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Background: Anastomotic leakage is a serious complication following anterior resection for rectal cancer and may increase the risk of long-term bowel dysfunction. This study aimed to assess the long-term impact of anastomotic leakage on major low anterior resection syndrome (major LARS) at a uniform follow-up time.

Methods: We conducted a nationwide cohort study using the Swedish Colorectal Cancer Registry. Patients who underwent anterior resection for rectal cancer between 2015 and 2017 received the validated LARS questionnaire by mail 3 years after surgery. The primary outcome was major LARS among patients without a permanent stoma. Propensity score weighting was used to adjust for confounding, with covariates chosen using a directed acyclic graph. Sensitivity analyses included a dose–response analysis based on reoperation and an evaluation of a composite outcome of major LARS or permanent stoma.

Results: Of 1778 patients contacted, 1178 responded (66.2%). Among 1033 stoma-free patients, 52 (5.0%) had experienced a symptomatic anastomotic leak. Major LARS was reported in 69.2% and 52.9% of patients with and without leakage, respectively. Symptomatic anastomotic leakage increased the risk of major LARS (OR 2.09; 95% CI: 1.13–3.87) and this risk was higher in patients requiring reintervention (OR 2.78; 95% CI: 0.87–8.91) and when including permanent stoma in the outcome (OR 3.90; 95% CI: 2.20–6.91).

Conclusion: Anastomotic leakage significantly increased the risk of major LARS 3 years after anterior resection for rectal cancer. These findings underscore the importance of preventing anastomotic leakage to reduce long-term functional morbidity in patients who survive rectal cancer.

Objectives: FDG PET/MRI is a promising imaging modality for nodal staging in rectal cancer; however, its role remains to be defined. We aimed to assess its performance in detecting mesorectal malignant lymph node involvement based on both metabolic and morphological criteria at PET/MRI versus at MRI alone.

Materials & methods: Sixty-five patients (median age 70 years, IQR 61–74; 39 men) were examined with FDG PET/MRI followed by individual anatomical matching of mesorectal nodal structures between histopathology and MRI. PET N-stage assessment was evaluated using FDG uptake over background levels, MRI N-stage by the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus criteria and PET/MRI was evaluated using both in combination. Histopathological assessment served as gold standard, and the accuracy of identifying malignancy at both nodal and patient level was calculated. Furthermore, FDG PET/MRI and MRI using ESGAR criteria for nodal restaging after neoadjuvant treatment were also evaluated.

Results: In total, 835 nodal structures were matched, of which 104 were malignant (12%); among these, 59/104 (57%) were histopathologically proven lymph node metastases. MRI alone yielded a sensitivity of 54% and specificity of 85% for nodal malignancy, while the corresponding estimates for FDG-avidity gave a 75% sensitivity and 79% specificity. The different combined FDG PET/MRI criteria for malignancy were evaluated: FDG-positivity or malignancy according to ESGAR criteria resulted in a sensitivity of 76%; while the combination of FDG-positivity and malignancy according to ESGAR criteria achieved a specificity of 90%.

Conclusion: Compared to MRI alone, FDG PET/MRI offers potential added value by reducing the risk of nodal understaging.

Aim: Palliative rectal cancer patients typically retain their primary tumour, as trials have concluded no survival benefit of tumour resection in non-curative patients. This patient group is understudied regarding the natural course of the remaining tumour, particularly concerning the need of surgical management.

Method: This was a retrospective study on rectal cancer patients diagnosed between 2007 and 2020 in Region Västerbotten, Sweden. Data were obtained from the Swedish Colorectal Cancer Registry and chart review. Patients were excluded if treated with curative intent, underwent primary tumour resection, had a synchronous colorectal cancer, had locally recurrent colorectal cancer, or refused treatment. Patients were followed from diagnosis until death or end of follow-up. Indications for palliative treatment, tumour-related complications and surgical and oncological management were investigated, with a stratified analysis for study period and patient age.

Results: Some 156 patients remained after applying exclusion criteria. The majority had metastasized and incurable disease (76%). Almost half suffered local complications (44%) and 48% underwent surgical intervention, due to the unremoved primary tumour. Tumour perforation occurred in 7% with a significantly higher risk in patients aged ≤75 years (p = 0.009). Bowel obstruction afflicted 23%, while 40% underwent stoma diversion. Almost half received chemotherapy (48%) and radiotherapy (42%), respectively.

Conclusion: Rectal cancer patients with an unremoved primary tumour face a substantial risk of local complications, often necessitating surgical intervention. Therefore, the benefits of surgical resection should be carefully considered, especially for patients with a longer estimated survival. Further research is needed to accurately identify patients where tumour removal might be beneficial.

