Anatomical basis for the choice of laparoscopic surgery for low rectal cancer through the pelvic imaging data-a cohort study

Interpretable machine learning model to predict surgical difficulty in laparoscopic resection for rectal cancer

Background

Laparoscopic total mesorectal excision (LaTME) is standard surgical methods for rectal cancer, and LaTME operation is a challenging procedure. This study is intended to use machine learning to develop and validate prediction models for surgical difficulty of LaTME in patients with rectal cancer and compare these models' performance.

Methods

We retrospectively collected the preoperative clinical and MRI pelvimetry parameter of rectal cancer patients who underwent laparoscopic total mesorectal resection from 2017 to 2022. The difficulty of LaTME was defined according to the scoring criteria reported by Escal. Patients were randomly divided into training group (80%) and test group (20%). We selected independent influencing features using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression method. Adopt synthetic minority oversampling technique (SMOTE) to alleviate the class imbalance problem. Six machine learning model were developed: light gradient boosting machine (LGBM); categorical boosting (CatBoost); extreme gradient boost (XGBoost), logistic regression (LR); random forests (RF); multilayer perceptron (MLP). The area under receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity and F1 score were used to evaluate the performance of the model. The Shapley Additive Explanations (SHAP) analysis provided interpretation for the best machine learning model. Further decision curve analysis (DCA) was used to evaluate the clinical manifestations of the model.

Results

A total of 626 patients were included. LASSO regression analysis shows that tumor height, prognostic nutrition index (PNI), pelvic inlet, pelvic outlet, sacrococcygeal distance, mesorectal fat area and angle 5 (the angle between the apex of the sacral angle and the lower edge of the pubic bone) are the predictor variables of the machine learning model. In addition, the correlation heatmap shows that there is no significant correlation between these seven variables. When predicting the difficulty of LaTME surgery, the XGBoost model performed best among the six machine learning models (AUROC=0.855). Based on the decision curve analysis (DCA) results, the XGBoost model is also superior, and feature importance analysis shows that tumor height is the most important variable among the seven factors.

Conclusions

This study developed an XGBoost model to predict the difficulty of LaTME surgery. This model can help clinicians quickly and accurately predict the difficulty of surgery and adopt individualized surgical methods.

Application of the intestine diversion tube with a double-balloon without ileostomy in low rectal cancer

Background

Ileostomy is often used in low rectal cancer to protect the anastomosis and reduce the incidence of anastomotic leakage. However, the closure of the stoma causes physical and psychological damage to patients. An intestine diversion tube with a double-balloon was designed to remove the need for ileostomy and a secondary surgery, and we sought to verify its effectiveness and safety.

Methods

An intestine diversion tube with a double-balloon was designed, and the experiment was performed in 5 groups of experiment pigs by the same group of physicians. The tube was placed into the ileum through the cecum during surgery. All the animals were anatomized after being anesthetized on the 14th day postoperatively to check the anastomosis and abdominal cavity. The postoperative complications included anastomotic leakage, abdominal or pelvic infection, anastomotic stenosis, postoperative bleeding, intestinal obstruction, reoperation, electrolyte disorder, drainage tube blockage, and drainage tube fall off.

Results

No serious postoperative complications occurred in the 5 animal groups. The average daily drainage tube volume was 188.6 mL, the average drainage tube removal time was 13.4 days, and the average first defecation time was 2.6 days. Postoperative drainage was smooth, and no anastomotic leakage, other complications, or animal deaths occurred.

Conclusions

The use of the intestine diversion tube with a double-balloon was feasible in animal experiments and was safe and effective. The procedure is simple, and suitable for popularization and application in the clinic.

Advances in pelvic imaging parameters predicting surgical difficulty in rectal cancer

Due to the fixed bony structure of the pelvis, the pelvic operation space is limited, complicating the surgical operation of rectal cancer, especially middle and low rectal cancer. The closer the tumor is to the anal verge, the smaller the operative field and operating space, the longer the operative time, and the greater the incidence of intraoperative side injuries and postoperative complications. To date, there is still no clear definition of a difficult pelvis that affects the surgical operation of rectal cancer. Few related research reports exist in the literature, and views on this aspect are not the same between countries. Therefore, it is particularly important to predict the difficulty of rectal cancer surgery in a certain way before surgery and to select the surgical method most suitable for each case during the treatment of rectal cancer.

