What is the risk of permanent stoma beyond 5 years after low anterior resection for rectal cancer? A 15-year follow-up of a randomized trial

Machine learning model for prediction of permanent stoma after anterior resection of rectal cancer: A multicenter study

BACKGROUND

The conversion from a temporary to a permanent stoma (PS) following rectal cancer surgery significantly impacts the quality of life of patients. However, there is currently a lack of practical preoperative tools to predict PS formation. The purpose of this study is to establish a preoperative predictive model for PS using machine learning algorithms to guide clinical practice.

METHODS

In this retrospective study, we analyzed clinical data from a total of 655 patients who underwent anterior resection for rectal cancer, with 552 patients from one medical center and 103 from another. Through machine learning algorithms, five predictive models were developed, and each was thoroughly evaluated for predictive performance. The model with superior predictive accuracy underwent additional validation using both an independent testing cohort and the external validation cohort. The Shapley Additive exPlanations (SHAP) approach was employed to elucidate the predictive factors influencing the model, providing an in-depth visual analysis of its decision-making process.

RESULTS

Eight variables were selected for the construction of the model. The support vector machine (SVM) model exhibited superior predictive performance in the training set, evidenced by an AUC of 0.854 (95 % CI:0.803-0.904). This performance was corroborated in both the testing set and external validation set, where the model demonstrated an AUC of 0.851 (95%CI:0.748-0.954) and 0.815 (95%CI:0.710-0.919), respectively, indicating its efficacy in identifying the PS.

CONCLUSIONS

The model(https://yangsu2023.shinyapps.io/psrisk/) indicated robust predictive performance in identifying PS after anterior resection for rectal cancer, potentially guiding surgeons in the preoperative stratification of patients, thus informing individualized treatment plans and improving patient outcomes.

Endoscopic resection of residual rectal neoplasia after definitive chemoradiotherapy for rectal cancer

The conventional approach to treating locally advanced rectal cancer, commonly defined as cT3 or cT4 primary tumors or with nodal metastases, involves chemoradiation (CRT) followed by surgical resection. There is a growing recognition of the potential for nonsurgical management following CRT or total neoadjuvant therapy (TNT), which allows for organ preservation. "Watch and wait" strategy may be considered if complete clinical response is achieved. In cases when adenoma or superficial cancer is present, a novel approach known as "salvage endoscopic resection of the residual disease" is emerging as a viable nonsurgical option for carefully selected patients. This review discusses available evidence and future potential for endoscopic management of residual neoplasia after oncological treatment of rectal cancer.

Permanent stoma rate and long-term stoma complications in laparoscopic, robot-assisted, and transanal total mesorectal excisions: a retrospective cohort study

BACKGROUND

The surgical resection of rectal carcinoma is associated with a high risk of permanent stoma rate. Primary anastomosis rate is suggested to be higher in robot-assisted and transanal total mesorectal excision, but permanent stoma rate is unknown.

METHODS

Patients undergoing total mesorectal excision for MRI-defined rectal cancer between 2015 and 2017 in 11 centers highly experienced in laparoscopic, robot-assisted or transanal total mesorectal excision were included in this retrospective study. Permanent stoma rate, stoma-related complications, readmissions, and reoperations were registered. A multivariable regression analysis was performed for permanent stoma rate, stoma-related complications, and stoma-related reoperations.

RESULTS

In total, 1198 patients were included. Permanent stoma rate after low anterior resection (with anastomosis or with an end colostomy) was 40.1% in patients undergoing laparoscopic surgery, 21.3% in patients undergoing robot-assisted surgery, and 25.6% in patients undergoing transanal surgery (P < 0.001). Permanent stoma rate after low anterior resection with an anastomosis was 17.3%, 11.8%, and 15.1%, respectively. The robot-assisted and transanal techniques were independently associated with a reduction in permanent stoma rate in patients who underwent a low anterior resection (with anastomosis or with an end colostomy) (OR 0.39 [95% CI 0.25, 0.59] and OR 0.35 [95% CI 0.22, 0.55]), while this was not seen in patients who underwent a restorative low anterior resection. 45.4% of the patients who had a stoma experienced stoma-related complications, 4.0% were at least once readmitted, and 8.9% underwent at least one reoperation.

CONCLUSIONS

The robot-assisted and transanal techniques are associated with a lower permanent stoma rate in patients who underwent a low anterior resection.

