Abstract
Background
Although the safety and effectiveness of robot-assisted surgery for rectal cancer have been demonstrated, its peri-operative safety and long-term survival benefit in patients who have received neoadjuvant chemoradiotherapy (NCRT) remain unclear.
Method
A retrospective cohort of 463 consecutive rectal-cancer patients who underwent either robot-assisted anterior resection or laparoscopic anterior resection after NCRT at Sun Yat-sen University Cancer Center from June 2016 to August 2023 was analyzed. Propensity-score matching (PSM) was applied to balance baseline variables that could affect surgical outcomes and survival. Peri-operative parameters, complication rates, and pathological findings were compared, and 5-year overall survival (OS) and disease-free survival (DFS) were calculated.
Result
A total of 121 patients undergoing robotic-assisted surgery and 342 patients undergoing laparoscopic surgery were included in the study. Operative time was longer in the robot-assisted group both before and after matching. Before matching, the robot-assisted group showed a lower rate of ileostomy (65.3% vs 76.6%, P = 0.021), an advantage that disappeared after PSM (65.3% vs 75.2%, P = 0.063). In the matched cohort, the 5-year DFS was 89.8% for robot-assisted versus 82.3% for laparoscopic (P = 0.130), whereas the 5-year OS was higher in the robot-assisted group than in the laparoscopic group (96.8% vs 86.8%; P = 0.019). In the primary preoperative covariate-adjusted Cox model after PSM, the association between robot-assisted surgery and OS was attenuated and did not reach conventional statistical significance (HR = 0.231, 95% CI 0.052–1.015; P = 0.052).
Conclusions
Robot-assisted and laparoscopic surgery showed comparable perioperative outcomes and DFS after NCRT for rectal cancer. Although an apparent OS difference was observed in the matched cohort, this finding was attenuated in the primary preoperative covariate-adjusted Cox model and should be interpreted cautiously given the potential for residual confounding.
Supplementary Information
The online version contains supplementary material available at https://doi.org/10.1186/s12893-026-03956-3.
Keywords: Rectal cancer, Robot-assisted surgery, Neoadjuvant chemoradiotherapy
Introduction
In recent years, neoadjuvant chemoradiotherapy (NCRT) has become the standard treatment for patients with locally advanced rectal cancer [1, 2]. Previous studies have demonstrated that NCRT increases the 5-year disease-free survival (DFS) rate to 73% and the overall survival (OS) rate to 80% [3–5]. Furthermore, NCRT significantly enhances tumor regression, increases rates of complete tumor excision with clear margins, and improves sphincter preservation; in some patients, it even achieves a clinical complete response (CR), thus exempting them from radical surgery [6, 7]. However, despite substantial oncologic benefit, 70 ~ 80% of patients still require surgical intervention after chemoradiotherapy [8, 9], which is complicated by treatment-induced tissue edema, increased serous effusion, and intestinal fibrosis, all of which contribute to greater operative difficulty and higher risk of complications [10–13].
Moreover, long-term oncologic outcomes following laparoscopic versus open surgery have been shown to be comparable. The introduction of a laparoscopic camera has enabled more precise dissection of pelvic structures; the study by Jiang W et al. reported that laparoscopic surgery increased sphincter preservation rates by 6% compared with open surgery [14–16]. Nonetheless, the unique challenges posed by low rectal tumors—such as osseous barriers and a confined surgical field—place considerable demands on both the surgeon and the assistant. The advent of robot-assisted surgical systems has partially overcome these obstacles. Prior research has confirmed that robotic platforms provide enhanced anatomical precision and a three-dimensional view of the pelvis [17]. Furthermore, the articulating robotic instruments offer significant advantages for reinforcing anastomoses and operating within narrow spaces, which is critical for securing the fragile anastomosis in edematous bowel walls after NCRT. In terms of surgical quality, robot-assisted surgery has been shown to improve circumferential resection margin (CRM) status, reduce conversion rates to open surgery, decrease postoperative complications, shorten recovery times, and optimize urinary and sexual function [18–20].
However, prior studies of robot-assisted rectal cancer surgery have rarely specifically addressed operative safety in patients following NCRT, nor have they focused on long-term oncologic outcomes [21].Therefore, this single-center clinical study from China aims to compare the safety and oncologic efficacy of robot-assisted versus laparoscopic surgery in rectal cancer patients treated with NCRT, and to evaluate their long-term survival results.
Method
Normal information
Consecutive retrospective data were collected for patients who, from June 2016 to August 2023 at the Sun Yat-sen University Cancer Center, received NCRT followed by curative robot-assisted or laparoscopic surgery for rectal cancer. Inclusion criteria were: (1) rectal adenocarcinoma with proficient mismatch-repair/microsatellite-stable (pMMR/MSS) status confirmed by preoperative biopsy; (2) completion of NCRT—either total neoadjuvant therapy (TNT) or conventional concurrent chemoradiotherapy (CRT)—followed by curative resection; (3) surgery initiated with the da Vinci Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA) or conventional laparoscopy, with complete diagnostic and therapeutic records available [22]; (4) preoperative American Society of Anesthesiologists (ASA) physical-status classification I–II. Exclusion criteria were: (1) absence of laparoscopic or robot-assisted surgery; (2) contraindications to robot-assisted surgery defined in the 2015 Expert Consensus on Robotic Colorectal Surgery or other contraindications to laparoscopy; (3) severe comorbidities such as significant hepatic or renal dysfunction or leukopenia that rendered the patient unfit for surgery; (4) emergency surgery necessitated by tumor obstruction, bleeding, or related acute events.
This study comprehensively evaluated demographic characteristics, tumor features, perioperative outcomes, postoperative complications, and oncologic results. The primary endpoint of this study was perioperative safety and short-term surgical outcomes after NCRT, including operative parameters, postoperative complications, and pathological resection quality. Secondary endpoints included long-term oncologic outcomes, including DFS and OS. The protocol was approved by the Ethics Committee of Sun Yat-sen University Cancer Center (Approval No. B2024-331), and all data have been deposited in the Research Data Deposit platform (RDD No. RDDA2024411157). The retrospective study was reported in accordance with the STROBE guidelines [23].
