Post-operative outcomes in patients with locally advanced colon cancer: a comparison of operative approach.

INTRODUCTION: Surgeons may choose an open approach to locally advanced colon cancer (LACC) because of the elevated conversion rate (minimally invasive to open) in these patients (resulting in part from a judgment of the technical feasibility of a minimally invasive approach). Poorer outcomes have been suggested in those requiring conversion from a minimal access to an open approach; however, the influence of conversion has not been studied in LACC. We sought to compare perioperative outcomes in patients with T4aN2 colon cancer undergoing minimally invasive surgery (MIS), planned open (PO), and converted (CN) procedures to evaluate the influence of conversion in this subgroup. METHODS: A retrospective cohort study was conducted using the NSQIP database. Patients with T4aN2 colon cancer undergoing elective resection were included; rectal/unknown tumor location, and T4b disease were excluded (to ensure homogeneity in surgical management). Patients were divided into cohorts based on approach: PO, MIS, and CN. Summary statistics were compared between groups. Multivariable analysis was conducted for mortality and morbidity outcomes. RESULTS: 1286 cases were included (313 PO, 842 MIS, 131 CN); 10.2% underwent conversion. Those undergoing MIS had a shorter length of stay than those undergoing PO or CN (p < 0.0001). On univariable analysis, CN resulted in increased rates of any complication (p < 0.0001). CN also had a greater rate of anastomotic leak (p = 0.0046) and death (p = 0.05). On multivariable analysis, significant predictors of any complication included age, ASA class, M stage, and approach; however, CN did not increase the risk of complication compared with MIS, whereas PO nearly doubled the risk of complication (OR = 1.98, p = 0.0083). The only significant predictor of mortality on multivariable analysis was age (HR = 1.09, p = 0.0002)-approach was not associated with mortality. CONCLUSION: PO confers the greatest risk of suffering any complication. Surgical approach was not associated with death. Results of our study challenge the notion that conversion is associated with the worst perioperative outcomes and an MIS approach should be considered in patients with LACC.