2'-Fucosyllactose Suppresses Angiogenesis and Alleviates Toxic Effects of 5-Fu in a HCT116 Colon Tumor-Bearing Model

The present study was aimed at examining the anti-tumor effects and molecular mechanisms of 2'-fucosyllactose (2'-FL). At the beginning, the viabilities of four types of colon cancer cells were analyzed after exposure to increasing concentrations of 2'-FL, and HCT116 cells were selected as the sensitive ones, which were applied in the further experiments; then, interestingly, 2'-FL (102.35 µM) was found to induce apoptosis of HCT116 cells, which coincides with significant changes in VEGFA/VEGFR2/p-PI3K/p-Akt/cleaved Caspase3 proteins. Next, in a tumor-bearing nude mouse model, HCT116 was chosen as the sensitive cell line, and 5-fluorouracil (5-Fu) was chosen as the positive medicine. It was noteworthy that both 2'-FL group (2.41 ± 0.57 g) and 2'FL/5-Fu group (1.22 ± 0.35 g) had a significantly lower tumor weight compared with the control (3.87 ± 0.79 g), suggesting 2'-FL could inhibit colon cancer. Since 2'-FL reduced the number of new blood vessels and the malignancy of tumors, we confirmed that 2'-FL effectively inhibited HCT116 tumors, and its mechanism was achieved by regulating the VEGFA/VEGFR2/PI3K/Akt/Caspase3 pathway. Moreover, though HE staining and organ index measurement, 2'-FL was validated to alleviate toxic effects on liver and kidney tissue when combining with 5-Fu. In conclusion, 2'-FL had certain anti-tumor and detoxification effects.

Evaluation of Nursing Effects of Pelvic Floor Muscle Rehabilitation Exercise on Gastrointestinal Tract Rectal Cancer Patients Receiving Anus-preserving Operation by Intelligent Algorithm-based Magnetic Resonance Imaging

Based on magnetic resonance imaging (MRI) technology under artificial intelligence algorithm, the postoperative nursing effects of pelvic floor muscle rehabilitation exercise on gastrointestinal tract rectal cancer (RC) patients were investigated. A total of 88 patients receiving RC anus-preserving surgery in hospital were selected. The included patients were divided randomly into the experimental group (44 cases) and the control group (44 cases). Patients in the control group engaged in Kegel motion, while patients in the experimental group underwent self-designed comprehensive pelvic floor training. Anorectum function rating scale and quality of life questionnaire for colorectal cancer (EORTC QLQ-CR29) were utilized to compare and analyze anus functions and living quality of patients in the two groups. Besides, all patients in two groups received MRI examinations, and images were processed by a convolutional neural network (CNN) algorithm. The results showed that in MRI images, there were significant signal differences between lesion tissues and normal tissues. After being processed by an artificial intelligence algorithm, the definition of MRI images was remarkably enhanced with clearer lesion edges. The quality of images was also significantly improved. Besides, the comparison of anus functions of patients in two groups showed that the differences demonstrated statistical meaning after the intervention (P < 0.05). In conclusion, artificial intelligence algorithm-based MRI and comprehensive pelvic floor muscle exercise showed significant application prospects and values in the recovery of patients' intestinal functions after RC anus-preserving surgery.

Rationale and design of a prospective, multicenter, phase II clinical trial of safety and efficacy evaluation of long course neoadjuvant chemoradiotherapy plus tislelizumab followed by total mesorectal excision for locally advanced rectal cancer (NCRT-PD1-LARC trial)

BACKGROUND

Long course radiotherapy plus neoadjuvant chemotherapy followed by resection (total mesorectal excision, TME) has accepted widespread recognized in the treatment of locally advanced rectal cancer (LARC). Tislelizumab, an anti-PD1 humanized IgG4 monoclonal antibody, has been demonstrated with clinical activity and is approved for treating recurrent/refractory classical Hodgkin lymphoma and locally advanced/metastatic urothelial carcinoma in China. However, the safety and efficacy of long course (neoadjuvant chemoradiotherapy, NCRT) plus tislelizumab followed by TME for LARC is still uncertain.

METHODS

This NCRT-PD1-LARC trial will be a prospective, multicenter and phase II clinical trial designed to evaluate the safety and efficacy of LARC patients treated with long course NCRT plus tislelizumab followed by TME. This trial will consecutively enroll 50 stage II/III LARC patients (cT3N0M0 and cT1-3N1-2M0) with the tumor distal location ≤ 7 cm from anal verge at 7 centers in China. The enrolled patients will receive long course radiotherapy (50 Gy/25 f, 2 Gy/f, 5 days/week) and three 21-day cycles capecitabine (1000 mg/m2, bid, po, day1-14) plus three 21-day cycles tislelizumab (200 mg, iv.gtt, day8), followed by TME 6-8 weeks after the end of radiotherapy. The primary efficacy endpoint will be the pathological complete response (pCR) rate, which is defined as absence of viable tumor cells in the primary tumor and lymph nodes.

DISCUSSION

To our knowledge, this trial is the first multicenter clinical trial in China to assess the safety and efficacy of NCRT plus anti-PD1 therapy followed by TME to treat patients with LARC. NCRT followed by TME was recognized as the most recommended treatment against LARC while could not be completely satisfied in clinic. This study expects to provide a solid basis and encouraging outcomes for this promising combination of radiotherapy, chemotherapy and immunotherapy in LARC.

TRIAL REGISTRATION

Name of the registry: ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT04911517. Date of registration: 23 May 2021. URL of trial registry record: https://www.

CLINICALTRIALS

gov/ct2/show/NCT04911517?id=BFH-NCRTPD&draw=2&rank=1 .