Preoperative preparation and surgical techniques
Six to eight weeks after completion of the last radiotherapy fraction, the attending surgeon assessed each patient for tumor resectability and operative fitness. Preoperative anemia was defined as hemoglobin levels < 130 g/L in males and < 120 g/L in females. Preoperative hypoalbuminemia was defined as a serum albumin level < 40 g/L, and leukopenia was defined as a preoperative white blood cell count < 3.5 × 109/L. All blood samples were collected within seven days prior to surgery. Tumor location was determined preoperatively by colonoscopy. All patients underwent mechanical bowel preparation with polyethylene glycol (PEG) without oral antibiotics. Cefamandole nafate was administered intravenously during the operation and for 24 h post-operatively for infection prophylaxis. For tumors whose upper margin was 10–12 cm from the anal verge, a partial mesorectal excision (PME) was performed; lesions located 5–6 cm from the anal verge underwent total mesorectal excision (TME).
Five surgeons—each with ≥ 5 years of experience in both laparoscopic and robot-assisted colorectal surgery—carried out all procedures, employing standard techniques for anterior resection (AR). Splenic‐flexure mobilization was undertaken whenever inadequate colonic or mesenteric length threatened a tension-free anastomosis. Anastomotic integrity was confirmed by an intraoperative air-leak test. Based on intraoperative findings, the lead surgeon decided whether to fashion a prophylactic loop ileostomy to reduce the risk of anastomotic leakage and re-operation. All resected specimens were submitted for pathological examination, and postoperative complications were recorded and evaluated within 30 days after surgery. The grading of complications was performed according to the Clavien-Dindo classification [24]. Anastomotic leakage grading was based on the recommendations of the International Study Group of Rectal Cancer (ISREC) [25].
Follow-up
According to NCCN guidelines, patients were followed every three months for the first two postoperative years and every six months during the third year. Each visit comprised a physical examination, measurement of serum tumor markers (carcinoembryonic antigen [CEA] and carbohydrate antigen 19–9 [CA19-9]), abdominal ultrasonography, and chest radiography; chest, abdominal, and pelvic computed tomography and colonoscopy were performed annually. DFS was defined as the interval from the date of surgery to tumor recurrence, death, or last follow-up, whereas OS was defined as the interval from surgery to death from any cause or last follow-up. Patients without any event (recurrence or death) at the date of last follow-up were regarded as censored observations. The cutoff date for follow-up was April 2025.
Statistical analysis
Statistical analyses and graphing were performed with Python 3.11.1 and GraphPad Prism. Quantitative variables are presented as medians (M) with interquartile ranges (IQR), and categorical variables as counts (n) with percentages (%). Between-group comparisons were conducted using Fisher’s exact test or Pearson’s χ2 test. Propensity scores were estimated using a logistic regression model26 and 1:2 nearest-neighbor matching was then performed to balance relevant preoperative covariates. DAV was dichotomized at 10 cm as a pragmatic and clinically meaningful cutoff reflecting tumor location and potential differences in operative characteristics, rather than being derived from the empirical distribution of the present cohort. Matching was performed without replacement and without a caliper. Patients with missing values in any of the variables included in the propensity model were excluded from propensity score estimation and subsequent matching. The c-statistic of the propensity score model was 0.682. Survival curves were compared with the log-rank test. For conventional prognostic-factor analyses, variables significant in univariate analysis were entered into multivariable Cox regression. Additional sensitivity Cox models were constructed using prespecified covariates, including a model restricted to preoperative baseline variables and a model incorporating TRG. The Cox model restricted to preoperative baseline covariates after PSM was used for the primary adjusted interpretation of OS. Cox models including postoperative pathological variables, such as pT stage, pN stage, tumor diameter, TRG, and postoperative complications, were considered exploratory prognostic analyses rather than primary causal adjustment models. All tests were two-sided, and P < 0.05 was considered statistically significant.
Result
Patient characteristics
Among the 463 rectal cancer patients who received NCRT and were enrolled in this study, the median age was 58 years (IQR: 50.00–64.00), including 121 patients who underwent robotic-assisted surgery and 342 who underwent laparoscopic surgery. Of these patients, 121 (26.1%) underwent robot-assisted surgery and 342 (73.9%) underwent laparoscopic resection. The median DAV was 7.00 cm (IQR: 5.00–10.00), and the median body mass index (BMI) was 22.89 kg/m2 (IQR: 21.11–24.80). Regarding clinical staging, 46 patients (9.9%) were classified as cT2, 286 (61.8%) as cT3, and 131 (28.3%) as cT4. Nodal status distribution was 217 (46.9%) cN1 and 84 (18.1%) cN2. Tumor-marker assays revealed that 61 patients (13.2%) had a CEA level > 5 ng/mL and 30 (6.5%) had a CA19-9 level > 35 U/mL. For comorbidities, hypertension was present in 94 patients (20.3%) and diabetes mellitus in 59 (12.7%). Preoperative laboratory evaluations identified anemia in 116 patients (25.1%), leukopenia in 175 (37.8%), and hypoalbuminemia in 139 (30.0%). The median interval between completion of radiotherapy and surgery was 70 days (IQR: 60.00–87.50 days). Detailed baseline characteristics are summarized in Table 1.
Table 1.
