Factors affecting sphincter-preserving resection treatment for patients with low rectal cancer

Unraveling variations and enhancing prediction of successful sphincter-preserving resection for low rectal cancer: a post hoc analysis of the multicentre LASRE randomized clinical trial

BACKGROUND

Accurate prediction of successful sphincter-preserving resection (SSPR) for low rectal cancer enables peer institutions to scrutinize their own performance and potentially avoid unnecessary permanent colostomy. The aim of this study is to evaluate the variation in SSPR and present the first artificial intelligence (AI) models to predict SSPR in low rectal cancer patients.

STUDY DESIGN

This was a retrospective post hoc analysis of a multicenter, non-inferiority randomized clinical trial (LASRE, NCT01899547) conducted in 22 tertiary hospitals across China. A total of 604 patients who underwent neoadjuvant chemoradiotherapy (CRT) followed by radical resection of low rectal cancer were included as the study cohort, which was then split into a training set (67%) and a testing set (33%). The primary end point of this post hoc analysis was SSPR, which was defined as meeting all the following criteria: (1) sphincter-preserving resection; (2) complete or nearly complete TME, (3) a clear CRM (distance between margin and tumour of 1 mm or more), and (4) a clear DRM (distance between margin and tumour of 1 mm or more). Seven AI algorithms, namely, support vector machine (SVM), logistic regression (LR), extreme gradient boosting (XGB), light gradient boosting (LGB), decision tree classifier (DTC), random forest (RF) classifier, and multilayer perceptron (MLP), were employed to construct predictive models for SSPR. Evaluation of accuracy in the independent testing set included measures of discrimination, calibration, and clinical applicability.

RESULTS

The SSPR rate for the entire cohort was 71.9% (434/604 patients). Significant variation in the rate of SSPR, ranging from 37.7 to 94.4%, was observed among the hospitals. The optimal set of selected features included tumour distance from the anal verge before and after CRT, the occurrence of clinical T downstaging, post-CRT weight and clinical N stage measured by magnetic resonance imaging. The seven different AI algorithms were developed and applied to the independent testing set. The LR, LGB, MLP and XGB models showed excellent discrimination with area under the receiver operating characteristic (AUROC) values of 0.825, 0.819, 0.819 and 0.805, respectively. The DTC, RF and SVM models had acceptable discrimination with AUROC values of 0.797, 0.766 and 0.744, respectively. LR and LGB showed the best discrimination, and all seven AI models had superior overall net benefits within the range of 0.3-0.8 threshold probabilities. Finally, we developed an online calculator based on the LGB model to facilitate clinical use.

CONCLUSIONS

The rate of SSPR exhibits substantial variation, and the application of AI models has demonstrated the ability to predict SSPR for low rectal cancers with commendable accuracy.

Can Pre-Treatment Inflammatory Parameters Predict the Probability of Sphincter-Preserving Surgery in Patients with Locally Advanced Low-Lying Rectal Cancer?

There is evidence suggesting that pre-treatment clinical parameters can predict the probability of sphincter-preserving surgery in rectal cancer; however, to date, data on the predictive role of inflammatory parameters on the sphincter-preservation rate are not available. The aim of the present cohort study was to investigate the association between inflammation-based parameters and the sphincter-preserving surgery rate in patients with low-lying locally advanced rectal cancer (LARC). A total of 848 patients with LARC undergoing radiotherapy from 2004 to 2019 were retrospectively reviewed in order to identify patients with rectal cancer localized ≤6 cm from the anal verge, treated with neo-adjuvant radiochemotherapy (nRCT) and subsequent surgery. Univariable and multivariable analyses were used to investigate the role of pre-treatment inflammatory parameters, including the C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) for the prediction of sphincter preservation. A total of 363 patients met the inclusion criteria; among them, 210 patients (57.9%) underwent sphincter-preserving surgery, and in 153 patients (42.1%), an abdominoperineal rectum resection was performed. Univariable analysis showed a significant association of the pre-treatment CRP value (OR = 2.548, 95% CI: 1.584–4.097, p < 0.001) with sphincter preservation, whereas the pre-treatment NLR (OR = 1.098, 95% CI: 0.976–1.235, p = 0.120) and PLR (OR = 1.002, 95% CI: 1.000–1.005, p = 0.062) were not significantly associated with the type of surgery. In multivariable analysis, the pre-treatment CRP value (OR = 2.544; 95% CI: 1.314–4.926; p = 0.006) was identified as an independent predictive factor for sphincter-preserving surgery. The findings of the present study suggest that the pre-treatment CRP value represents an independent parameter predicting the probability of sphincter-preserving surgery in patients with low-lying LARC.

