Middle Rectal Cancer Research Articles

Predictive factors for pathological complete response to neoadjuvant therapy in locally advanced rectal cancer: a review of current research

The guidelines advocate for preoperative neoadjuvant radiotherapy and chemotherapy in cases of middle and low locally advanced rectal cancer. While some patients achieved pathological complete response (pCR), which is favorable and allows for potential organ preservation, treatment sensitivity varies and not all patients reach pCR. Identifying the factors influencing pCR is important for enhancing the effectiveness of neoadjuvant therapy and improving patient outcomes. Previous research has identified various factors associated with response to neoadjuvant therapy, which can serve as predictors of pCR. This study reviews recent literature on imaging, pathological, genetic, and molecular characteristics, laboratory indices, and therapeutic factors related to tumor response, both domestically and internationally. The aim is to summarize the latest advancements in understanding the factors associated with pCR in patients with locally advanced middle and low rectal cancer undergoing neoadjuvant therapy, thereby providing a theoretical foundation for standardized clinical treatment approaches.

A study of intersphincteric resection rate following robotic-assisted total mesorectal excision versus laparoscopic-assisted total mesorectal excision for patients with middle and low rectal cancer: study protocol for a multicenter randomized clinical trial

IntroductionRobotic-assisted complete mesorectal excision (RATME) is increasingly being used by colorectal surgeons. Most surgeons consider RATME a safe method, and believe it can facilitate total mesorectal excision (TME) in rectal cancer, and may potentially have advantages over intersphincteric resection (ISR) and anus preservation. Therefore, this trial was designed to investigate whether RATME has technical advantages and can increase the ISR rate compared with laparoscopic-assisted TME (LATME) in patients with middle and low rectal cancer.Methods and analysisThis is a multicenter, superiority, randomized controlled trial designed to compare RATME and LATME in middle and low rectal cancer. The primary endpoint is the ISR rate. The secondary endpoints are coloanal anastomosis (CAA) rate, conversion to open surgery, conversion to transanal TME (TaTME), abdominoperineal resection (APR) rate, postoperative morbidity and mortality within 30 days, pathological outcomes, long-term survival outcomes, functional outcomes, and quality of life. In addition, certain measurements will be conducted to ensure quality and safety, including centralized photography review and semiannual assessment.DiscussionThis trial will clarify if RATME improves ISR and promotes anus preservation in patients with mid- and low-rectal cancer. Furthermore, this trial will provide evidence on the optimal treatment strategies for RATME and LATME in patients with mid- and low-rectal cancer regarding improved operational safety.Trial registrationClinicalTrials.gov NCT06105203. Registered on October 27, 2023.

Node-sparing modified short-course Radiotherapy Combined with CAPOX and Tislelizumab for locally Advanced MSS of Middle and low rectal Cancer (mRCAT): an open-label, single-arm, prospective, multicentre clinical trial

BackgroundNeoadjuvant chemoradiotherapy followed by total mesorectal excision is a standard treatment for locally advanced rectal cancer. Mismatch repair-deficient locally advanced rectal cancer (LARC) was highly sensitive to PD-1 blockade. However, most rectal cancers are microsatellite stable (MSS) or mismatch repair-proficient (pMMR) subtypes for which PD-1 blockade is ineffective. Radiation can trigger the activation of CD8 + T cells, further enhancing the responses of MSS/pMMR rectal cancer to PD-1 blockade. Radioimmunotherapy offers a promising therapeutic modality for rectal cancer. Progenitor T exhausted cells are abundant in tumour-draining lymph nodes and play an important role in immunotherapy. Conventional irradiation fields include the mesorectum and regional lymph nodes, which might cause considerable damage to T lymphocytes and radiation-induced fibrosis, ultimately leading to a poor response to immunotherapy and rectal fibrosis. This study investigated whether node-sparing modified short-course irradiation combined with chemotherapy and PD-1 blockade could be effective in patients with MSS/ pMMR LARC.MethodsThis was a open-label, single-arm, multicentre, prospective phase II trial. 32 LARC patients with MSS/pMMR will receive node-sparing modified short-course radiotherapy (the irradiated planned target volume only included the primary tumour bed but not the tumour-draining lymph nodes, 25 Gy/5f, 5 Gy/f) followed by CAPOX and tislelizumab. CAPOX and tislelizumab will be started two days after the completion of radiotherapy: oxaliplatin 130 mg/m2 intravenous infusion, day 1; capecitabine 1000 mg/m2 oral administration, days 1–14; and tislelizumab 200 mg, intravenous infusion, day 1. There will be four 21-day cycles. TME will be performed at weeks 14–15. We will collect blood, tumour, and lymphoid specimens; perform flow cytometry and in situ multiplexed immunofluorescence detection; and analyse the changes in various lymphocyte subsets. The primary endpoint is the rate of pathological complete response. The organ preservation rate, tumour regression grade, local recurrence rate, disease-free survival, overall survival, adverse effects, and quality of life will also be analysed.DiscussionIn our research, node-sparing modified radiotherapy combined with immunotherapy probably increased the responsiveness of immunotherapy for MSS/pMMR rectal cancer patients, reduced the occurrence of postoperative rectal fibrosis, and improved survival and quality of life. This is the first clinical trial to utilize a node-sparing radiation strategy combined with chemotherapy and PD-1 blockade in the neoadjuvant treatment of rectal cancer, which may result in a breakthrough in the treatment of MSS/pMMR rectal cancer.Trial registrationThis study was registered at www.clinicaltrials.gov. Trial registration number: NCT05972655. Date of registration: 31 July 2023.