Risk Factors for Radical Rectal Cancer Surgery with a Temporary Stoma Becoming a Permanent Stoma: A Pooling Up Analysis

Purpose: The aim of this study was to find out the potential risk factors for the formation of a permanent stoma (PS) for rectal cancer patients with a temporary stoma (TS) after surgery. Methods: PubMed, Embase, and the Cochrane Library were searched for eligible studies until November 14, 2022. The patients were divided into the PS group and the TS group. Odds ratio (ORs) and 95% confidence intervals (CIs) were pooled up for describing dichotomous variables. Stata SE 16 was performed for data analysis. Results: After pooling up the data, a total of 14 studies involving 14,265 patients were included in this study. The outcomes showed that age (OR = 1.03, 95% CI = 0.96 to 1.10, I2 = 1.42%, P = .00 < .1), surgery type (P = .00 < .1), tumor stage (P = .00 < .1), preoperative chemoradiotherapy (P = .00 < .1), preoperative radiotherapy (P = .01 < .1), neoadjuvant therapy (P = .00 < .1), American Society of Anesthesiologists (ASA) score of ≥3 (P = .00 < .1), anastomotic leakage (P = .01 < .1), local recurrence (P = .00 < .1), and distant recurrence (P = .00 < .1) were associated with the patient with PS. However, sex (P = .15 > .1), previous abdominal surgery (P = .84 > .1), adjuvant chemotherapy (P = .87 > .1), and defunctioning stoma (P = .1) had little association with PS. Conclusion: Patients who were elderly, had advanced tumor stages, had a high ASA score, and underwent neoadjuvant therapy should be informed of the high risk of PS before surgery. Meanwhile, those who underwent rectal cancer surgery with a TS should beware of anastomotic leakage, local recurrences, and distant recurrences, which could increase the risk of PS.

A prospective cohort study on active surveillance after neoadjuvant chemoradiotherapy for esophageal cancer: protocol of Surgery As Needed for Oesophageal cancer-2

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) followed by esophagectomy is a standard treatment for potentially curable esophageal cancer. Active surveillance in patients with a clinically complete response (cCR) 12 weeks after nCRT is regarded as possible alternative to standard surgery. The aim of this study is to monitor the safety, adherence and effectiveness of active surveillance in patients outside a randomized trial.

METHODS

This nationwide prospective cohort study aims to accrue operable patients with non-metastatic histologically proven adenocarcinoma or squamous cell carcinoma of the esophagus or esophagogastric junction. Patients receive nCRT and response evaluation consists of upper endoscopy with bite-on-bite biopsies, endoscopic ultrasonography plus fine-needle aspiration of suspicious lymph nodes and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography scan. When residue or regrowth of tumor in the absence of distant metastases is detected, surgical resection is advised. Patients with cCR after nCRT are suitable to undergo active surveillance. Patients can consult an independent physician or psychologist to support decision-making. Primary endpoint is the number and severity of adverse events in patients with cCR undergoing active surveillance, defined as complications from response evaluations, delayed surgery and the development of distant metastases. Secondary endpoints include timing and quality of diagnostic modalities, overall survival, progression-free survival, fear of cancer recurrence and decisional regret.

DISCUSSION

Active surveillance after nCRT may be an alternative to standard surgery in patients with esophageal cancer. Similar to organ-sparing approaches applied in other cancer types, the safety and efficacy of active surveillance needs monitoring before data from randomized trials are available.

TRIAL REGISTRATION

The SANO-2 study has been registered at ClinicalTrials.gov as NCT04886635 (May 14, 2021) - Retrospectively registered.

The impact of the anastomotic configuration on low anterior resection syndrome 3 years after total mesorectal excision for rectal cancer: a national cohort study

AIM

After low anterior resection, the bowel can be anastomosed in different ways. It is not clear which configuration is optimal from a functional and complication point of view. The primary aim was to investigate the impact of the anastomotic configuration on bowel function evaluated by the low anterior resection syndrome (LARS) score. Secondarily, the impact on postoperative complications was evaluated.

METHOD

All patients who had undergone low anterior resection from 2015 to 2017 were identified in the Swedish Colorectal Cancer Registry. Three years after surgery, patients were sent an extensive questionnaire and were analysed based on anastomotic configuration ('J-pouch/side-to-end anastomosis' or 'straight anastomosis'). Inverse probability weighting by propensity score was used to adjust for confounding factors.

RESULTS

Among 892 patients, 574 (64%) responded, of whom 494 patients were analysed. After weighting, the anastomotic configuration had no significant impact on the LARS score (J-pouch/side-to-end OR 1.05, 95% confidence interval [CI] 0.82-1.34). The J-pouch/side-to-end anastomosis was significantly associated with overall postoperative complications (OR 1.43, 95% CI 1.06-1.95). No significant difference was seen regarding surgical complications (OR 1.14, 95% CI 0.78-1.66).

