Effects of Neoadjuvant Radiotherapy on Postoperative Complications in Rectal Cancer: A Meta-Analysis

Does surgeon or hospital volume influence outcome in dedicated colorectal units?-A Viennese perspective

OBJECTIVE

A clear relationship between higher surgeon volume and improved outcomes has not been convincingly established in rectal cancer surgery. The aim of this study was to evaluate the impact of individual surgeon's caseload and hospital volume on perioperative outcome.

METHODS

We retrospectively analyzed 336 consecutive patients undergoing oncological resection for rectal cancer at two Viennese hospitals between 1 January 2015 and 31 December 2020. The effect of baseline characteristics as well as surgeons' caseloads (low volume: 0-5 cases per year, high volume > 5 cases per year) on postoperative complication rates (Clavien-Dindo Classification groups of < 3 and ≥ 3) were evaluated.

RESULTS

No differences in baseline characteristics were found between centers in terms of sex, smoking status, or comorbidities of patients. Interestingly, only 14.7% of surgeons met the criteria to be classified as high-volume surgeons, while accounting for 66.3% of all operations. There was a significant difference in outcomes depending on the treating center in univariate and multivariate binary logistic regression analysis (odds ratio (OR) = 2.403, p = 0.008). Open surgery was associated with lower complication rates than minimally invasive approaches in univariate analysis (OR = 0.417, p = 0.003, 95%CI = 0.232-0.739) but not multivariate analysis. This indicated that the center's policy rather than surgeon volume or mode of surgery impact on postoperative outcomes.

CONCLUSION

Treating center standards impacted on outcome, while individual caseload of surgeons or mode of surgery did not independently affect complication rates in this analysis. The majority of rectal cancer resections are performed by a small number of surgeons in Viennese hospitals.

Development and validation of a nomogram to predict the risk factors of major complications after radical rectal cancer surgery

Purpose

The aim of this study was to establish a validated nomogram to predict risk factors for major post-operative complications in patients with rectal cancer (RC) by analyzing the factors contributing to major post-operative complications in RC patients.

Methods

We retrospectively collected baseline and surgical information on patients who underwent RC surgery between December 2012 and December 2022 at a single-center teaching hospital. The entire cohort was randomly divided into two subsets (60% of the data for development, 40% for validation). Independent risk factors for major post-operative complications were identified using multivariate logistic regression analyses, and predictive models were developed. Area under the curve (AUC) was calculated using receiver operating characteristic curve (ROC) to assess predictive probability, calibration curves were plotted to compare the predicted probability of the nomogram with the actual probability, and the clinical efficacy of the nomogram was assessed using decision curve analysis (DCA).

Results

Our study included 3151 patients who underwent radical surgery for RC, including 1892 in the development set and 1259 in the validation set. Forty (2.1%) patients in the development set and 26 (2.1%) patients in the validation set experienced major post-operative complications. Through multivariate logistic regression analysis, age (p<0.01, OR=1.044, 95% CI=1.016-1.074), pre-operative albumin (p<0.01, OR=0.913, 95% CI=0.866-0.964), and open surgery (p<0.01, OR=2.461, 95% CI=1.284-4.761) were identified as independent risk factors for major post-operative complications in RC, and a nomogram prediction model was established. The AUC of the ROC plot for the development set was 0.7161 (95% Cl=0.6397-0.7924), and the AUC of the ROC plot for the validation set was 0.7191 (95% CI=0.6182-0.8199). The predicted probabilities in the calibration curves were highly consistent with the actual probabilities, which indicated that the prediction model had good predictive ability. The DCA also confirmed the good clinical performance of the nomogram.

Conclusion

In this study, a validated nomogram containing three predictors was created to identify risk factors for major complications after radical RC surgery. Due to its accuracy and convenience, it could contribute to personalized management of patients in the perioperative period.

Risk assessment of rectal anastomotic leakage (RAREAL) after DIXON in non-emergency patients with rectal cancer

BACKGROUND

The routine establishment of a diverting stoma (DS) remains controversial in every patient undergoing Dixon operation. We aimed to establish a model for the risk assessment of rectal anastomotic leak (RAREAL) after Dixon in non-emergency patients with rectal cancer, using routinely available variables, by which surgeons could individualize their approach to DS.

METHODS

323 patients who underwent Dixon operation for rectal cancer from January 2015 to December 2018 were taken as the model group for retrospective study. Univariable and multivariable logistic regression analysis was used to determine the independent risk factors associated with anastomotic leakage. We constructed the RAREAL model. 150 patients who underwent Dixon operation due to rectal cancer from January 2019 to December 2020 were collected according to the uniform criteria as a validation group to validate the RAREAL model.

RESULTS

In the model group, multivariable analysis identified the following variables as independent risk factors for AL: HbA1c (odds ratio (OR) = 4.107; P = 0.044), Left colic artery (LCA) non preservation (OR = 4.360; P = 0.026), Tumor distance from the anal margin (TD) (OR = 6.373; P = 0.002). In the model group, the area under the curve (AUC) of the receiver operating characteristic (ROC) for evaluating AL with RAREAL was 0.733, and when RAREAL score = 2.5, its sensitivity, specificity and Youden index were 0.385, 0.973, 0.358, respectively. The AUC was 0.722 in the validation group and its sensitivity and specificity were 0.333 and 0.985, respectively, when RAREAL score = 2.5.