Patient characteristics
| Characteristics | Number of patients (%) | |
|---|---|---|
| Age(years) | ||
| Median(IQR) | 58 (50–64) | |
| ≤60 | 354 (76.5%) | |
| >60 | 109 (23.5%) | |
| Gender | ||
| Female | 167 (36.1%) | |
| Male | 296 (63.9%) | |
| Hypertension | ||
| Absent | 369 (79.7%) | |
| Present | 94 (20.3%) | |
| Diabetes | ||
| Absent | 404 (87.3%) | |
| Present | 59 (12.7%) | |
| BMI | ||
| Median(IQR) | 22.89 (21.11–24.80) | |
| cT stage | ||
| 2 | 46 (9.9%) | |
| 3 | 286 (61.8%) | |
| 4 | 131 (28.3%) | |
| cN stage | ||
| 0 | 162 (35.0%) | |
| 1 | 217 (46.9%) | |
| 2 | 84 (18.1%) | |
| Preoperative hemoglobin (g/dL) | ||
| Median(IQR) | 126.0 (115.0–136.0) | |
| Preoperative WBC (× 10⁹/L) | ||
| Median(IQR) | 4.36 (3.62–5.29) | |
| Preoperative serum albumin (g/L) | ||
| Median(IQR) | 41.70 (39.35–43.95) | |
| Preoperative CEA level (ng/mL) | ||
| Median(IQR) | 2.47 (1.55–3.74) | |
| Preoperative CA19-9 level (U/mL) | ||
| Median(IQR) | 12.78 (7.60–20.12) | |
| Anemia | ||
| Absent | 347 (74.9%) | |
| Present | 116 (25.1%) | |
| Leukopenia | ||
| Absent | 288 (62.2%) | |
| Present | 175 (37.8%) | |
| Hypoalbuminemia | ||
| Absent | 324 (70.0%) | |
| Present | 139 (30.0%) | |
| CEA(ng/ml) | ||
| ≤5 | 402 (86.8%) | |
| >5 | 61 (13.2%) | |
| CA19-9(U/ml) | ||
| ≤35 | 433 (93.5%) | |
| >35 | 30 (6.5%) | |
| DAV(cm) | ||
| Median(IQR) | 7.00 (5.00–10.00) | |
| Radiotherapy-to-surgery interval(days) | ||
| Median(IQR) | 70.00 (60.00–87.50) | |
IQR interquartile range, WBC white blood cell count, CEA carcinoembryonic Antigen, CA19-9 carbohydrate antigen 19–9, DAV distance from the anal vergel, BMI body mass index
After patients were stratified into the robot-assisted and laparoscopic cohorts, factors potentially affecting operative complexity, perioperative complications, and survival outcomes were compared. χ2 testing demonstrated significantly different proportions of hypoalbuminemia (41.3% vs 26.0%, P = 0.0024), elevated CA19-9 (11.6% vs 4.7%, P = 0.015), and DAV < 10 cm (30.6% vs 16.7%, P = 0.0017) between the two groups (Table 2). Following 1:2 PSM, the distributions of hypoalbuminemia (41.3% vs 36.8%, P = 0.468), elevated CA19-9 (11.6% vs 6.6%, P = 0.157), DAV < 10 cm (30.6% vs 23.6%, P = 0.189), and all other covariates became comparable (Table 2). Standardized mean differences (SMDs) further confirmed covariate balance, with all post-matching SMD absolute values below 0.1, indicating satisfactory equivalence between the robot-assisted and laparoscopic cohorts (Fig. 1). The detailed distributions of the covariates in the robotic and laparoscopic groups before and after matching are shown in Table 2.
Table 2.
Baseline data of the patients in the two groups
| Before PSM | After PSM | |||||||
|---|---|---|---|---|---|---|---|---|
| Robotic group (n = 121. %) |
Laparoscopic group (n = 342, %) |
χ2 | P value | Robotic group (n = 121, %) |
Laparoscopic group (n = 242, %) |
χ2 | P value | |
| Age(years) | ||||||||
| < 65 | 90 (74.4%) | 264 (77.2%) | 0.25 | 0.616 | 90 (74.4%) | 178 (73.6%) | 0.00 | 0.967 |
| ≥ 65 | 31 (25.6%) | 78 (22.8%) | 31 (25.6%) | 64 (26.4%) | ||||
| Gender | ||||||||
| Female | 46 (38.0%) | 121 (35.4%) | 0.17 | 0.683 | 46 (38.0%) | 89 (36.8%) | 0.01 | 0.908 |
| Male | 75 (62.0%) | 221 (64.6%) | 75 (62.0%) | 153 (63.2%) | ||||
| Hypertension | ||||||||
| No | 100 (82.6%) | 269 (78.7%) | 0.65 | 0.420 | 100 (82.6%) | 189 (78.1%) | 0.77 | 0.382 |
| Yes | 21 (17.4%) | 73 (21.3%) | 21 (17.4%) | 53 (21.9%) | ||||
| Diabetes | ||||||||
| No | 111 (91.7%) | 293 (85.7%) | 2.43 | 0.119 | 111 (91.7%) | 206 (85.1%) | 2.62 | 0.106 |
| Yes | 10 (8.3%) | 49 (14.3%) | 10 (8.3%) | 36 (14.9%) | ||||
| BMI(kg/m2) | ||||||||
| >24 | 79 (65.3%) | 223 (65.2%) | 0.00 | 1.000 | 79 (65.3%) | 167 (69.0%) | 0.35 | 0.552 |
| ≤24 | 42 (34.7%) | 119 (34.8%) | 42 (34.7%) | 75 (31.0%) | ||||
| cT stage | ||||||||
| 0–3 | 90 (74.4%) | 242 (70.8%) | 1.41 | 0.493 | 90 (74.4%) | 167 (69.0%) | 2.25 | 0.325 |
| 4 | 31 (25.6%) | 100 (29.2%) | 31 (25.6%) | 75 (31.0%) | ||||
| cN stage | ||||||||
| 0 | 48 (39.7%) | 114 (33.3%) | 5.20 | 0.158 | 48 (39.7%) | 76 (31.4%) | 6.88 | 0.076 |
| 1–2 | 73 (60.3%) | 228 (66.7%) | 73 (60.3%) | 166 (68.6%) | ||||
| Anemia | ||||||||
| No | 93 (76.9%) | 254 (74.3%) | 0.20 | 0.658 | 93 (76.9%) | 168 (69.4%) | 1.86 | 0.173 |
| Yes | 28 (23.1%) | 88 (25.7%) | 28 (23.1%) | 74 (30.6%) | ||||
| Leukopenia | ||||||||
| No | 74 (61.2%) | 214 (62.6%) | 0.03 | 0.867 | 74 (61.2%) | 144 (59.5%) | 0.04 | 0.850 |
| Yes | 47 (38.8%) | 128 (37.4%) | 47 (38.8%) | 98 (40.5%) | ||||
| Hypoalbuminemia | ||||||||
| No | 71 (58.7%) | 253 (74.0%) | 9.24 | 0.002 | 71 (58.7%) | 153 (63.2%) | 0.53 | 0.468 |
| Yes | 50 (41.3%) | 89 (26.0%) | 50 (41.3%) | 89 (36.8%) | ||||
| CEA(ng/ml) | ||||||||
| ≤5 | 103 (85.1%) | 299 (87.4%) | 0.24 | 0.626 | 103 (85.1%) | 207 (85.5%) | 0.00 | 1.000 |
| >5 | 18 (14.9%) | 43 (12.6%) | 18 (14.9%) | 35 (14.5%) | ||||
| CA19-9(U/ml) | ||||||||
| ≤35 | 107 (88.4%) | 326 (95.3%) | 5.91 | 0.015 | 107 (88.4%) | 226 (93.4%) | 2.00 | 0.157 |
| >35 | 14 (11.6%) | 16 (4.7%) | 14 (11.6%) | 16 (6.6%) | ||||
| DAV(cm) | ||||||||
| ≤10 | 84 (69.4%) | 285 (83.3%) | 9.85 | 0.002 | 84 (69.4%) | 185 (76.4%) | 1.72 | 0.189 |
| >10 | 37 (30.6%) | 57 (16.7%) | 37 (30.6%) | 57 (23.6%) | ||||
| Radiotherapy-to-surgery interval(weeks) | ||||||||
| ≤8 | 32 (26.4%) | 58 (17.0%) | 4.55 | 0.033 | 32 (26.4%) | 58 (24.0%) | 0.15 | 0.698 |
| >8 | 89 (73.6%) | 284 (83.0%) | 89 (73.6%) | 184 (76.0%) | ||||
BMI body mass index, CEA carcinoembryonic antigen, CA19-9 carbohydrate antigen 19–9, DAV distance from the anal verge
Fig. 1.