Development and validation of an MRI and clinicopathological factors prediction model for low anterior resection syndrome in anterior resection of middle and low rectal cancer

ObjectiveTo validate the predictive power of newly developed magnetic resonance (MR) morphological and clinicopathological risk models in predicting low anterior resection syndrome (LARS) 6 months after anterior resection of middle and low rectal cancer (MLRC). MethodsFrom May 2018 to January 2021, 236 patients with MLRC admitted to two hospitals (internal and external validation) were included. MR images, clinicopathological data, and LARS scores (LARSS) were collected. Tumor morphology data included longitudinal involvement length, maximum tumor diameter, proportion of tumor to circumference of the intestinal wall, tumor mesorectal infiltration depth, circumferential margin status, and distance between the tumor and anal margins. Pelvic measurements included anorectal angle, mesenterial volume (MRV), and pelvic volume. Univariate and multivariate logistic regression was used to obtain independent risk factors of LARS after anterior resection Then, the prediction model was constructed, expressed as a nomogram, and its internal and external validity was assessed using receiver operating characteristic curves. ResultsThe uni- and multivariate analysis revealed distance between the tumor and anal margins, MRV, pelvic volume, and body weight as significant independent risk factors for predicting LARS. From the nomogram, the area under the curve (AUC), sensitivity, and specificity were 0.835, 75.0 %, and 80.4 %, respectively. The AUC, sensitivity, and specificity in the external validation group were 0.874, 83.3 %, and 91.7 %, respectively. ConclusionThis study shows that MR imaging and clinicopathology presented by a nomogram can strongly predict LARSS, which can then individually predict LARS 6 months after anterior resection in patients with MLRC and facilitate clinical decision-making. Clinical relevance statementWe believe that our study makes a significant contribution to the literature. This method of predicting postoperative anorectal function by preoperative measurement of MRV provides a new tool for clinicians to study LARS.

Prediction of postoperative complications following transanal total mesorectal excision in middle and low rectal cancer: development and internal validation of a clinical prediction model

PurposeThe objective of this study is to develop a nomogram for the personalized prediction of postoperative complication risks in patients with middle and low rectal cancer who are undergoing transanal total mesorectal excision (taTME). This tool aims to assist clinicians in early identification of high-risk patients and in addressing preoperative risk factors to enhance surgical safety.MethodsIn this case–control study, 207 patients diagnosed with middle and low rectal cancer and undergoing taTME between February 2018 and November 2023 at The First Affiliated Hospital of Xiamen University were included. Independent risk factors for postoperative complications were analyzed using the Least Absolute Shrinkage and Selection Operator (LASSO) regression and multifactorial logistic regression models. A predictive nomogram was constructed using R Studio.ResultsAmong the 207 patients, 57 (27.5%) experienced postoperative complications. The LASSO and multifactorial logistic regression analyses identified operation time (OR = 1.010, P = 0.007), smoking history (OR = 9.693, P < 0.001), anastomotic technique (OR = 0.260, P = 0.004), and ASA score (OR = 9.077, P = 0.051) as significant predictors. These factors were integrated into the nomogram. The model's accuracy was validated through receiver operating characteristic curves, calibration curves, consistency indices, and decision curve analysis.ConclusionThe developed nomogram, incorporating operation time, smoking history, anastomotic technique, and ASA score, effectively forecasts postoperative complication risks in taTME procedures. It is a valuable tool for clinicians to identify patients at heightened risk and initiate timely interventions, ultimately improving patient outcomes.

