On the edge: pathology specimen quality in robotic and laparoscopic proctectomy, a propensity score-matched study

Although robotic surgery has seen increasing adoption over time, its benefits over conventional laparoscopy for rectal cancer resection remain unclear. This study compares composite pathologic specimen quality and overall survival between robotic and laparoscopic proctectomy in a national sample of patients with rectal cancer.

Using the National Cancer Database (2010-2021), we conducted a retrospective cohort study of adults with stage I to III rectal adenocarcinoma who underwent elective laparoscopic or robotic proctectomy. The primary outcome was an optimal composite pathologic specimen, defined as R0 resection margins and the harvest of at least 12 lymph nodes. Propensity score matching balanced baseline covariates, and a Poisson regression model estimated the likelihood of obtaining an optimal specimen. Five-year overall survival was examined using Kaplan-Meier curves.

After propensity score matching, 18,437 patients were included in each cohort. Robotic proctectomy was significantly more likely to yield an optimal composite pathologic specimen (relative risk, 1.04; 95% CI, 1.02-1.05), with lower rates of positive margins (4.5% vs 5.0%; P =.04) and insufficient lymph node yield (19.3% vs 21.9%; P <.001). The 5-year overall survival rate was similar between the groups (82.2% robotic vs 81.9% laparoscopic; P =.54).

Robotic proctectomy was slightly more likely than laparoscopy to yield an optimal composite pathologic specimen, whereas both approaches achieved similar long-term survival. It remains uncertain whether these marginal differences are attributable to technical factors or other influences; future studies should identify which patients derive the greatest benefit from a robotic approach.