CONCLUSION

This is the first study investigating the impact of the anastomotic configuration on long-term bowel function, evaluated by the LARS score, in an unselected national cohort. Our results suggested no benefit for J-pouch/side-to-end anastomosis on long-term bowel function and postoperative complication rates. The anastomotic strategy may be based upon the anatomical conditions of the patient and surgical preference.

A novel nomogram to predict low anterior resection syndrome (LARS) after ileostomy reversal for rectal cancer patients

BACKGROUND AND AIM

Low anterior resection syndrome (LARS) in patients undergoing low or ultra-low anterior resection (LAR) is a common problem and significantly impacts the quality of life. Patients with an ileostomy after LAR are more likely to develop LARS. However, there hasn't been a model predicting LARS occurrence in these patients. This study aims to construct a nomogram to predict the probability of LARS occurrence in patients with temporary ileostomy and guide preventive strategies before reversal.

METHODS

168 patients undergoing LAR with ileostomy from one center were enrolled as the training cohort, and 134 patients of the same inclusion criteria from another center were enrolled as the validation cohort. The training cohort was screened for risk factors for major LARS using univariate and multivariate logistic regression. The nomogram was constructed using the filtered variables, the ROC curve was used to describe the model's discrimination, and the calibration was used to describe the accuracy.

RESULTS

The optimal cut-off value for stoma closure time was 128 days. Three risk factors were identified using logistic regression analysis: preoperative radiotherapy (OR = 3.038, [95%CI 1.75-5.015], P = 0.005), stoma closure time (OR = 2.298, [95%CI 1.088-4.858], P = 0.029) and pN stage (OR = 1.739, [95%CI 1.235-3.980], P = 0.001). A nomogram was constructed based on these three variables and showed good performance predicting major LARS after stoma reversal. The area under the curve (AUC) was 0.827 in the training group and 0.821 in the validation group; The calibration curve suggested good precision in both groups.

CONCLUSIONS

This novel nomogram can accurately predict the probability of major LARS occurrence after ileostomy reversal for rectal cancer patients. This model can help screen ileostomy patients with high risks and guide individualized preventive strategies before stoma reversal.

Permanent stoma after sphincter preservation for rectal cancer. A situation that occurs more often than you might think

Objectives

This study aimed: (i) to assess the cumulative incidence of permanent stoma (PS) after sphincter-preserving surgery (SPS) for rectal cancer (RC): (ii) to analyze associated risk factors for primary and secondary PS; and (iii) to compare the long-term survival of patients according to the stoma state.

Methods

We conducted a retrospective single-center cohort study based on a prospectively maintained database of SRC patients undergoing SPS from January 2007 to December 2017. Incidence of both primary (no reversal of defunctioning stoma) and secondary (created after closure of defunctioning stoma) PS were investigated. Associations between potential risk factors and PS were analyzed using a logistic regression model. Cumulative survival curve was drawn by Kaplan-Meier method.

Results

Of the 257 eligible patients, 43 patients (16.7%) had a PS (16 primary PS and 27 secondary PS) after a median follow-up of 4.8 years. In multivariate analysis, the independent risk factors for primary PS were severe post-operative complications (OR 3.66; 95% CI, 1.19-11.20, p=0.022), and old age (OR 1.11; 95% CI 1.04-1.18, p=0.001) and those for secondary PS were local recurrence (OR 38.07; 95% CI 11.07-130.9, p<0.0001), anastomotic leakage (OR 7.01; 95% CI, 2.23-22.04, p=0.009), and severe post-operative complications (OR 3.67; 95% CI, 1.22-11.04, p=0.02), respectively. Both overall survival (OS) and disease-free survival (DFS) were significantly lower in patients with a PS compared with patients with SPS (p < 0.01).

Conclusions

This present study suggests that one out of 6 patients has a PS, 5 years after rectal resection with SPS for SRC.

Can physiological stimulation prior to ileostomy closure reduce postoperative ileus? A prospective multicenter pilot study

BACKGROUND

The aim of this study was to assess the impact of ileostomy closure following preoperative physiological stimulation (PPS) on postoperative ileus (POI) in patients with loop ileostomy after low anterior resection for rectal cancer.