The Role of Lateral Pelvic Lymph Node Dissection in Middle and Lower Rectal Cancer (Stage II or III): A Literature Review.

Lateral lymph node dissection and its inclusion in the treatment of rectal cancer is a controversial issue, with great differences, especially between Eastern and Western countries. Studies try to highlight the superiority of resection of these lymph nodescompared to simple mesorectal resectionin terms of local recurrence of the disease, the overall survival of patients, and additional postoperative complications. In this study, the modern literature was reviewed, with the ultimate goal of clarifying the exact importance of lateral lymph node dissection, in terms of oncological outcome in patients with cancer of the middle and lower rectum, by studying the involvement of this lymph node dispersion in terms of local recurrence and overall survival of patients with rectal cancer. This review was carried out using electronic databases, including PubMed, Embase, and MEDLINE, with studies dating back to the last decade. Of the 31 studies that were eventually included in the final review, there is no statistically clear superiority and real benefit from lymph node resection beyond the lymph nodes of the mid-rectum. European guidelines are set against lateral lymph node dissection, except for lymph nodes that show suspicious features on preoperative imaging. In contrast, in Eastern countries, total mesorectal excision (TME) with extensive simultaneous resection of the lateral pelvic lymph nodes (LPLNs) is the protocol followed. Recent studies focus on the subcategory of patients with non-responsive to adjuvant therapy, lateral lymph nodes, in which the ultimate benefit of extensive lymph node dissection is explored. The decision to join the TME procedure for the removal of the LPLNs is a subject of intense research. There are no data on the criteria for determining these lymph nodes as an increased risk of metastatic outbreaks. Despite the great clinical and research interest worldwide nowadays, the resection of LPLNs remains a controversial issue of debate, with intense disagreements according to geographical area, while the existence of additional studies is necessary to come to final conclusions.

Application value of artificial intelligence in surgical precision diagnosis and treatment of rectal cancer

Colorectal cancer is the most common malignant tumor of digestive tract, and the incidence of colorectal cancer in China is especially characterized by middle and low rectal cancer. In recent years, with the progress of computer science, artificial intelligence technology has developed rapidly, and has achieved a lot of application results in the medical field. At present, artificial intelligence technology has covered various stages of colorectal cancer, including screening, individualized assessment, auxiliary diagnosis and treatment decision-making, refined surgery and prognosis judgment, providing help for the accurate and individualized treatment of rectal cancer. However, the lack of standardized, systematic, and scalable AI models remains a major pain point for the field. Therefore, it is necessary to carry out large-scale prospective clinical studies on artificial intelligence model to further confirm its application value in the clinical diagnosis and treatment of rectal cancer.

Evaluating Postoperative Prognosis: A Single Surgeon's Experience With Total Mesorectal Excision in Middle and Lower Rectal Cancer Cases in Iraq.

Surgical intervention for rectal cancer is widely recognized for its potential to significantly impact quality of life, chiefly due to the high probability of permanent colostomy and the associated postoperative complications. This study aimed to evaluate the short-term outcomes and morbidity associated with total mesorectal excision for middle and lower rectal cancer within an Iraqi cohort, in a prospective setting. This study prospectively collected and analyzed data from 89 patients who underwent a standardized radical rectal resection, with a follow-up period extending to one month post-surgery. The mean age of patients was 54.4 ± 12.9 years, with a gender distribution of 46 males and 43 females. A total of 33 patients presented with preoperative comorbidities, which heightened the risk of adverse short-term outcomes by a factor of 7.51. The most prevalent comorbidities were hypertension and diabetes mellitus, affecting 22 and 20 patients, respectively. Patients aged 60 years and above were at a 3.97 times greater risk of developing complications. The overall complication rate was 21.35%, with wound infections (9.0%) and cardiovascular events (3.4%) being the most common. Mortality during the follow-up was 1.1%. The findings indicate that increased age and the presence of comorbidities are significant risk factors for morbidity and mortality post-surgery. Neoadjuvant chemoradiotherapy or radiotherapy was shown to reduce morbidity and mortality rates while improving survival. The morbidity and mortality rates observed in this study concur with existing literature.

