (CD grade >= 3) could cause poor long-term outcomes in patients with stage I to III CRC; their presence requires appropriate adjuvant chemotherapy and follow-up.