Standardized mean differences (SMDs) of baseline covariates between the robot-assisted and laparoscopic groups before and after propensity score matching
Postoperative outcomes and pathological outcomes
Intra-operative outcomes, postoperative complications, and pathological findings are summarized in Table 3. To improve interpretability, operative time and postoperative hospital stay were additionally summarized as median (IQR) values before matching. Operative time was 262 (230–310) min in the robot-assisted group versus 236 (185.8–299.0) min in the laparoscopic group, and postoperative hospital stay was 6 (5–6) versus 5 (4–6) days. Before matching, the robot-assisted cohort showed a significantly higher proportion of procedures lasting > 180 min (95.0% vs 77.8%, P < 0.0001) and a significantly lower rate of prophylactic ileostomy (65.3% vs 76.6%, P = 0.021) than the laparoscopic cohort. After PSM, the difference in operative time > 180 min persisted (95.0% vs 78.5%, P = 0.0001), whereas intra-operative fluid administration, urine output, blood loss, transfusion rate, conversion to laparotomy, and the proportion of hospital stays > 7 days showed no significant differences either before or after matching.
Table 3.
Perioperative outcomes of the patients in the two groups
| Before PSM | After PSM | |||||||
|---|---|---|---|---|---|---|---|---|
| Outcome | Robotic group (n = 121, %) |
Laparoscopic group (n = 342, %) |
χ2 | P value | Robotic group (n = 121, %) |
Laparoscopic group (n = 242, %) |
χ2 | P value |
| Operation time(min) | ||||||||
| ≤ 180 | 6 (5.0%) | 76 (22.2%) | 17.11 | < 0.001 | 6 (5.0%) | 52 (21.5%) | 15.21 | < 0.001 |
| > 180 | 115 (95.0%) | 266 (77.8%) | 115 (95.0%) | 190 (78.5%) | ||||
| Postoperative hospital stay(days) | ||||||||
| ≤ 7 | 105 (86.8%) | 294 (86.0%) | 0.00 | 0.945 | 105 (86.8%) | 200 (82.6%) | 0.74 | 0.389 |
| > 7 | 16 (13.2%) | 48 (14.0%) | 16 (13.2%) | 42 (17.4%) | ||||
| Fluid replacement(ml) | ||||||||
| ≤ 2500 | 111 (91.7%) | 321 (93.9%) | 0.35 | 0.554 | 111 (91.7%) | 225 (93.0%) | 0.05 | 0.832 |
| > 2500 | 10 (8.3%) | 21 (6.1%) | 10 (8.3%) | 17 (7.0%) | ||||
| Urine output(ml) | ||||||||
| ≤ 500 | 84 (69.4%) | 226 (66.1%) | 0.31 | 0.576 | 84 (69.4%) | 159 (65.7%) | 0.35 | 0.554 |
| > 500 | 37 (30.6%) | 116 (33.9%) | 37 (30.6%) | 83 (34.3%) | ||||
| Intraoperative blood loss(ml) | ||||||||
| ≤ 100 | 113 (93.4%) | 321 (93.9%) | 0.00 | 1.000 | 113 (93.4%) | 227 (93.8%) | 0.00 | 1.000 |
| > 100 | 8 (6.6%) | 21 (6.1%) | 8 (6.6%) | 15 (6.2%) | ||||
| Blood transfusion | ||||||||
| No | 119 (98.3%) | 330 (96.5%) | 0.51 | 0.474 | 119 (98.3%) | 232 (95.9%) | 0.87 | 0.350 |
| Yes | 2 (1.7%) | 12 (3.5%) | 2 (1.7%) | 10 (4.1%) | ||||
| Open surgery | ||||||||
| No | 120 (99.2%) | 330 (96.5%) | 1.48 | 0.224 | 120 (99.2%) | 232 (95.9%) | 1.98 | 0.159 |
| Yes | 1 (0.8%) | 12 (3.5%) | 1 (0.8%) | 10 (4.1%) | ||||
| Ileostomy | ||||||||
| No | 42 (34.7%) | 80 (23.4%) | 5.33 | 0.021 | 42 (34.7%) | 60 (24.8%) | 3.45 | 0.063 |
| Yes | 79 (65.3%) | 262 (76.6%) | 79 (65.3%) | 182 (75.2%) | ||||
| Postoperative complications | ||||||||
| Absent | 109 (90.1%) | 317 (92.7%) | 0.51 | 0.475 | 110 (90.9%) | 222 (91.7%) | 0.00 | 0.947 |
| Present | 12 (9.9%) | 25 (7.3%) | 11 (9.1%) | 20 (8.3%) | ||||
| Leakage | ||||||||
| Absent | 114 (94.2%) | 320 (93.6%) | 0.00 | 0.973 | 114 (94.2%) | 224 (92.6%) | 0.13 | 0.714 |
| Present | 7 (5.8%) | 22 (6.4%) | 7 (5.8%) | 18 (7.4%) | ||||
| Anastomotic bleeding | ||||||||
| Absent | 120 (99.2%) | 327 (95.6%) | 2.41 | 0.121 | 120 (99.2%) | 229 (94.6%) | 3.35 | 0.067 |
| Present | 1 (0.8%) | 15 (4.4%) | 1 (0.8%) | 13 (5.4%) | ||||
| Pelvic bleeding | ||||||||
| Absent | 121 (100.0%) | 342 (100.0%) | 0.00 | 1.000 | 121 (100.0%) | 242 (100.0%) | 0.00 | 1.000 |
| Chylous leakage | ||||||||
| Absent | 120 (99.2%) | 342 (100.0%) | 0.30 | 0.587 | 120 (99.2%) | 242 (100.0%) | 0.13 | 0.723 |
| Present | 1 (0.8%) | 0 (0.0%) | 1 (0.8%) | 0 (0.0%) | ||||
| Small intestinal obstruction | ||||||||
| Absent | 118 (97.5%) | 339 (99.1%) | 0.76 | 0.383 | 118 (97.5%) | 240 (99.2%) | 0.63 | 0.426 |
| Present | 3 (2.5%) | 3 (0.9%) | 3 (2.5%) | 2 (0.8%) | ||||
| Delayed wound healing | ||||||||
| Absent | 120 (99.2%) | 338 (98.8%) | 0.00 | 1.000 | 120 (99.2%) | 240 (99.2%) | 0.00 | 1.000 |
| Present | 1 (0.8%) | 4 (1.2%) | 1 (0.8%) | 2 (0.8%) | ||||
| Reoperation | ||||||||
| Absent | 114 (94.2%) | 335 (98.0%) | 3.08 | 0.079 | 114 (94.2%) | 235 (97.1%) | 1.12 | 0.289 |
