Total mesorectal excision with or without preoperative chemoradiotherapy for resectable mid/low rectal cancer: a long-term analysis of a prospective, single-center, randomized trial

Efficacies of radiotherapy in rectal cancer patients treated with total mesorectal excision or other types of surgery: an updated meta-analysis

Background

An updated meta-analysis was conducted to evaluate the efficacy of radiotherapy in rectal cancer patients treated with total mesorectal excision (TME) or other types of surgery (non-TME-only).

Methods

The PubMed, Cochrane Library, and CNKI databases were searched. Data on overall survival (OS) were extracted.

Results

Hazard ratios (HRs) for OS associated with preoperative radiotherapy, preoperative long-course concurrent chemoradiotherapy (LCCRT), preoperative radiotherapy alone, and postoperative radiotherapy in patients treated with TME were 1.02 [95% CI: 0.92-1.14, P = 0.65], 1.04 [95% CI: 0.93-1.16, P = 0.47], 0.87 [95% CI: 0.61-1.25, P = 0.46], and 1.18 [95% CI: 0.91-1.52, P = 0.20], respectively. HRs for OS associated with preoperative radiotherapy, preoperative LCCRT, preoperative radiotherapy alone, preoperative long-course RT (LCRT), and preoperative short-course radiotherapy (SCRT) in patients treated with non-TME-only surgery were 0.85 [95% CI: 0.79-0.90, P < 0.00001], 0.77 [95% CI: 0.63-0.94, P = 0.009], 0.86 [95% CI: 0.80-0.92, P < 0.0001], 0.83 [95% CI: 0.73-0.95, P = 0.005], and 0.84 [95% CI: 0.77-0.91, P= <0.0001], respectively. The HR for postoperative radiotherapy in patients treated with non-TME-only surgery was 1.08 [95% CI: 0.84-1.39, P = 0.57].

Conclusion

Preoperative radiotherapy, regardless of the regimen, improves the OS in patients treated with non-TME-only surgery, but not in those treated with TME. Postoperative radiotherapy does not improve OS.

Advances in knowledge

This meta-analysis will serve as a reference for decision-making in multidisciplinary approaches for rectal cancer patients.

Neoadjuvant Radiotherapy vs Up-Front Surgery for Resectable Locally Advanced Rectal Cancer

Importance

Guidelines for resectable locally advanced rectal cancer (LARC) advocate for neoadjuvant radiotherapy (NRT) followed by surgery as the standard approach. However, recent trials have reported no oncological benefits of NRT-based therapy for middle or lower rectal cancer, raising the question of whether NRT followed by surgery remains the optimal treatment approach for resectable LARC overall.

Objective

To compare the outcomes of NRT followed by surgery vs up-front surgery for resectable LARC.

Design, Setting, and Participants

This cohort study, using a target trial emulation framework with nationwide registries in Taiwan, included patients undergoing curative resection for resectable LARC (cT1-2N1-2, cT3Nany) between January 1, 2014, and December 31, 2017, with follow-up until December 31, 2020. Data were analyzed from January 1, 2024, to February 15, 2025.

Exposure

NRT.

Main Outcomes and Measures

The primary outcomes were overall survival (OS) and local recurrence (LR). The secondary outcome was intraoperative diverting stoma outcomes.

Results

A total of 4099 patients were analyzed, including 1436 patients undergoing NRT followed by surgery (median [IQR] age, 62.0 [53.0-71.0] years; 1036 [72.1%] male) and 2663 patients undergoing up-front surgery (median [IQR] age, 65.0 [56.0-74.0] years; 1626 [61.1%] male). NRT followed by surgery, compared with up-front surgery, was associated with higher 3-year OS rates (88.5% vs 85.2%; hazard ratio [HR], 0.74; 95% CI, 0.59-0.92) but higher permanent diverting stoma rates (20.6% vs 11.1%; relative risk [RR], 1.91; 95% CI, 1.62-2.25); LR rates were not significantly different (5.7% vs 6.6%; HR, 0.78; 95% CI, 0.55-1.11). Subgroup analysis revealed that compared with up-front surgery, NRT followed by surgery was associated with improved outcomes in middle or lower rectal cancer but not upper rectal cancer (OS: HR, 1.54; 95% CI, 0.82-2.90; LR: HR, 1.08; 95% CI, 0.23-5.00). NRT followed by surgery was associated with significantly increased risks of permanent diverting stomas across different tumor heights, particularly in upper rectal cancer (RR, 3.54; 95% CI, 1.44-8.69).