METHODS

Patients who underwent ileostomy closure between January 2017 and February 2020 in two tertiary referral centers were prospectively included. PPS stimulation was compared to standard treatment. Stimulation was carried out daily during the 15 days prior to ileostomy closure by the patient's self-instillation of 200 ml of fecal contents from the ileostomy bag via the efferent loop, using a rectal catheter. Standard treatment (ST) consisted of observation. Outcomes measures were POI, morbidity, stimulation feasibility, and predictors to ileus.

RESULTS

A total of 58 patients were included [42 males and 16 females, median age 67 (43-85) years]. PPS was used in 24 patients, who completed the entire stimulation process, and ST in 34 patients. No differences in preoperative factors were found between the two groups. POI was significantly lower in the PPS group (4.2%) vs the ST group (32.4%); p < 0.01, OR: 0.05 (CI 95% 0.01-0.65). The PPS group had a shorter time to restoration of bowel function (1 day vs 3 days) p = 0.02 and a shorter time to tolerance of liquids (1 day vs 2 days), p = 0.04. Age (p = 0.01), open approach at index surgery, p = 0.03, adjuvant capecitabine (p = 0.01). and previous abdominal surgeries (p = 0.02) were associated with POI in the multivariate analysis. C-reactive-protein values on the 3rd (p = 0.02) and 5th (p < 0.01) postoperative day were also associated with POI.

CONCLUSIONS

PPS for patients who underwent ileostomy closure after low anterior resection for rectal cancer is feasible and might reduce POI.

Anastomotic leakage following restorative rectal cancer resection: treatment and impact on stoma presence 1 year after surgery-a population-based study

PURPOSE

Anastomotic leakage (AL) continues to be a challenge after restorative rectal resection (RRR). Various treatment options of AL are available; however, their long-term outcomes are uncertain. We explored the impact of AL on the risk of stoma presence 1 year after RRR for rectal cancer and described treatment of AL after RRR including impact on the probability of receiving adjuvant chemotherapy and stoma presence following different treatment options of AL.

METHODS

We included 859 patients undergoing RRR in Central Denmark Region between 2013 and 2019. Stoma presence was calculated as the proportion of patients with stoma 1 year after RRR. Multivariable logistic regression was conducted to estimate the impact of AL on stoma presence adjusting for potential predictors. Descriptive data of outcomes were stratified for various treatment options of AL.

RESULTS

The risk of stoma presence 1 year after surgery was 9.8% (95% CI 7.98-12.0). Predictors for having stoma 1 year after RRR were AL (OR 8.43 (95% CI 4.87-14.59)) and low tumour height (OR 3.85 (95% CI 1.22-13.21)). For patients eligible for adjuvant chemotherapy, the probability of receiving it was 42.9% (95% CI 21.8-66.0) if treated with endo-SPONGE and 71.4% (95% CI 47.8-88.7) if treated with other anastomosis preserving treatment options. The risk of having stoma 1 year after RRR was 33.9% (95% CI 21.8-47.8) for patients treated with endo-SPONGE and 13.5% (95% CI 5.6-25.8) for patients treated with other anastomosis preserving treatment options (p = 0.013).

CONCLUSION

AL is a strong predictor for stoma presence 1 year after RRR. Patients treated with endo-SPONGE seem to have worse outcomes compared to other anastomosis preserving treatment options.

Permanent stoma rates after anterior resection for rectal cancer: risk prediction scoring using preoperative variables

BACKGROUND

A permanent stoma after anterior resection for rectal cancer is common. Preoperative counselling could be improved by providing individualized accurate prediction modelling.

METHODS

Patients who underwent anterior resection between 2007 and 2015 were identified from the Swedish Colorectal Cancer Registry. National Patient Registry data were added to determine presence of a stoma 2 years after surgery. A training set based on the years 2007-2013 was employed in an ensemble of prediction models. Judged by the area under the receiving operating characteristic curve (AUROC), data from the years 2014-2015 were used to evaluate the predictive ability of all models. The best performing model was subsequently implemented in typical clinical scenarios and in an online calculator to predict the permanent stoma risk.

RESULTS

Patients in the training set (n = 3512) and the test set (n = 1136) had similar permanent stoma rates (13.6 and 15.2 per cent). The logistic regression model with a forward/backward procedure was the most parsimonious among several similarly performing models (AUROC 0.67, 95 per cent c.i. 0.63 to 0.72). Key predictors included co-morbidity, local tumour category, presence of metastasis, neoadjuvant therapy, defunctioning stoma use, tumour height, and hospital volume; the interaction between age and metastasis was also predictive.

CONCLUSION

Using routinely available preoperative data, the stoma outcome at 2 years after anterior resection for rectal cancer can be predicted fairly accurately.