| Present | 7 (5.8%) | 7 (2.0%) | 7 (5.8%) | 7 (2.9%) | ||||
| pT stage | ||||||||
| 1–3 | 118 (97.5%) | 316 (92.4%) | 3.17 | 0.075 | 118 (97.5%) | 226 (93.4%) | 2.01 | 0.157 |
| 4 | 3 (2.5%) | 26 (7.6%) | 3 (2.5%) | 16 (6.6%) | ||||
| pN stage | ||||||||
| 0 | 105 (86.8%) | 274 (80.1%) | 2.24 | 0.135 | 105 (86.8%) | 198 (81.8%) | 1.10 | 0.294 |
| 1–2 | 16 (13.2%) | 68 (19.9%) | 16 (13.2%) | 44 (18.2%) | ||||
| Total lymph nodes yield(n) | ||||||||
| ≤ 12 | 96 (79.3%) | 271 (79.2%) | 0.00 | 1.000 | 96 (79.3%) | 189 (78.1%) | 0.02 | 0.892 |
| > 12 | 25 (20.7%) | 71(20.8%) | 25 (20.7%) | 53 (21.9%) | ||||
| TRG | ||||||||
| 0–2 | 102 (84.3%) | 315 (92.1%) | 5.25 | 0.022 | 102 (84.3%) | 227 (93.8%) | 7.50 | 0.006 |
| 3–4 | 19 (15.7%) | 27 (7.9%) | 19 (15.7%) | 15 (6.2%) | ||||
| Maximum tumor diameter(cm) | ||||||||
| ≤ 5 | 117 (96.7%) | 336 (98.2%) | 0.42 | 0.519 | 117 (96.7%) | 237 (97.9%) | 0.13 | 0.720 |
| > 5 | 4 (3.3%) | 6 (1.8%) | 4 (3.3%) | 5 (2.1%) | ||||
PSM propensity score matching
A total of 37 patients (8.0%) experienced postoperative complications: 16 (3.5%) anastomotic hemorrhage, 29 (6.3%) anastomotic leakage, 1 (0.2%) chylous fistula, no pelvic hemorrhage, 6 (1.3%) small-bowel obstruction, and 5 (1.1%) delayed wound healing; no anastomotic stricture was observed. Among the 29 anastomotic leaks, 21 (72.4%) were grade B and 8 (27.6%) grade C; 6 grade B and 1 grade C leaks occurred in the robot-assisted cohort, whereas 15 grade B and 7 grade C leaks occurred in the laparoscopic cohort. Endoscopic hemostasis-controlled bleeding in eight patients the same day, and eight others achieved hemostasis surgically. Grade B leaks resolved with peritoneal lavage, whereas grade C leaks required surgery after lavage and intravenous antibiotics failed to alleviate systemic infection; during laparotomy, contamination was cleared and the anastomosis repaired or reconstructed, with symptom relief in all cases within six days and no recurrence. Wound-healing disorders resolved with appropriate treatment. Of all complications, 23 were grade II and 14 grade III, and 14 patients (3.0%) underwent reoperation; no in-hospital deaths occurred.
Regarding pathological outcomes, all patients achieved R0 resection of the primary lesion. Before PSM, no significant differences were noted in pT4 (7.6% vs 2.5%, P = 0.075), pN1–2 (19.9% vs 13.2%, P = 0.135), tumor diameter > 5 cm (1.8% vs 3.3%, P = 0.519), or lymph-node yield > 12 (20.8% vs 20.7%, P = 1.000) between cohorts; the same held true after PSM for pT4 (6.6% vs 2.5%, P = 0.157), pN1–2 (18.2% vs 13.2%, P = 0.294), lymph-node yield > 12 (21.9% vs 20.7%, P = 0.892), and tumor diameter > 5 cm (2.1% vs 3.3%, P = 0.720). Notably, both before and after matching, the proportion of TRG 3–4 was lower in the laparoscopic cohort than in the robot-assisted cohort (pre-matching 7.9% vs 15.7%, P = 0.022; post-matching 6.2% vs 15.7%, P = 0.0062).
Survival analysis
The median follow-up for the entire cohort was 35 months (IQR, 21.47–56.30). Therefore, the reported 5-year OS and DFS values should be interpreted as actuarial estimates derived from Kaplan–Meier analysis, and caution is warranted given the relatively limited maturity of the survival data. Overall, 438 patients (94.6%) were alive, and 59 (12.7%) experienced locoregional recurrence or distant metastasis, including 5 patients with locoregional recurrence only, 52 with distant metastasis only, and 2 with both locoregional and distant recurrence. Fifteen patients (3.24%) died of disease progression and 10 died of non-cancer-related causes. In the robot-assisted cohort, 119 patients (98.4%) were alive, 11 (9.09%) developed recurrence or metastasis, including 1 patient with locoregional recurrence only and 10 with distant metastasis only, and 2 (1.65%) died. In the laparoscopic cohort, 319 patients (93.4%) were alive, 48 (14.0%) experienced recurrence or metastasis, including 4 patients with locoregional recurrence only, 42 with distant metastasis only, and 2 with both locoregional and distant recurrence, and 23 (6.73%) died.
Survival curves are presented in Fig. 2. No significant difference in DFS was observed between cohorts either before PSM (5-year DFS, 89.8% vs 81.7%, P = 0.088) or after PSM (89.8% vs 82.3%, P = 0.130) (Fig. 2a, b). In contrast, the robot-assisted cohort exhibited a significantly higher 5-year OS both before PSM (96.8% vs 88.6%, P = 0.030) and after PSM (96.8% vs 86.8%, P = 0.019) (Fig. 2c, d).
Fig. 2.