Conclusions and Relevance

In this cohort study of nationwide registries in Taiwan, NRT followed by surgery was associated with improved oncological outcomes for overall resectable LARC, with excessive diverting stoma nonreversal as the trade-off. However, the benefits of NRT were not observed for upper rectal cancer. These findings raise concerns about potential harm from NRT and advise caution when performing NRT for upper rectal cancer.

Effect of neoadjuvant chemoradiotherapy with or without PD-1 antibody sintilimab in pMMR locally advanced rectal cancer: A randomized clinical trial

Neoadjuvant chemoradiotherapy (NACRT) was the standard treatment for patients with locally advanced rectal cancer (LARC) with proficient mismatch repair (pMMR) proteins. In this randomized phase 2 trial (ClinicalTrial.gov: NCT04304209), 134 pMMR LARC patients were randomly (1:1) assigned to receive NACRT or NACRT and the programmed cell death protein 1 (PD-1) antibody sintilimab. As the primary endpoint, the total complete response (CR) rate is 26.9% (18/67, 95% confidence interval [CI] 16.0%-37.8%) and 44.8% (30/67, 95% CI 32.6%-57.0%) in the control and experimental arm, respectively, with significant difference (p = 0.031 for chi-squared test). Response ratio is 1.667 (95% CI 1.035-2.683). Immunohistochemistry shows PD-1 ligand 1 (PD-L1) combined positive score is associated with the synergistic effect. The safety profile is similar between the arms. Adding the PD-1 antibody sintilimab to NACRT significantly increases the CR rate in pMMR LARC, with a manageable safety profile. PD-L1 positivity may help identify patients who might benefit most from the combination therapy.

Assessing neoadjuvant therapy recommendations in 19 national and international guidelines for rectal cancer

BACKGROUND

 Treatment guidelines belong to the most authoritative sources of evidence-based medicine and are widely implemented by health-care providers. Rectal cancer with an annual incidence of over 730,000 new cases and nearly 340,000 deaths worldwide, remains a significant therapeutic challenge. The total mesorectal excision (TME) leads to a dramatic improvement of local control. The addition of neoadjuvant treatment has been proposed to offer further advancement. However, this addition results in significant functional impairment and a decline in the quality of life.

METHODS

This review critically assesses whether the recommendation for neoadjuvant treatment in current international guidelines is substantiated. A comprehensive search was conducted in July 2022 in PubMed resulting in 988 papers published in English between 2012 and 2022. After exclusions and proofs 19 documents remained for further analysis.

RESULTS

Of the 19 guidelines considered in this review, 11 do not recommend upfront surgery, and 12 do not address the issue of functional impairment following multimodal treatment. The recommendation for neoadjuvant therapy relies on outdated references, lacking differentiated strategies based on current utilisation of MRI staging; numerous guidelines recommend neoadjuvant treatment also to subgroups of patients, who may not need this therapy. Also statements regarding conflicts of interest are often not presented.

CONCLUSIONS

An immediate and imperative step is warranted to align the recommendations with the latest available evidence, thereby affording rectal cancer patients a commensurate standard of care. A meticulous assessment of the guideline formulation process has the potential to avert heterogeneity in the future.

