Surgical resection of T4 colon cancers: an NCDB propensity score-matched analysis of open, laparoscopic, and robotic approaches.

Historically, T4 tumors of the colon have been a contraindication to minimally invasive resection. The purpose of this study was to conduct a National Cancer Database analysis to compare the outcomes after curative treatment for T4 colon cancer between robotic, laparoscopic, and open approaches. The US National Cancer Database was queried for patients with T4 adenocarcinoma of the colon who underwent curative resection. Groups were separated based on approach (open, laparoscopic, robotic). One to one nearest neighbor propensity score matching (PSM) ± 1% caliper was performed across surgical approach cohorts to balance potential confounding covariates. Kaplan-Meier estimation and Cox-proportional hazards regression were used to analyze primary outcome of survival. Secondary outcomes were analyzed by way of logistic regression. Inclusion criteria and PSM identified 876 cases per treatment approach (n = 2628). PSM provided adequate discrimination between treatment cohorts (0.6 < AUC < 0.8) and potential confounding covariates did not significantly differ between cohorts (all respective P > 0.05). Patients who underwent a robotic approach had lower odds of conversion to laparotomy compared to the laparoscopic cohort (P < 0.0001). Laparoscopic and robotic approaches were associated with increased odds of > 12 lymph nodes examined, decreased odds of positive margins, and decreased odds of 30-day readmission, 30-day mortality, and 90-day mortality compared to the open approach. Cox-proportional hazards regression showed that both robotic and laparoscopic approaches were significantly associated with decreased mortality hazards relative to open. Both laparoscopic and robotic-assisted surgeries achieved improved oncologic outcomes and survival compared to open resection of T4 cancers. A robotic-assisted approach was significantly associated with a lower conversion rate compared to the laparoscopic approach. This case-matched study demonstrates safety of using minimally invasive techniques in T4 cancers.
(© 2020. Springer-Verlag London Ltd., part of Springer Nature.)