Kaplan–Meier curves of patients who underwent robot-assisted surgery and laparoscopic surgery before and after matching. A DFS for patients who underwent robot-assisted and laparoscopic surgery before matching; B DFS for patients who underwent robot-assisted and laparoscopic surgery after matching; C OS for patients who underwent robot-assisted and laparoscopic surgery before matching; D OS for patients who underwent robot-assisted and laparoscopic surgery after matching
For the primary adjusted interpretation of OS, we used the Cox model restricted to preoperative baseline covariates after PSM. In this model, the association between robot-assisted surgery and OS was attenuated and did not reach conventional statistical significance (HR = 0.231, 95% CI 0.052–1.015; P = 0.052; Table S3). Conventional prognostic-factor Cox analyses, including models that incorporated postoperative pathological variables, are presented as exploratory supplementary analyses (Tables S1 and S2).
Figure 3 shows an exploratory subgroup analysis of 5-year DFS after PSM across 10 clinicopathological variables. In female patients, laparoscopic surgery was associated with a higher risk of recurrence or death than robotic surgery (HR = 4.454, 95% CI 1.018–19.49; P = 0.047). Given that this sex-specific analysis was not pre-specified and no formal adjustment for multiple comparisons was performed, this finding should be interpreted as exploratory. A formal interaction test between surgical approach and sex did not reach statistical significance (P for interaction = 0.089), further supporting that this subgroup finding should not be interpreted as confirmatory evidence of a true sex-specific treatment effect.
Fig. 3.
Exploratory subgroup analysis of disease-free survival comparing robot-assisted and laparoscopic surgery across 10 clinicopathological variables after propensity score matching. The P value for interaction between surgical approach and sex was 0.089
To further evaluate the potential influence of residual TRG imbalance, exploratory Kaplan–Meier analyses stratified by TRG were performed in the matched cohort. No significant differences were observed between the TRG 0–2 and TRG 3–4 groups in either DFS (log-rank P = 0.201) or OS (log-rank P = 0.825) (Figure S1). In addition, an exploratory sensitivity Cox analysis incorporating TRG showed that TRG was not significantly associated with either OS or DFS in the matched cohort (Table S4). Because TRG is a postoperative pathological variable, this analysis was considered exploratory and was not used as the primary causal interpretation of the surgical approach effect.
Discussion
This single-centre retrospective study compared robot-assisted and conventional laparoscopic resection in patients with rectal cancer who had received NCRT. Overall, the two minimally invasive approaches showed broadly similar perioperative outcomes in this cohort. Intraoperative parameters and postoperative recovery were largely equivalent between the two groups; no significant differences were observed in intraoperative blood loss or length of hospital stay, suggesting that the robot-assisted approach was not associated with increased perioperative risk. However, a higher proportion of procedures in the robot-assisted group exceeded 180 min in duration, both before and after propensity matching. The incidence of Clavien–Dindo grade II or higher complications within 30 days postoperatively was comparable between groups, consistent with the findings of the ROLARR trial 19. Regarding pathological resection quality, both cohorts achieved R0 margins, and the number of harvested lymph nodes was comparable. Over the median follow-up, 5-year DFS rates were essentially equivalent between robot-assisted and laparoscopic surgery, whereas an apparent difference in 5-year OS was observed in Kaplan–Meier analysis. These findings suggest that robot-assisted surgery provides perioperative safety and DFS comparable to those of conventional laparoscopy in rectal cancer patients treated with NCRT. For the adjusted survival interpretation, the preoperative covariate-adjusted Cox model after PSM was regarded as the primary model; in this model, the association between robot-assisted surgery and OS was attenuated and did not reach conventional statistical significance. Cox models incorporating postoperative pathological variables were interpreted only as exploratory prognostic analyses. Therefore, the apparent OS difference should be interpreted cautiously and should not be considered definitive evidence of a causal survival advantage of robot-assisted surgery.
Our institutional data affirm the reliability and safety of robot-assisted surgery. In line with earlier reports, no statistically significant differences were detected between robot-assisted and laparoscopic procedures in intraoperative blood loss, infusion volume, or transfusion rate, underscoring the safety profile of the robot-assisted approach [21, 26, 27]. Clinical experience further suggests distinct advantages of robotics for patients who have received chemoradiotherapy: the stable, high-definition view helps counteract smoke accumulation caused by mesorectal edema, facilitating precise dissection; the enhanced instrument articulation allows smoother intersphincteric dissection in ultralow rectal cancers, thereby improving sphincter preservation; and the ability to perform intracorporeal suturing in narrow pelvic spaces makes reinforcement of ultralow anastomoses more readily achievable.
Because the robot-assisted system must be docked after anesthesia induction and before the first incision, a clinically acceptable prolongation of operative time was noted in the robot-assisted cohort both before and after PSM. This difference may also stem from the inclusion of early robot-assisted cases in which surgeons were still adapting to the learning curve; as proficiency increases, operative durations are expected to converge [28, 29]. With respect to perioperative morbidity, earlier studies of rectal cancer—whether or not neoadjuvant therapy was administered—have demonstrated that robot-assisted surgery was not associated with higher complication rates than laparoscopy [30, 31]. The present cohort of patients receiving neoadjuvant chemoradiotherapy confirms these observations, further substantiating the safety profile of the robot-assisted approach and echoing prior reports focused on this subgroup [32, 33].
The interpretation of the oncologic findings deserves particular caution. In the matched cohort, overall DFS was not significantly different, whereas OS appeared more favorable in the robot-assisted group. Although this pattern is possible, it should not be interpreted as evidence of a clear oncologic survival advantage of robot-assisted surgery. Given the limited number of disease-related deaths, the presence of non-cancer-related deaths, and the potential influence of post-recurrence treatment, surveillance intensity, follow-up imbalance, and residual confounding, the observed OS signal may reflect multiple non-causal factors rather than a direct survival benefit attributable to surgical approach alone. In addition, the reported 5-year OS and DFS values are actuarial estimates derived from Kaplan–Meier analysis, and the median follow-up of 35 months indicates that the maturity of the survival data remains limited, particularly for patients treated in the later years of the study period. An exploratory subgroup analysis of DFS was performed across 10 clinicopathological variables after PSM. In female patients, laparoscopic surgery was associated with a higher risk of recurrence or death than robotic surgery; however, this sex-specific analysis was not pre-specified, and no formal adjustment for multiple comparisons was performed. Therefore, this finding should be regarded as exploratory and hypothesis-generating rather than confirmatory evidence of a true sex-specific treatment effect.