Survival prognostic in different age groups of patients undergoing local versus radical excision for rectal cancer: a study based on the SEER database

Age significantly affects the prognosis of patients with rectal cancer after radical excision (RE), and local excision (LE) is an alternative surgical procedure to RE. To compare the survival prognosis in different age groups of LE versus RE for rectal cancer. Patients diagnosed with rectal adenocarcinoma treated by LE or RE from 2010 to 2017 were obtained from the SEER database. The primary outcomes are 5-year OS and CSS. A total of 11,170 patients were eventually included, and there were 490 patients in LE and RE groups, respectively, after 1:1 propensity score matching. The 5-year OS and CSS after LE were significantly better in < 50 years and 50-66 years groups than in > 66 years group (5-year OS: 95.70% vs 88.40% vs 67.00%, P < 0.001; 5-year CSS: 95.70% vs 96.30% vs 82.60%, P < 0.001). No statistical significance was found for the differences in 5-year OS and CSS between LE and RE in < 50, 50-66, and > 66 years group (P > 0.05). Multivariate analysis showed age > 66 years, poorly differentiated or undifferentiated (Grade III/IV), and tumor size 3 to 5 cm was independent risk factors for 5-year OS after LE; age > 66 years, perineural invasion, and tumor size 3 to 5 cm were the 5-year CSS independent risk factors for after LE. We found that the survival prognosis of younger rectal cancer patients treated with LE was significantly better than older (> 66 years) patients, and the survival prognosis of rectal cancer patients in the three age groups was similar between LE and RE.

Quality of Surgical Outcome Reporting in Randomised Clinical Trials of Multimodal Rectal Cancer Treatment: A Systematic Review

INTRODUCTION

Randomised controlled trials (RCTs) continue to provide the best evidence for treatment options, but the quality of reporting in RCTs and the completeness rate of reporting of surgical outcomes and complication data vary widely. The aim of this study was to measure the quality of reporting of the surgical outcome and complication data in RCTs of rectal cancer treatment and whether this quality has changed over time.

METHODS

Eligible articles with the keywords ("rectal cancer" OR "rectal carcinoma") AND ("radiation" OR "radiotherapy") that were RCTs and published in the English, German, Polish, or Italian language were identified by reviewing all abstracts published from 1982 through 2022. Two authors independently screened and analysed all studies. The quality of the surgical outcome and complication data was assessed based on fourteen criteria, and the quality of RCTs was evaluated based on a modified Jadad scale. The primary outcome was the quality of reporting in RCTs and the completeness rate of reporting of surgical results and complication data.

RESULTS

A total of 340 articles reporting multimodal therapy outcomes for 143,576 rectal cancer patients were analysed. A total of 7 articles (2%) met all 14 reporting criteria, 13 met 13 criteria, 27 met from 11 to 12 criteria, 36 met from 9 to 10 criteria, 76 met from 7 to 8 criteria, and most articles met fewer than 7 criteria (mean 5.5 criteria). Commonly underreported criteria included complication severity (15% of articles), macroscopic integrity of mesorectal excision (17% of articles), length of stay (18% of articles), number of lymph nodes (21% of articles), distance between the tumour and circumferential resection margin (CRM) (26% of articles), surgical radicality according to the site of the primary tumour (R0 vs. R1 + R2) (29% of articles), and CRM status (38% of articles).

CONCLUSION

Inconsistent surgical outcome and complication data reporting in multimodal rectal cancer treatment RCTs is standard. Standardised reporting of clinical and oncological outcomes should be established to facilitate comparing studies and results of related research topics.

Total neoadjuvant treatment to increase the clinical complete response rate for distal locally advanced rectal cancer (TESS): A study protocol of a prospective, open-label, multicenter, single-arm, phase 2 trial

BACKGROUND

Standard treatment of locally advanced rectal cancer (LARC) was neoadjuvant chemoradiotherapy (CRT), followed by total mesorectal excision (TME). Total neoadjuvant treatment (TNT), a new concept, attempts to deliver both systemic chemotherapy and neoadjuvant CRT prior to surgery. Patients treated with neoadjuvant chemotherapy were more likely to show higher tumor regression. The objective of this trial was to increase complete clinical rate (cCR) for LARC patients by optimizing tumor response, using TNT regimen as compared to conventional chemoradiotherapy. TESS, a prospective, open-label, multicenter, single-arm, phase 2 study, is underway.