The Outcome of Induction Chemotherapy, Followed by Neoadjuvant Chemoradiotherapy and Surgery, in Locally Advanced Rectal Cancer

Background & Objective

Currently, neoadjuvant chemoradiotherapy, followed by surgery, is the standard treatment for locally advanced rectal cancer. The use of induction chemotherapy for this tumor is controversial. In this study, the benefits and side effects of induction chemotherapy in locally advanced rectal cancer are evaluated.

Methods

Twenty-nine patients with locally advanced rectal cancer in 2018-2019 were enrolled in this study. Initially, they underwent induction chemotherapy (oxaliplatin 130 mg/m² every 3 weeks and capecitabine 1000 mg/m² twice a day for 14 days every 3 weeks for 2 courses). Then, neoadjuvant chemoradiotherapy (radiotherapy 50.4 Gy/28 for 5 days a week concomitant with weekly oxaliplatin 50 mg/m², as well as capecitabine 825 mg/m²/bid on the days of radiotherapy) was administered. After 4 weeks, computed tomography (CT) scan of thorax, pelvis, and abdomen with and without contrast was performed. Total mesorectal surgery was performed 6-8 weeks after the end of radiotherapy. Four courses of adjuvant chemotherapy were applied. Pathologic complete response (pCR), margin, sphincter preservation, and adverse effects were assessed.

Results

In this study, pCR was present in 6 (20.7%) patients. R0 resection was done in 96.05%. Sphincter was preserved in 44.4% of lower rectal tumors. Two patients (6.9%) did not complete adjuvant treatment. Grade 3 adverse effects were documented in 13.7% of cases during induction chemotherapy and 17.2% of cases during neoadjuvant chemoradiation. Mortality was not reported.

Conclusion

Induction chemotherapy, followed by neoadjuvant chemoradiotherapy and surgery, would be an effective and safe modality in locally advanced rectal cancer.

Diabetes mellitus and colorectal carcinoma outcomes: a meta-analysis

OBJECTIVES

The impact of diabetes mellitus (DM) on colorectal cancer (CRC) outcomes remains unknown. We studied this by conducting a meta-analysis to evaluate (1) CRC outcomes with and without DM and (2) treatment patterns.

METHODS

We searched PubMed, EMBASE, Google Scholar, and CINAHL for full-text English studies from 1970 to 12/31/2017. We searched keywords, subject headings, and MESH terms to locate studies of CRC outcomes/treatment and DM. Studies were evaluated by two oncologists. Of 14,332, 48 met inclusion criteria. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, we extracted study location, design, DM definition, covariates, comparison groups, outcomes, and relative risks and/or hazard ratios. We utilized a random-effects model to pool adjusted risk estimates. Primary outcomes were all-cause mortality (ACM), disease-free survival (DFS), relapse-free survival (RFS), and cancer-specific survival (CSS). The secondary outcome was treatment patterns.