Several limitations should be acknowledged. First, as a single-centre retrospective analysis, the study is inherently susceptible to selection bias, and, despite PSM, differences in unrecorded factors, including post-recurrence second-line therapies, may have influenced the OS comparison. Second, although the matching strategy was appropriately based on preoperative variables from a treatment-decision perspective, postoperative pathological factors were not part of the original matching model. Residual imbalance in such variables, particularly TRG, may reflect differences in treatment response or underlying disease biology; therefore, residual confounding affecting long-term survival interpretation cannot be completely excluded, even after exploratory sensitivity analyses incorporating TRG. Third, complete and standardized post-NCRT clinical restaging data, including ycT and ycN, were not consistently available in this retrospective cohort, which limited our ability to incorporate these post-treatment variables into matching or sensitivity analyses. Although treatment response was partly reflected by TRG, this postoperative pathological variable is not equivalent to standardized post-treatment clinical restaging. Fourth, patients with dMMR/MSI-H tumors were not routinely managed within the conventional NCRT pathway evaluated in the present study during the study period, and restriction to pMMR/MSS tumors was intended to maintain greater biological and therapeutic homogeneity; similarly, restriction to ASA I–II reflected the characteristics of the elective minimally invasive surgical population in this cohort. These design choices may limit generalizability. Fifth, the additional costs associated with robot-assisted surgery were not assessed. Finally, the cohort excluded individuals who underwent abdominoperineal resection, and postoperative bowel function and quality-of-life outcomes were not examined, precluding a comprehensive appraisal of any sphincter-preservation advantage afforded by robotics. Future investigations should incorporate multicenter, prospective data sets to verify the robustness of these findings.
In summary, in this single-center cohort of rectal cancer patients treated with neoadjuvant chemoradiotherapy, robot-assisted surgery showed broadly similar perioperative outcomes and comparable long-term disease-free survival to laparoscopic surgery. An apparent OS difference was observed in Kaplan–Meier analysis; however, this finding was attenuated in the primary preoperative covariate-adjusted Cox model and should be interpreted cautiously given the limited maturity of the survival data and the potential for residual confounding.
Supplementary Information
Acknowledgements
We sincerely appreciate the assistance of all colleagues from the Colorectal Department of the Sun Yat-sen University Cancer Center in this study.
Clinical trial number
Not applicable.
Authors’ contributions
Conception and design: Jianhong Peng, Zhizhong Pan. Financial support: Jianhong Peng, Zhizhong Pan and Peirong Ding. Provision of study materials or patients: Peirong Ding, Zhenhai Lu, Xiaojun Wu, Junzhong Lin, Yuan Li and Jinghua Tang. Collection and assembly of data: Weili Zhang, Weifeng Wang, Yingting Situ and Ruowei Wang. Data analysis and interpretation: Weili Zhang, Jianhong Peng. Manuscript writing: Weili Zhang, Jianhong Peng. All authors read and approved the final manuscript.
Funding
This study was supported by the Guangdong Basic and Applied Basic Research Foundation (2025A1515012742), Beijing Xisike Clinical Oncology Research Foundation (Y-Young2022–0023 and Y-Gilead2024-PT-0006).
Data availability
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. The authenticity of this article has been validated by uploading the key raw data onto the Research Data Deposit public platform (www. researchdata.org.cn)，RDD number RDDA2024411157.
Declarations
Ethics approval and consent to participate
All procedures conducted in studies involving human participants and human materials were approved by the Ethics Committee of Sun Yat-sen University Cancer Center (B2024-331). The study strictly adhered to the principles outlined in the Declaration of Helsinki and its subsequent amendments, or comparable ethical standards. Written informed consent to participate was obtained from all participants included in the study.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Weili Zhang, Jianhong Peng and Yingting Situ contributed equally to this work.
Contributor Information
Junzhong Lin, Email: linjzh@sysucc.org.cn.
Peirong Ding, Email: dingpr@sysucc.org.cn.
Zhizhong Pan, Email: panzhzh@sysucc.org.cn.
References
- 1.Benson AB, Venook AP, Adam M, et al. NCCN guidelines® insights: rectal cancer, version 3.2024. J Natl Compr Canc Netw. 2024;22(6):366–75. [DOI] [PubMed] [Google Scholar]
- 2.Glimelius B, Påhlman L, Cervantes A. Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol : Official JEur Soc Med Oncol. 2010;21(Suppl 5):v82-86. [DOI] [PubMed] [Google Scholar]
- 3.Aliseda D, Arredondo J, Sánchez-Justicia C, et al. Survival and safety after neoadjuvant chemotherapy or upfront surgery for locally advanced colon cancer: meta-analysis. Br J Surg. 2024;111(2):znae021. 10.1093/bjs/znae021. [DOI] [PMC free article] [PubMed]
- 4.Dijkstra EA, Nilsson PJ, Hospers GAP, et al. Locoregional failure during and after short-course radiotherapy followed by chemotherapy and surgery compared with long-course chemoradiotherapy and surgery: a 5-year follow-up of the RAPIDO trial. Ann Surg. 2023;278(4):e766–72. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Conroy T, Castan F, Etienne PL, et al. Total neoadjuvant therapy with mFOLFIRINOX versus preoperative chemoradiotherapy in patients with locally advanced rectal cancer: long-term results of the UNICANCER-PRODIGE 23 trial. Ann Oncol: Official J Eur Soc Med Oncol. 2024;35(10):873–81. [DOI] [PubMed] [Google Scholar]
- 6.Kasi A, Abbasi S, Handa S, et al. Total neoadjuvant therapy vs standard therapy in locally advanced rectal cancer: a systematic review and meta-analysis. JAMA Netw Open. 2020;3(12):e2030097. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Denost Q, Moreau JB, Vendrely V, et al. Intersphincteric resection for low rectal cancer: the risk is functional rather than oncological. A 25-year experience from Bordeaux. Colorectal Dis. 2020;22(11):1603–13. [DOI] [PubMed] [Google Scholar]
