Lawrence Lee, MD, PhD, Nathalie Wong-Chong, MD, Justin Kelly, MD, George J Nassif, DO, Matthew R Albert, MD, John R Monson, MD. Florida Hospital
Introduction: Minimally invasive surgery(MIS) may improve surgical recovery. In the context of colon cancer, this may lead to fewer delays to adjuvant systemic therapy and improved survival. 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 2004-2014 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. Patients with rectal cancer or those who received preoperative therapy were excluded. 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 86,572 patients that were included in this study. Overall, 45%(38713/86572) underwent MIS colectomy, of which 93% underwent laparoscopic and 7% robotic surgery. The conversion rate was 15%(5448/35857) for laparoscopic and 9%(246/2856) for robotic surgery(p<0.001). In the matched cohort, 33183 open patients were matched to 33183 MIS patients. Patient, tumour, and facility characteristics were similar in the matched cohort. There were fewer delays to systemic therapy in the MIS compared to the open group(31% vs. 35%, p<0.001), and fewer patients that did not receive any systemic therapy(30% vs. 35%, p<0.001). 30- and 90-day mortality was lower in the MIS group(2% vs. 4%, p<0.001; and 4% vs. 7%, p<0.001). After adjusting for possible confounders, a delay to systemic therapy was associated with worse 5-year survival (HR 1.31, 95%CI 1.23-1.39). MIS was independently associated with improved survival(HR 0.82, 95%CI 0.77-0.87), and the interaction between MIS and delayed systemic therapy reported similar survival between non-delayed and delayed systemic therapy amongst the MIS group(HR 1.00, 95%CI 0.90-1.10). This relationship remained even if 90-day mortality was excluded. There was no difference between laparoscopic and robotic approaches.
Conclusions: MIS approaches are associated with less delay to the initiation of adjuvant systemic therapy in patients with stage III colon adenocarcinoma. This may translate into a significant survival benefit for patients treated by laparoscopic or robotic colectomy. Surgeons should favour MIS approaches for the treatment of stage III colon adenocarcinoma whenever possible.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 85088
Program Number: S031
Presentation Session: Colorectal 1 Session
Presentation Type: Podium