A colorectal-vaginal fistula (CRVF) can occur as a complication of rectal cancer surgery. They can cause discomfort, repeated infection, need for treatment/further surgery, and a permanent stoma (an opening in the abdomen to collect bowel contents). This study looked at how often CRVF happened after surgery complicated by a leak where bowels ends have been joined together, how they were treated, and how likely patients were to live without a stoma 1 year after surgery. Researchers collected data on women from around the world who had rectal cancer surgery between 2014 and 2018 and developed a bowel leak (called anastomotic leakage). They compared those with and without a CRVF. A total of 88 out of 694 patients (12.7%) developed a CRVF. These patients more often had major surgery involving removal of nearby organs, including part of the vagina. They were more likely to have ongoing problems and needed more surgeries to manage them. Most had a temporary stoma, but only 29.5% could live without it after 1 year, compared with 48.7% of women without CRVF. CRVF is a serious complication that makes recovery harder. These patients are less likely to live without a stoma and usually need more surgery. However, if the leak is small, the chances of recovery without a permanent stoma are better.

Aim: The selective use of defunctioning stomas in anterior resection for rectal cancer hinges on accurately predicting anastomotic leakage. The aim of this study was to develop a prediction model for use in a prospective randomized clinical trial.

Method: Colorectal Cancer Database (CRCBaSe) Sweden was used to identify patients who underwent low anterior resection for rectal cancer 2007–2021. Eligibility criteria mirrored the forthcoming SELective defunctioning Stoma Approach in low anterior resection for rectal cancer (SELSA) trial, including patients <80 years of age and with American Society of Anaesthesiologists' (ASA) physical status grade of <III; further, patients without a defunctioning stoma were excluded. The outcome comprised anastomotic leakage within 30 days or in-hospital. Candidate predictors included age, sex, ASA grade, cardiovascular disease, diabetes, body mass index (BMI), tumour stage, tumour height, and neoadjuvant therapy. Seven models were developed and internally validated using bootstrapping. A threshold of a predicted leakage risk of ≤10% was chosen for trial implementation. Validation was conducted using chart-reviewed data from a nested cohort.

Results: Of the 2727 eligible patients, 199 (7.3%) were registered with an anastomotic leakage. All models demonstrated similar performance, with prediction instability observed for risks exceeding 12.5%. The preferred model included three significant predictors: male sex (OR 2.00; 95% CI: 1.45–2.75), BMI >30 kg/m2 (OR 1.82; 95% CI: 1.21–2.74), and radiotherapy (OR 1.90; 95% CI: 1.35–2.69). The bootstrapped area under the curve (AUC) was 0.64 (95% CI: 0.62–0.65), with a negative predictive value of 94.6% (95% CI: 93.7%–95.6%). For the validation cohort, the corresponding estimates were 0.66 (95% CI: 0.59–0.74) and 89.5% (95% CI: 86.2%–92.5%).

Conclusion: Accuracy of anastomotic leakage prediction using registry-based data is moderate; however, the model's ability to rule out a >10% risk is considered appropriate for trial use.

Background: Postoperative death measured 30 days after surgery is a conventional quality metric, whereas intervals up to 90 days are increasingly used, although data-driven time windows have scarcely been investigated.

Methods: The Swedish Colorectal Cancer Registry was used to identify all patients subjected resection for colorectal cancer between 2007 and 2020. All patients were followed up until 180 days after surgery. A join-point statistical hazard model was used to model a declining hazard to a transition point, followed by a stable death rate. This method was subsequently applied to describe postoperative deaths for the entire cohort and subgroups according to tumour location (colon and rectum).

Results: Some 56 096 patients electively operated on for colorectal cancer during the study interval were included, with a 30-day and 90-day fatality of 805 (1.43%) and 1458 (2.60%) patients respectively. The derived postoperative fatality window, after which the death rate transitioned to a stable rate, was 23.8 (95% c.i. 21.5 to 28.2) days after surgery. There was no significant difference in the time window between rectal cancer (22.9 days; 95% c.i. 15.1 to 28.4) and colon cancer (27.3 days; 95% c.i. 21.4 to 31.8) patients (P = 0.455). However, postoperative fatality time windows were extended in patients aged at least 80 years and with American Society of Anesthesiologists’ grade III or IV.

Conclusion: The traditional postoperative time window of 30 days was confirmed to be an appropriate metric in elective colorectal cancer surgery when evaluated with a hazards-based statistical framework. Importantly, this time window is influenced by older age and advanced co-morbidity, which could prompt increased vigilance for these patient groups.