METHODS

Main inclusion criteria include cT3-4aNany or cT1-4aN+ rectal adenocarcinoma aged 18-70y; Eastern Cooperative Oncology Group (ECOG) performance 0-1; location ≤5 cm from anal verge. Ninety-eight patients will receive 2 cycles of neoadjuvant chemotherapy Capeox (capecitabine + oxaliplatin) before, during, and after radiotherapy 50Gy/25 fractions, before TME (or other treatment decisions, such as Watch and Wait strategy) and adjuvant chemotherapy capecitabine 2 cycles. Primary endpoint is the cCR rate. Secondary endpoints include ratio of sphincter preservation strategy; pathological complete response rate and tumor regression grade distribution; local recurrence or metastasis; disease-free survival; locoregional recurrence-free survival; acute toxicity; surgical complications; long-term anal function; late toxicity; adverse effect, ECOG standard score, and quality of life. Adverse events are graded per Common Terminology Criteria for Adverse Events V5.0. Acute toxicity will be monitored during antitumor treatment, and late toxicity will be monitored for 3 years from the end of the first course of antitumor treatment.

DISCUSSION

The TESS trial aims to explore a new TNT strategy, which is expected to increase the rate of cCR and sphincter preservation rate. This study will provide new options and evidence for a new sandwich TNT strategy in patients with distal LARC.

A systematic review and network meta-analysis of randomised controlled trials comparing neoadjuvant treatment strategies for stage II and III rectal cancer

AIM

Multiple neoadjuvant therapy strategies have been used and compared for rectal cancer and there has been no true consensus as to the optimal neoadjuvant therapy regimen. The aim is to identify and compare the neoadjuvant therapies available for stage II and III rectal cancer.

DESIGN

A systematic literature review was performed, from inception to August 2022, of the following databases: MEDLINE, EMBASE, Science Citation Index Expanded, Cochrane Library. Only randomized controlled trials comparing neoadjuvant therapies for stage II and III rectal cancer were considered. Stata was used to draw network plots, and a Bayesian network meta-analysis was conducted through models utilizing the Markov Chain Monte Carlo method in WinBUGS.

RESULTS

A total of 58 articles were included based on 41 randomised controlled trials, reporting on 12,404 participants that underwent 15 neoadjuvant treatment regimens. No significant difference was identified between treatments for major or total postoperative complications, anastomotic leak rates, or sphincter-saving surgery. Straight to surgery (STS) ranked as best treatment for preoperative toxicity but ranked worst treatment for positive resection margins and complete response. STS had significantly increased positive resection margins compared to long-course chemoradiotherapy with short-wait (LCCRT-SW) or long-wait (LCCRT-LW) to surgery, or short-course radiotherapy with short-wait (SCRT-SW) or immediate surgery (SCRT-IS). LCCRT-SW or LCCRT-LW resulted in significantly increased complete response rates compared to STS. LCCRT-LW significantly improved 2-year overall survival compared to STS, SCRT-IS, SCRT-SW. Total neoadjuvant therapy regimes with short-course radiotherapy followed by consolidation chemotherapy (SCRT-CT-SW), induction chemotherapy followed by long-course chemoradiotherapy (CT-LCCRT-S), long-course chemoradiotherapy followed by consolidation chemotherapy (LCCRT-CT-S), significantly improved positive resection margins, complete response, and disease-free survival compared to STS. Chemotherapy with monoclonal antibodies followed by long-course chemoradiotherapy (CT+MAB-LCCRT+MAB-S) significantly improved complete response and positive resection margins compared to STS, and 2-year disease-free survival compared to STS, SCRT-IS, SCRT-SW, SCRT-CT-SW, LCCRT-SW, LCCRT-LW. CT+MAB-LCCRT+MAB-S ranked as best treatment for disease-free survival and overall survival.

