LAUSR

Abstract Background Metastatic colorectal cancer (mCRC) occasionally requires surgery because of complications associated with the primary tumor, such as ileus and bleeding. We investigated the effects on chemotherapy (CTx) and the prognosis between primary tumor resection and colostomy without primary tumor resection in mCRC patients (pts), because they are not clear. Methods We reviewed the medical records of the pts with mCRC who underwent surgery with no prior treatment and received CTx after surgery in our hospital between January 2012 and Jun 2018. We evaluated time interval from surgery to CTx and the efficacy of CTx. Results A total of 44 pts with mCRC received CTx following surgery. 34 pts underwent primary tumor resection (resection group) and 10 pts underwent colostomy (colostomy group); the median age was 68.5/72 years, male was 47/60%, performance status of 0 was 85/70% and RAS wild type was 62/50% respectively. The most common reason for surgery was stenosis. Perioperative complications were observed in 3 pts in the resection group. There were no cases that required surgery after introduction of CTx. The median time interval from surgery to CTx was significantly short in colostomy group; 5.43 weeks (w) in the resection group and 3.57 w in the colostomy group (p = 0.01). Approximately 70% of all cases received fluorouracil/oxaliplatin plus bevacizumab as first-line. The median progression-free survival was 11.60 and 10.25 months (m) in the resection group and colostomy group, respectively (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.34-1.97, p = 0.650). The median overall survival was 46.8 m and not reached in the resection group and colostomy group, respectively (HR 0.75, 95% CI 0.21-2.75, p = 0.666). Conclusions In mCRC that required surgery, although there was the advantage of shortened time intervals from surgery to CTx in cases of colostomy, obvious differences in the effects on CTx were not observed between primary tumour resection and colostomy.