Safety and efficacy of side-to-end anastomosis versus colonic J-pouch anastomosis in sphincter-preserving resections: an updated meta-analysis of randomized controlled trials

Background

The application of side-to-end anastomosis (SEA) in sphincter-preserving resection (SPR) is controversial. We performed a meta-analysis to compare the safety and efficacy of SEA with colonic J-pouch (CJP) anastomosis, which had been proven effective in improving postoperative bowel function.

Methods

The protocol was registered in PROSPERO under number CRD42020206764. PubMed, Embase, Web of Science, and the Cochrane Register of Controlled Trials databases were searched. The inclusion criteria were randomized controlled trials (RCTs) that evaluated the safety or efficacy of SEA in comparison with CJP anastomosis. The outcomes included the pooled risk ratio (RR) for dichotomous variables and weighted mean differences (WMDs) for continuous variables. All outcomes were calculated with 95% confidence intervals (CI) by STATA software (Stata 14, Stata Corporation, TX, USA).

Results

A total of 864 patients from 10 RCTs were included in the meta-analysis. Patients undergoing SEA had a higher defecation frequency at 12 months after SPR (WMD = 0.20; 95% CI, 0.14–0.26; P < 0.01) than those undergoing CJP anastomosis with low heterogeneity (I² = 0%, P = 0.54) and a lower incidence of incomplete defecation at 3 months after surgery (RR = 0.28; 95% CI, 0.09–0.86; P = 0.03). A shorter operating time (WMD = − 17.65; 95% CI, − 23.28 to − 12.02; P < 0.01) was also observed in the SEA group without significant heterogeneity (I² = 0%, P = 0.54). A higher anorectal resting pressure (WMD = 6.25; 95% CI, 0.17–12.32; P = 0.04) was found in the SEA group but the heterogeneity was high (I² = 84.5%, P = 0.84). No significant differences were observed between the groups in terms of efficacy outcomes including defecation frequency, the incidence of urgency, incomplete defecation, the use of pads, enema, medications, anorectal squeeze pressure and maximum rectal volume, or safety outcomes including operating time, blood loss, the use of protective stoma, postoperative complications, clinical outcomes, and oncological outcomes.

Conclusions

The present evidence suggests that SEA is an effective anastomotic strategy to achieve similar postoperative bowel function without increasing the risk of complications compared with CJP anastomosis. The advantages of SEA include a shorter operating time, a lower incidence of incomplete defecation at 3 months after surgery, and better sphincter function. However, close attention should be paid to the long-term defecation frequency after SPR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02243-0.

Development of a Risk Scoring System for Predicting Anastomotic Leakage Following Laparoscopic Rectal Cancer Surgery

Purpose

To develop a risk scoring system that can predict the incidence of anastomotic leakage after laparoscopic rectal cancer surgery.

Patients and Methods

The clinical data of 387 patients with rectal cancer who underwent laparoscopic low anterior resection were retrospectively collected. Univariable and multivariable logistic regression analyses were used to evaluate independent risk factors for postoperative anastomotic leakage. A simplified points system was then developed based on the corresponding regression coefficient β of each risk factor. Receiver operating characteristic (ROC) analysis was used to evaluate the performance and the optimal cut-off value in predicting anastomotic leakage. The performance of the points system was then externally validated in an independent cohort of 192 patients based in another institution.

Results

Anastomotic leakage occurred in 36 of 387 patients with rectal cancer (9.30%). Logistic multivariable regression analysis showed that males, maximum tumor diameter (≥5cm), operation time (≥180min), preoperative chemoradiation, intraoperative blood transfusion and the anastomosis level from the anal verge (≤5cm) were independent risk factors for the incidence of anastomotic leakage. According to the scoring standard, the risk points of each patient were calculated. ROC analysis based on the risk points showed that the area under the curve (AUC) was 0.795 (95% CI:0.752-0.834) and the optimal cut-off value was 6, yielding a sensitivity of 88.89% and a specificity of 62.96%. Using this risk points system, the AUC of another cohort of 192 patients from another institution who underwent laparoscopic low anterior resection for rectal cancer was 0.853 (95% CI:0.794-0.900, p<0.001) and patients with risk points ≥6 had a 21.05% chance of developing anastomotic leakage.

Conclusion

This risk points system for predicting anastomotic leakage following laparoscopic rectal cancer surgery may be useful for surgeons in their decisions to perform intraoperative diversion stoma, which can reduce the incidence of postoperative anastomotic leakage.