CONCLUSIONS

Conventional neoadjuvant therapies with short-course radiation or long-course chemoradiotherapy have oncological benefits compared to no neoadjuvant therapy without increasing perioperative complication rates. Prolonged wait to surgery may improve oncological outcomes. Total neoadjuvant therapies provide additional benefits in terms of complete response, positive resection margins, and disease-free survival. Monoclonal antibody therapy may further improve oncological outcomes but currently is only applicable to a small subgroup of patients and requires further validation.

Impact of Value Frameworks on the Magnitude of Clinical Benefit: Evaluating a Decade of Randomized Trials for Systemic Therapy in Solid Malignancies

In the era of rapid development of new, expensive cancer therapies, value frameworks have been developed to quantify clinical benefit (CB). We assessed the evolution of CB since the 2015 introduction of The American Society of Clinical Oncology and The European Society of Medical Oncology value frameworks. Randomized clinical trials (RCTs) assessing systemic therapies for solid malignancies from 2010 to 2020 were evaluated and CB (Δ) in 2010–2014 (pre-value frameworks (PRE)) were compared to 2015–2020 (POST) for overall survival (OS), progression-free survival (PFS), response rate (RR), and quality of life (QoL). In the 485 studies analyzed (12% PRE and 88% POST), the most common primary endpoint was PFS (49%), followed by OS (20%), RR (12%), and QoL (6%), with a significant increase in OS and decrease in RR as primary endpoints in the POST era (p = 0.011). Multivariable analyses revealed significant improvement in ΔOS POST (OR 2.86, 95% CI 0.46 to 5.26, p = 0.02) while controlling for other variables. After the development of value frameworks, median ΔOS improved minimally. The impact of value frameworks has yet to be fully realized in RCTs. Efforts to include endpoints shown to impact value, such as QoL, into clinical trials are warranted.

Efficacy of Neoadjuvant Therapy in Improving Long-Term Survival of Patients with Resectable Rectal Cancer: A Meta-Analysis

BACKGROUND

The impact of neoadjuvant therapy on long-term prognosis of patients with resectable rectal cancer is currently unknown.

OBJECTIVE

This study aimed to explore the long-term prognosis of patients with resectable rectal cancer following treatment with neoadjuvant therapy.

METHODS

Four major databases (PubMed, Web of Science, Embase, Cochrane library) were searched to identify relevant articles published between January 2000 and July 2020. The main outcome indicators were the 5-year overall survival (OS) and disease-free survival (DFS).

RESULTS

The meta-analysis revealed that 5-year OS (HR: 0.88, 95% Cl: 0.83-0.93) and DFS (HR: 0.95, 95% Cl: 0.91-0.98) were higher in patients with resectable rectal cancer after receiving neoadjuvant therapy than those treated with upfront surgery. Subgroup analysis demonstrated that the long-term survival of patients in Asia and Europe could benefit from neoadjuvant therapy. The neoadjuvant short-course radiotherapy (SCRT) and neoadjuvant chemo-radiotherapy (CRT) improved the 5-year OS and DFS of patients with stage Ⅱ-Ⅲ rectal cancer and mid/low rectal cancer. Further research found that patients with stage Ⅱ only had an increase in OS, while patients with stage Ⅲ have improved 5-year OS and DFS.

CONCLUSION

Neoadjuvant therapy improved the long-term survival of patients with mid/low rectal cancer in stage Ⅱ-Ⅲ (especially stage Ⅲ). Additionally, patients in Asia and Europe seemed to be more likely to benefit from neoadjuvant therapy. For the treatment, we recommend neoadjuvant SCRT and neoadjuvant CRT for resectable rectal cancer.