CONCLUSION

The RAREAL score can be used to assess the risk of AL after Dixon operation for rectal cancer, and prophylactic DS should be proactively done when the score is greater than 2.5.

Effect of Glutamine on Short-term Surgical Outcomes in Rectal Cancer Patients Receiving Neoadjuvant Therapy: A Propensity Score Matching Study

The effect of glutamine on postoperative complications and postoperative recovery in rectal cancer (RC) patients receiving neoadjuvant therapy (NT) is unclear. This study aimed to investigate the effects of intravenous glutamine supplementation on short-term postoperative outcomes in these patients. This retrospective study included patients with RC who received NT and underwent radical surgery between January 2013 and July 2022 and were either administered glutamine (glutamine group) or not administered glutamine (non-glutamine group). Propensity score matching method was used to analyze and compare postoperative complications and other outcome indicators. A total of 208 patients were reviewed, and 53 were included in each group post matching. While no significant difference in the time to first solid food intake between the two groups was observed, the glutamine group had a significantly reduced incidence of postoperative complications, shorter length of hospital stay, and shorter time to first defecation, first exhaust, and first fluid diet intake than those of the control group. Moreover, glutamine alleviated the reduction in albumin and prealbumin levels. Perioperative parenteral glutamine supplementation effectively reduces the incidence of postoperative complications, promotes postoperative recovery, and improves albumin levels in patients undergoing RC surgery and receiving NT.

Does temporary ileostomy via specimen extraction site affect the short outcomes and complications after laparoscopic low anterior resection in rectal cancer patients? A propensity score matching analysis

Purpose

The purpose of the current study was to compare the outcomes of temporary stoma through the specimen extraction site (SSES) and stoma through a new site (SNS) after laparoscopic low anterior resection.

Methods

The rectal cancer patients who underwent laparoscopic low anterior resection plus temporary ileostomy were recruited in a single clinical database from Jun 2013 to Jun 2020. The SSES group and the SNS group were compared using propensity score matching (PSM) analysis.

Results

A total of 257 rectal cancer patients were included in this study, there were 162 patients in the SSES group and 95 patients in the SNS group. After 1:1 ratio PSM, there was no difference in baseline information (p > 0.05). The SSES group had smaller intraoperative blood loss (p = 0.016 < 0.05), shorter operation time (p < 0.01) and shorter post-operative hospital stay (p = 0.021 < 0.05) than the SNS group before PSM. However, the SSES group shorter operation time (p = 0.006 < 0.05) than the SNS group after PSM, moreover, there was no significant difference in stoma-related complications (p > 0.05). In the multivariate analysis, longer operation time was an independent factor (p = 0.019 < 0.05, OR = 1.006, 95% CI = 1.001–1.011) for the stoma-related complications.

Conclusion

Based on the current evidence, the SSES group had smaller intraoperative blood loss, shorter operation time and shorter post-operative hospital stay before PSM, and shorter operation time after PSM. Therefore, SSES might be superior than SNS after laparoscopic low anterior resection for rectal cancer patients.

A prognostic nomogram for stage II/III rectal cancer patients treated with neoadjuvant chemoradiotherapy followed by surgical resection

Background

The purpose of this study was to develop a large population-based nomogram incorporating the log odds of positive nodes (LODDS) for predicting the overall survival (OS) of stage II/III rectal cancer patients treated with neoadjuvant chemoradiotherapy (NCRT) followed by surgical resection.

Methods

The Surveillance, Epidemiology, and End Results database was used to collect information on patients diagnosed with stage II/III rectal cancer between 2010 and 2015 and treated with NCRT followed by surgical resection. The Cox regression analyses were performed to determine the independent prognostic factors. In this study, LODDS was employed instead of American Joint Committee on Cancer (AJCC) 7th N stage to determine lymph node status. Then a nomogram integrating independent prognostic factors was developed to predict the 24-, 36-, and 60-month overall survival. The receiver operating characteristic (ROC) curves and calibration curves were used to validate the nomogram. Furthermore, patients were stratified into three risk groups (high-, middle-, and low-risk) based on the total points obtained from the nomogram. And Kaplan–Meier curves were plotted to compare the OS of the three groups.

Results

A total of 3829 patients were included in the study. Race, sex, age, marital status, T stage, tumor grade, tumor size, LODDS, CEA level, and postoperative chemotherapy were identified as independent prognostic factors, based on which the prognostic nomogram was developed. The area under curve values of the nomogram for the 24-, 36-, and 60-month OS in the training cohort were 0.736, 0.720, and 0.688, respectively; and 0.691, 0.696, and 0.694 in the validation cohort, respectively. In both the validation and training cohorts, the calibration curves showed a high degree of consistency between actual and nomogram-predicted survival rates. The Kaplan–Meier curves showed that the three risk groups had significant differences in overall survival (P < 0.001).

Conclusion

A large population-based nomogram incorporating LODDS was developed to assist in evaluating the prognosis of stage II/III rectal cancer patients treated with NCRT followed by surgical resection. The nomogram showed a satisfactorily discriminative and stable ability to predict the OS for those patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01710-z.