Purpose: To evaluate current MRI-based criteria for malignancy in mesorectal nodal structures in rectal cancer.

Method: Mesorectal nodal structures identified on baseline MRI as lymph nodes were anatomically compared to their corresponding structures histopathologically, reported as lymph nodes, tumour deposits or extramural venous invasion. All anatomically matched nodal structures from patients with primary surgery and all malignant nodal structures from patients with neoadjuvant treatment were included. Mixed-effects logistic regression models were used to evaluate the morphological criteria irregular margin, round shape, heterogeneous signal and nodal size, as well as the combined 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus criteria, with histopathological nodal status as the gold standard.

Results: In total, 458 matched nodal structures were included from 46 patients (mean age, 67.7 years ± 1.5 [SD], 27 men), of which 19 received neoadjuvant treatment. The strongest associations in the univariable model were found for short-axis diameter ≥ 5 mm (OR 21.43; 95% CI: 4.13–111.29, p < 0.001) and heterogeneous signal (OR 9.02; 95% CI: 1.33–61.08, p = 0.024). Only size remained significant in multivariable analysis (OR 12.32; 95% CI: 2.03–74.57, p = 0.006). When applying the ESGAR consensus criteria to create a binary classification of nodal status, the OR of malignant outcome for nodes with positive ESGAR was 8.23 (95% CI: 2.15–31.50, p = 0.002), with corresponding sensitivity and specificity of 54% and 85%, respectively.

Conclusion: The results confirm the role of morphological and size criteria in predicting lymph node metastases. However, the current criteria might not be accurate enough for nodal staging.

Aim: The risk of anastomotic leakage after colorectal cancer surgery is higher in men, regardless of the anatomical location. Previous studies suggest that this might be due to hormonal differences. The aim of this work was to investigate whether androgen deprivation therapy influenced the incidence of anastomotic leakage.

Method: This is a nationwide registry-based study of men operated on between 2007 and 2021 for colorectal cancer with an anastomosis. Exposure to androgen deprivation therapy (prescribed drugs or surgical castration) was related to anastomotic leakage using mixed-effects logistic regression models. Two control groups were formed: one without and one with prostate cancer but without androgen deprivation. To study the potential target for androgen effect in intestinal tissue, androgen receptor expression was evaluated using immunohistochemistry in a smaller independent cohort to compare receptor expression in relation to leakage.

Results: Some 24 611 men were included in the registry study, of whom 2.4% were exposed to androgen deprivation therapy. In this exposed group, compared with unexposed men with and without prostate cancer, respectively, leak rates were 3.7%, 5.6% and 5.8%, respectively. After adjustment, a nonsignificant reduction of anastomotic leakage in the exposed group was detected (OR 0.70, 95% CI 0.45–1.09) compared with men without prostate cancer. Tissue expression of androgen receptor was very low among patients with and without leakage, albeit with a trend of higher expression among the latter.

Conclusion: Anastomotic leakage rates might be lower in men exposed to androgen deprivation therapy before surgery for colorectal cancer, although this finding must be interpreted cautiously. Effects on anastomotic healing do not seem to be mediated through classical androgen receptor signalling in the intestine.

PURPOSE: Defunctioning stoma (DS) has been suggested to mitigate the consequences of anastomotic leak (AL) after low anterior resection. Stoma reversal (SR) is commonly delayed for nonmedical reasons in many healthcare systems. This study investigated the impact of the elapsed time from AR to SR on postoperative 90-day complications. The secondary aim was to explore the independent factors associated with a delayed SR.

M&M: This multicenter retrospective cohort study included rectal cancer patients who underwent anterior resection (AR) and DS between 2014 and 2018. Multivariable logistic regression was used to evaluate the influence of the elapsed time from AR to SR on postoperative complications within 90 days.

RESULTS: Out of 905 patients subjected to AR with DS, 116 (18%) patients experienced at least one postoperative 90-day complication after SR. Multivariable analysis revealed an association between the elapsed time to SR and complications within 90 days from SR (OR 1.02; 95% CI, 1.00-1.04). The association with SR complications was further highlighted in patients who experienced delayed SR > 6 months after AR (OR 1.73; 95% CI, 1.04-2.86). AL after AR and nodal disease were both related to delayed SR.

CONCLUSION: This study demonstrated that postoperative 90-day complications are associated with the time elapsed to SR. These findings emphasize the importance of early SR, preferably within 6 months, to prevent complications.