Role of 18F-PET-CT to predict pathological response after neoadjuvant treatment of rectal cancer

OBJECTIVES

Neoadjuvant chemoradiation (nCRT) is universally considered to be a valid treatment to achieve downstaging, to improve local disease control and to obtain better resectability in locally advanced rectal cancer (LARC). The aim of this study is to correlate the change in the tumour 18F-FDG PET-CT standardized uptake value (SUV) before and after nCRT, in order to obtain an early prediction of the pathologic response (pR) achieved in patients with LARC.

DATA DESCRIPTION

We performed a retrospective analysis of patients with LARC diagnosis who underwent curative resection. All patients underwent a baseline 18F-FDG PET-CT scan within the week prior to the initiation of the treatment (PET-CT SUV1) and a second scan (PET-CT SUV2) within 6 weeks of the completion of nCRT. We evaluated the prognostic value of 18F-FDG PET-CT in terms of disease-free survival (DFS) and overall survival (OS) in patients with LARC.A total of 133 patients with LARC were included in the study. Patients were divided in two groups according to the TRG (tumour regression grade): 107 (80%) as the responders group (TRG0-TRG1) and 26 (25%) as the no-responders group (TRG2-TRG3). We obtained a significant difference in Δ%SUV between the two different groups; responders versus no-responders (p < 0.012). The results of this analysis show that 18F-FDG PET-CT may be an indicator to evaluate the pR to nCRT in patients with LARC. The decrease in 18F-FDG PET-CT uptake in the primary tumour may offer important information in order for an early identification of those patients more likely to obtain a pCR to nCRT and to predict those who are unlikely to significantly regress.

MRI-defined high-risk rectal cancer patients: outcome comparison between neoadjuvant chemoradiotherapy plus TME and TME plus adjuvant chemotherapy or TME alone

OBJECTIVE

The goal of this study was to investigate whether neoadjuvant chemoradiotherapy (NCRT) plus total mesorectal excision (TME) would improve the outcome of patients with MRI-defined high-risk rectal cancer compared with TME plus adjuvant chemotherapy (ACT) or TME alone.

METHODS

We retrospectively enrolled 362 patients with MRI-defined high-risk rectal cancer who were treated with NCRT plus TME, TME plus ACT, or TME alone between January 2008 and August 2018. Cases with a high-risk tumor stage, positive extramural venous invasion, or mesorectal fascia involvement on baseline MRI were considered cases of high-risk rectal cancer. We matched patients treated with NCRT plus TME to patients treated with TME plus ACT and to those treated with TME alone. Kaplan-Meier curves were used to compare local recurrence (LR), disease-free survival (DFS), and overall survival (OS) rates.

RESULTS

The cumulative 3 year LR rate in the matched NCRT plus TME group was more favorable than in the TME plus ACT group (0% vs 5.1%; p = 0.037; n = 98) and in the TME alone group (0% vs 11.5%; p = 0.016; n = 61). Patients who received NCRT plus TME demonstrated better cumulative 3 year DFS rates than patients treated with TME plus ACT (85.7% vs 65.3%; p = 0.009) or with TME alone (86.9% vs 68.9%; p = 0.046). No difference in OS was observed among the groups.

CONCLUSION

NCRT may improve DFS and LR rates in patients with MRI-defined high-risk rectal cancer when compared with TME plus ACT or TME alone.

ADVANCES IN KNOWLEDGE

This study illustrated the specific benefit of NCRT on the outcome measures of MRI-defined high-risk rectal cancer compared with TME plus ACT or TME alone, which was not clearly clarified in previous studies enrolling all patients with Stage II/III rectal cancer.

The watch-and-wait strategy versus surgical resection for rectal cancer patients with a clinical complete response after neoadjuvant chemoradiotherapy

Background

The watch-and-wait strategy offers a non-invasive therapeutic alternative for rectal cancer patients who have achieved a clinical complete response (cCR) after chemoradiotherapy. This study aimed to investigate the long-term clinical outcomes of this strategy in comparation to surgical resection.

