Endoscopic resection of T1 colorectal cancer prior to surgery does not affect surgical adverse events and recurrence

Background Although a “no-touch isolation” technique is used in colorectal cancer surgery to reduce the risk of metastatic induction, endoscopic resection (ER) prior to surgery may work against this aim. This study evaluated the effects of initial ER on short- and long-term outcomes in T1 colorectal cancer. Methods This retrospective cohort study enrolled patients with pathological T1 colorectal cancer who underwent colorectal surgical resection at a Japanese tertiary cancer center between 2002 and 2012. A total of 548 eligible patients were divided into two groups: patients initially treated using surgical resection with lymph node dissection (LND) (primary group, n = 304) and patients treated using initial ER and additional surgical resection with LND (secondary group, n = 244). The inverse probability of treatment weighting (IPTW) method based on propensity score was used to compare postoperative complications and long-term recurrence. Results The incidence of postoperative complications with Clavien–Dindo classification grade ≥ II was 10.9% and 7.4% in the primary and secondary groups, respectively ( p = 0.16). Multivariate analysis with a logistic proportional hazard regression model using IPTW revealed no significant differences in postoperative complications between the two groups ( p = 0.79). During a median follow-up after surgery of 61.4 months, recurrence was observed in 3 (1.0%) and 8 (3.3%) patients, respectively ( p = 0.06). Multivariate analysis with a Cox proportional hazard regression model using IPTW revealed no significant differences in recurrence between the two groups ( p = 0.07). Conclusion Our results suggest no significant adverse effects of initial ER prior to surgery on surgical complications and long-term recurrence in T1 colorectal cancer.