- 8.Williams H, Fokas E, Diefenhardt M, et al. Survival among patients treated with total mesorectal excision or selective watch-and-wait after total neoadjuvant therapy: a pooled analysis of the CAO/ARO/AIO-12 and OPRA randomized phase II trials. Ann Oncol: Official J Eur Soc Med Oncol. 2025;36(5):543–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.van der Valk MJM, Hilling DE, Bastiaannet E, et al. Long-term outcomes of clinical complete responders after neoadjuvant treatment for rectal cancer in the International Watch & Wait Database (IWWD): an international multicentre registry study. Lancet (London, England). 2018;391(10139):2537–45. [DOI] [PubMed] [Google Scholar]
- 10.Gaedcke J, Sahrhage M, Ebeling M, et al. Prognosis and quality of life in patients with locally advanced rectal cancer after abdominoperineal resection in the CAO/ARO/AIO-04 randomized phase 3 trial. Sci Rep. 2025;15(1):5401. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Lefevre JH, Mineur L, Kotti S, et al. Effect of interval (7 or 11 weeks) between neoadjuvant radiochemotherapy and surgery on complete pathologic response in rectal cancer: a multicenter, randomized, controlled trial (GRECCAR-6). J Clin Oncol. 2016;34(31):3773–80. [DOI] [PubMed] [Google Scholar]
- 12.Temmink SJD, Peeters K, Nilsson PJ, Martling A, van de Velde CJH. Surgical Outcomes after Radiotherapy in Rectal Cancer. Cancers. 2024;16(8). 10.3390/cancers16081539. [DOI] [PMC free article] [PubMed]
- 13.Jäger T, Zitt M, Riss S, et al. Does Total Neoadjuvant Therapy Impact Surgical Precision in Total Mesorectal Excision? A Nationwide Survey of the Experiences of Expert Surgeons. Cancers. 2025;17(2). 10.3390/cancers17020283. [DOI] [PMC free article] [PubMed]
- 14.Jiang W, Xu J, Cui M, et al. Laparoscopy-assisted versus open surgery for low rectal cancer (LASRE): 3-year survival outcomes of a multicentre, randomised, controlled, non-inferiority trial. Lancet Gastroenterol Hepatol. 2025;10(1):34–43. [DOI] [PubMed] [Google Scholar]
- 15.Kearney DE, Coffey JC. A Randomized Trial of Laparoscopic versus Open Surgery for Rectal Cancer. N Engl J Med. 2015;373(2):194. [DOI] [PubMed] [Google Scholar]
- 16.van der Pas MH, Haglind E, Cuesta MA, et al. Laparoscopic versus open surgery for rectal cancer (COLOR II): short-term outcomes of a randomised, phase 3 trial. Lancet Oncol. 2013;14(3):210–8. [DOI] [PubMed] [Google Scholar]
- 17.Chen E, Chen L, Zhang W. Robotic-assisted colorectal surgery in colorectal cancer management: a narrative review of clinical efficacy and multidisciplinary integration. Front Oncol. 2025;15:1502014. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Peng J, Zhang W, Li W, et al. Comparison of robotic and laparoscopic surgery for sigmoid colon and rectal cancer: a single-center retrospective study on surgical outcomes and long-term survival. J Robot Surg. 2024;18(1):299. [DOI] [PubMed] [Google Scholar]
- 19.Jayne D, Pigazzi A, Marshall H, et al. Effect of Robotic-Assisted vs Conventional Laparoscopic Surgery on Risk of Conversion to Open Laparotomy Among Patients Undergoing Resection for Rectal Cancer: The ROLARR Randomized Clinical Trial. JAMA. 2017;318(16):1569–80. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Prete FP, Pezzolla A, Prete F, et al. Robotic versus laparoscopic minimally invasive surgery for rectal cancer: a systematic review and meta-analysis of randomized controlled trials. Ann Surg. 2018;267(6):1034–46. [DOI] [PubMed] [Google Scholar]
- 21.Feng Q, Yuan W, Li T, et al. Robotic versus laparoscopic surgery for middle and low rectal cancer (REAL): short-term outcomes of a multicentre randomised controlled trial. Lancet Gastroenterol Hepatol. 2022;7(11):991–1004. [DOI] [PubMed] [Google Scholar]
- 22.Pigazzi A, Ellenhorn JD, Ballantyne GH, Paz IB. Robotic-assisted laparoscopic low anterior resection with total mesorectal excision for rectal cancer. Surg Endosc. 2006;20(10):1521–5. [DOI] [PubMed] [Google Scholar]
- 23.von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet (London, England). 2007;370(9596):1453–7. [DOI] [PubMed] [Google Scholar]
- 24.Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 2004;240(2):205–13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Rahbari NN, Weitz J, Hohenberger W, et al. Definition and grading of anastomotic leakage following anterior resection of the rectum: a proposal by the International Study Group of Rectal Cancer. Surgery. 2010;147(3):339–51. [DOI] [PubMed] [Google Scholar]
- 26.Ricciardi R, Seshadri-Kreaden U, Yankovsky A, et al. The COMPARE Study: Comparing Perioperative Outcomes of Oncologic Minimally Invasive Laparoscopic, da Vinci Robotic, and Open Procedures: A Systematic Review and Meta-analysis of the Evidence. Ann Surg. 2025;281(5):748–63. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Zhang C, Tan H, Xu H, Ding J. The role of robotic-assisted surgery in the management of rectal cancer: a systematic review and meta-analysis. Int J Surg (London, England). 2024;110(10):6282–96. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Foo CC, Law WL. The learning curve of robotic-assisted low rectal resection of a novice rectal surgeon. World J Surg. 2016;40(2):456–62. [DOI] [PubMed] [Google Scholar]
- 29.Kayano H, Okuda J, Tanaka K, Kondo K, Tanigawa N. Evaluation of the learning curve in laparoscopic low anterior resection for rectal cancer. Surg Endosc. 2011;25(9):2972–9. [DOI] [PubMed] [Google Scholar]
- 30.Duhoky R, Geitenbeek RTJ, Niccolò Piozzi G, et al. Ten years of robot-assisted versus laparoscopic total mesorectal excision for rectal cancer (short-term RESOLUTION). J Natl Cancer Inst. 2025;117(8):1614–26. [DOI] [PubMed] [Google Scholar]
- 31.Zou J, Zhu H, Tang Y, Huang Y, Chi P, Wang X. Robotic versus laparoscopic surgery for rectal cancer: an updated systematic review and meta-analysis of randomized controlled trials. BMC Surg. 2025;25(1):86. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Zhu XM, Bai X, Wang HQ, Dai DQ. Comparison of efficacy and safety between robotic-assisted versus laparoscopic surgery for locally advanced mid-low rectal cancer following neoadjuvant chemoradiotherapy: a systematic review and meta-analysis. Int J Surg. 2025;111(1):1154–66. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Lim DR, Bae SU, Hur H, et al. Long-term oncological outcomes of robotic versus laparoscopic total mesorectal excision of mid-low rectal cancer following neoadjuvant chemoradiation therapy. Surg Endosc. 2017;31(4):1728–37. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. The authenticity of this article has been validated by uploading the key raw data onto the Research Data Deposit public platform (www. researchdata.org.cn)，RDD number RDDA2024411157.