Background: Minimally invasive surgery (MIS) may improve surgical recovery and reduce time to adjuvant systemic therapy after colon cancer resection. The objective of this study was to determine the effect of MIS on the initiation of adjuvant systemic therapy and survival in patients with stage III colon cancer.
Methods: The 2010-2014 National Cancer Database was queried for patients with resected stage III colon adenocarcinoma, and divided into MIS, which included laparoscopic and robotic approaches, and open surgery. Propensity-score matching was used to balanced open and MIS groups. The main outcome measures were delayed initiation of adjuvant systemic therapy (defined as > 8 weeks after surgery) and 5-year overall survival (OS). Multiple Cox regression was performed to identify independent predictors for 5-year OS, including an interaction between delayed systemic therapy and MIS, and adjusted for clustering at the hospital level.
Results: There were 86,680 patients that were included in this study. Overall, 45% (38,713) underwent MIS colectomy, of which 93% underwent laparoscopic and 7% robotic surgery. After matching, 33,183 open patients were balanced to 33,183 MIS patients. Patient, tumor, and facility characteristics were similar in the matched cohort. More patients in the MIS group received adjuvant therapy within 8 weeks of surgery (49% vs. 42%, p < 0.001), and fewer MIS patients did not receive any systemic therapy (30% vs. 35%, p < 0.001). Delayed initiation of systemic therapy > 8 weeks was associated with worse 5-year OS (HR 1.27, 95%CI 1.19-1.36). MIS was independently associated with improved survival (HR 0.92, 95%CI 0.86-0.97). This relationship remained even if 90-day mortality was excluded.
Conclusions: MIS approaches are associated with less delay to the initiation of adjuvant systemic therapy and improved survival in patients with stage III colon adenocarcinoma. Surgeons should favor MIS approaches for the treatment of stage III colon adenocarcinoma whenever possible.
Keywords: Adjuvant systemic therapy; Colon cancer; Laparoscopy; Minimally invasive surgery; Robotics.