Methods

Stage II/III rectal adenocarcinoma patients who received neoadjuvant chemoradiotherapy and achieved a cCR were selected from the databases of three centers. cCR was evaluated by findings from digital rectal examination, colonoscopy, and radiographic images. Patients in whom the watch-and-wait strategy was adopted were matched with patients who underwent radical resection through 1:1 propensity score matching analyses. Survival was calculated and compared in the two groups using the Kaplan–Meier method with the log rank test.

Results

A total of 117 patients in whom the watch-and-wait strategy was adopted were matched with 354 patients who underwent radical resection. After matching, there were 94 patients in each group, and no significant differences in term of age, sex, T stage, N stage or tumor location were observed between the two groups. The median follow-up time was 38.2 months. Patients in whom the watch-and-wait strategy was adopted exhibited a higher rate of local recurrences (14.9% vs. 1.1%), but most (85.7%) were salvageable. Three-year non-regrowth local recurrence-free survival was comparable between the two groups (98% vs. 98%, P = 0.506), but the watch-and-wait group presented an obvious advantage in terms of sphincter preservation, especially in patients with a tumor located within 3 cm of the anal verge (89.7% vs. 41.2%, P < 0.001). Three-year distant metastasis-free survival (88% in the watch-and-wait group vs. 89% in the surgical group, P = 0.874), 3-year disease-specific survival (99% vs. 96%, P = 0.643) and overall survival (99% vs. 96%, P = 0.905) were also comparable between the two groups, although a higher rate (35.7%) of distant metastases was observed in patients who exhibited local regrowth in the watch-and-wait group.

Conclusion

The watch-and-wait strategy was safe, with similar survival outcomes but a superior sphincter preservation rate as compared to surgery in rectal cancer patients achieving a cCR after neoadjuvant chemoradiotherapy, and could be offered as a promising conservative alternative to invasive radical surgery.

Identification of the surgical indication line for the Denonvilliers' fascia and its anatomy in patients with rectal cancer

Background

The high rate of urogenital dysfunction after traditional total mesorectal excision (TME) has caused doubts among scholars on the standard fashion of dissection. We have proposed the necessity to preserve the Denonvilliers’ fascia in patients with rectal cancer. However, how to accurately locate the Denonvilliers’ fascia is unclear. This study aimed to explore anatomical features of the Denonvilliers’ fascia by comparing autopsy findings and observations of surgical videos so as to propose a dissection method for the preservation of pelvic autonomic nerves during rectal cancer surgery.

Methods

Five adult male cadaver specimens were dissected, and surgical videos of 135 patients who underwent TME for mid‐low rectal cancer between January 2009 and February 2019 were reviewed to identify and compare the structure of the Denonvilliers’ fascia.

Results

The monolayer structure of the Denonvilliers’ fascia was observed in 5 male cadaver specimens, and it was located between the rectum, the bottom of the bladder, the seminal vesicles, the vas deferens, and the prostate. The Denonvilliers’ fascia was originated from the rectovesical pouch (or rectum‐uterus pouch), down to fuse caudally with the rectourethral muscle at the apex of the prostate, and fused to the lateral ligaments on both sides. The fascia was thinner on the midline with a thickness of 1.06 ± 0.10 mm. The crown shape of the Denonvilliers’ fascia was slightly triangular, with a height of approximately 5.42 ± 0.16 cm at midline. Nerves were more densely distributed in front of the Denonvilliers’ fascia than behind, especially on both sides of it. Under laparoscopic view, the Denonvilliers’ fascia was originated at the lowest point of the rectovesical pouch (or rectum‐uterus pouch), with a thickened white line which was a good mark for identifying the Denonvilliers’ fascia.

Conclusion

Identification of the surgical indication line for the Denonvilliers’ fascia could help us identify the Denonvilliers’ fascia, and it would improve our ability to protect the pelvic autonomic function of patients undergoing TME for rectal cancer.