Robotic vs Laparoscopic and Open Surgery for Abdominopelvic Cancers

Overview

Robotic surgery has become an increasingly common option for treating cancers in the abdomen and pelvis. However, whether robotic surgery leads to better cancer-related outcomes than laparoscopic (keyhole) surgery or open surgery is still uncertain. Results may differ across cancer types, and factors such as how complex the surgery is and how experienced the surgeon is may also influence the outcome. This retrospective cohort study examined adults who underwent curative-intent surgery for one of seven abdominopelvic cancers (pancreatic, gastric, rectal, cervical, endometrial, kidney, or prostate cancer) at a large tertiary hospital in Seoul, South Korea, between January 2012 and December 2021. Patients were classified into three groups according to the surgical approach they received: open, laparoscopic, or robotic surgery. The main outcome was 1-year disease-free survival, defined as the time from surgery to the first occurrence of cancer recurrence, distant metastasis, or death from any cause. Additional outcomes included 1-year mortality, overall mortality during follow-up, major postoperative complications, acute kidney injury, and length of hospital stay. To reduce differences between groups that might affect the comparison, the study used a statistical method called propensity score overlap weighting. Additional analyses adjusted for surgical complexity, surgeon experience including robotic learning curve, and pathological cancer stage to isolate the effect of the surgical platform itself. The purpose of this study was to evaluate whether the association between surgical approach and early oncologic and perioperative outcomes differed across the seven cancer types, and whether any observed advantage of the robotic platform remained after accounting for these factors.

Study Design This was a single-center, retrospective cohort study conducted at Asan Medical Center, a large tertiary referral center in Seoul, Republic of Korea. The study protocol was approved by the Institutional Review Board of Asan Medical Center (approval number 2026-0316), and the requirement for written informed consent was waived due to the retrospective design. The study is reported in accordance with the Strengthening the Reporting of Cohort, Cross-sectional and Case-control Studies in Surgery (STROCSS) guideline. Study Population Adults aged 18 years or older who underwent curative-intent abdominopelvic surgery for one of seven nonmetastatic malignant solid tumors (pancreatic, gastric, rectal, cervical, endometrial, kidney, or prostate cancer) between January 1, 2012, and December 31, 2021 were considered eligible. Patients were excluded if they had distant metastasis before surgery, presented with recurrent disease from previously treated cancer, or had incomplete key demographic, comorbidity, operative, or outcome data. Exposure Patients were classified into three groups according to the surgical approach: open surgery, laparoscopic surgery, and robotic surgery. Two pairwise cohorts were constructed for comparative effectiveness analyses: (1) open versus robotic surgery for all seven cancer types, and (2) laparoscopic versus robotic surgery for six cancer types (prostate cancer excluded due to absence of laparoscopic prostatectomy at the study institution during the study period). Primary Outcome 1-year disease-free survival (DFS), defined as the interval from surgery to the first occurrence of cancer recurrence, distant metastasis, or death from any cause. The 1-year time horizon was selected because postoperative oncologic surveillance was systematically available during the first postoperative year across the included malignancies. Secondary Outcomes * 1-year all-cause mortality * Overall mortality during the entire follow-up period * Major postoperative complications within 30 days (composite of cardiovascular events, stroke, venous thromboembolism, pneumonia, wound dehiscence, systemic infection, sepsis, acute kidney injury, and urinary tract infection) * Postoperative acute kidney injury (KDIGO criteria) * Hospital length of stay Statistical Analysis Propensity scores were estimated separately for each pairwise comparison within each cancer type using multivariable logistic regression, incorporating demographics, tumor stage, surgical factors, comorbidities, preoperative medications, and laboratory measurements. Overlap weights were applied to emphasize patients with substantial covariate overlap without trimming. Time-to-event outcomes were analyzed using weighted Cox proportional hazards models with robust variance estimation. Pooled estimates across cancer types were obtained from models stratified by cancer type, with heterogeneity assessed by interaction testing. Binary outcomes were analyzed using Firth penalized logistic regression, and length of stay using weighted linear regression after log transformation. E-values were computed to assess sensitivity to unmeasured confounding. Sensitivity Analyses A stepwise doubly robust strategy was applied. Model 1 was the primary overlap-weighted analysis. Model 2 additionally adjusted for surgical complexity (European Society of Cardiology surgical risk category and cancer-specific operation subtypes) and provider-level factors including cumulative robotic experience of the operating surgeon as a proxy for the robotic learning curve. Model 3 further adjusted for pathological severity (advanced T stage, nodal involvement, and FIGO stage where applicable) among patients with available staging.