RESULTS

Forty-eight studies were included, 42 in the meta-analysis, and 6 in the descriptive analysis, totaling > 240,000 patients. ACM was 21% worse (OR 1.21, 95% CI 1.15-1.28) and DFS was 75% worse (OR 1.75, 95% CI: 1.33-2.31) in patients with DM. No differences were detected in CSS (OR 1.10, 95% CI 0.98-1.23) or RFS (OR 1.12, 95% CI 0.91-1.38). Descriptive analysis of treatment patterns in CRC and DM suggested potentially less adjuvant therapy use in cases with DM and CRC.

CONCLUSIONS

Our meta-analysis suggests that patients with CRC and DM have worse ACM and DFS than patients without DM, suggesting that non-cancer causes of death in may account for worse outcomes.

Clinical parameters predictive for sphincter-preserving surgery and prognostic outcome in patients with locally advanced low rectal cancer

Background

Although controversial, there are data suggesting that clinical parameters can predict the probability of sphincter preserving procedures in rectal cancer. The purpose of this study was to investigate the association between clinical parameters and the sphincter-preserving surgery rate in patients who had undergone neoadjuvant combination therapy for advanced low rectal cancer.

Methods

In this single center study, the charts of 540 patients with locally advanced rectal cancer who had been treated with induction chemotherapy-and/or neoadjuvant concomitant radiochemotherapy (nRCT) over an 11-year period were reviewed in order to identify patients with rectal cancer ≤6 cm from the anal verge, who had received the prescribed nRCT only. Univariate and multivariate analyses were used to identify pretreatment patient- and tumor associated parameters correlating with sphincter preservation. Survival rates were calculated using Kaplan-Meier analyses.

Results

Two hundred eighty of the 540 patients met the selection criteria. Of the 280 patients included in the study, 158 (56.4%) underwent sphincter-preserving surgery. One hundred sixty-four of 280 patients (58.6%) had a downsizing of the primary tumor (ypT < cT) and 39 (23.8%) of these showed a complete histopathological response (ypT0 ypN0). In univariate analysis, age prior to treatment, Karnofsky performance status, clinical T-size, relative lymphocyte value, CRP value, and interval between nRCT and surgery, were significantly associated with sphincter-preserving surgery. In multivariate analysis, age (hazard ratio (HR) = 1.05, CI95%: 1.02–1.09, p = 0.003), relative lymphocyte value (HR = 0.94, CI95%: 0.89–0.99, p = 0.029), and interval between nRCT and surgery (HR = 2.39, CI95%: 1.17–4.88, p = 0.016) remained as independent predictive parameters.

Conclusions

These clinical parameters can be considered in the prognostication of sphincter-preserving surgery in case of low rectal adenocarcinoma. More future research is required in this area.

Anal function and quality of life analysis after laparoscopic modified Parks for ultra-low rectal cancer patients

Background

To assess postoperative anal function and quality of life of ultra-low rectal cancer patients treated by laparoscopic modified Parks surgery.

Methods

From February 2017 to March 2019, 114 patients with ultra-low rectal cancer above T2 were treated respectively with ultra-low anterior resection (Dixon), modified coloanal anastomosis (modified Parks), and Miles according to the preoperative stage and anastomotic position. The postoperative anal function and Fecal Incontinence Quality of Life Scale (FIQL) of each patient were collected and synthetically analyzed.

Results

Compared with the Dixon group, the postoperative anal function and FIQL in the Parks group were poor at the early stage. However, from 6 to 12 months after surgery, the scores of anal function and FIQL in the Parks group were similar to those in the Dixon group (P > 0.05). Compared with the Miles group, the FIQL of the two groups were similar in the early postoperative stage. However, with the passage of time, from 3 to 9 months after surgery, the four domains of FIQL in the Parks group were higher than those in the Miles group successively (P < 0.05).

Conclusions

Laparoscopic modified Parks is a safe, effective, and economical anus-preserving surgery. Although its early anal function and FIQL were poor, it could gradually recover to the similar level as Dixon. Moreover, it can save the anus and obtain a better postoperative quality of life for some patients who previously could only undergo Miles.