Robotic versus laparoscopic surgery for middle and low rectal cancer (REAL): Primary outcome of a multicenter randomized controlled trial.

3617 Background: Robotic surgery for rectal cancer is gaining popularity, but persuasive evidence on long-term oncological outcomes is lacking. This multicenter randomized controlled trial compared robotic and conventional laparoscopic surgery regarding surgical quality and long-term oncological outcomes among patients with middle and low rectal cancer. Previously the short-term outcomes of this trial had been reported that robotic surgery had significantly lower circumferential resection margin positivity rate, lower postoperative complication rate, and better postoperative recovery. Now the long-term oncological outcomes were reported. Methods: This superiority trial was undertaken at 11 hospitals in 8 Chinese provinces. Patients with middle (&gt; 5–10 cm from anal verge) or low (0–5 cm from anal verge) rectal adenocarcinoma, cT1–T3 N0–1 or ycT1–T3 Nx after preoperative radio-/chemoradiotherapy, and no evidence of distant metastasis were enrolled and randomly assigned in a 1:1 ratio to receive robotic or conventional laparoscopic surgery. The 3-year locoregional recurrence rate was the primary outcome and was compared using modified intention-to-treat (mITT) analysis. Secondary outcomes included disease-free survival and overall survival. All time-to-event outcomes were calculated using Kaplan-Meier method with log-rank test. This trial was registered with ClinicalTrials.gov (NCT02817126). Results: Between July 2016 and December 2020, 1240 patients were enrolled, and 1171 were included in the mITT analysis (586 in robotic and 585 in laparoscopic group). The pathological TNM stage of the mITT population was 73 (6.2%) patients with complete response, 346 (29.5%) with stage I, 368 (31.4%) with stage II, 384 (32.8%) with stage III. And the median follow-up time was 43.0 months (interquartile range = 36.7 to 60.0), with 34 (2.9%) patients lost to follow-up. The 3-year locoregional recurrence rate in robotic group (1.5%) was significantly lower than in laparoscopic group (4.0%, log-rank p=0.025, hazard ratio = 0.451, 95% confidence interval = 0.221 to 0.921). Robotic group also had significantly higher 3-year disease-free survival rate (87.3% vs. 83.6%, log-rank p=0.035). No significant difference was observed in 3-year overall survival rate (94.8% vs. 93.1%, log-rank p=0.155). Conclusions: Robotic surgery for middle and low rectal cancer significantly reduced locoregional recurrence and improved disease-free survival, compared with conventional laparoscopic surgery. Clinical trial information: NCT02817126 .

Clinical value of nano-carbon lymphatic tracer for regional lymph node dissections of rectal cancer after neoadjuvant chemoradiotherapy.

Regional lymph node (LN) volume decreases after neoadjuvant therapy, requiring a tracer for more accurate detection. Nano-carbon tracer is a third-generation tracer with several advantages, but its use for LN detection after neoadjuvant chemoradiotherapy for middle and low rectal cancer remains unclear. Therefore, this study investigated the effects and safety of anoscope-guided subrectal injections of nano-carbon suspension in this patient population. This study retrospectively reviewed the medical records of 45 patients with middle and low rectal cancer admitted to our institution from March 2019 to March 2022. All patients received preoperative neoadjuvant chemotherapy and radiotherapy and were divided into nano-carbon injection (n=23; anoscope-guided injections of nano-carbon suspension in the rectal submucosa 2cm above the dentate line 24h preoperatively) and control (n=22; directly underwent surgery) groups. The LN detection and complication rates were compared between the groups. The total and mean numbers of LNs and small LNs and the number of patients with>12 LNs were significantly higher in the nano-carbon injection group than in the control group. The total number of positive LNs and LN metastasis did not differ between the groups, nor did the anastomotic leakage, bleeding, stenosis, and abscess occurrence rates. Anoscope-guided nano-carbon lymphatic tracing increased the LN detection rate, caused less trauma, and resulted in fewer postoperative complications than the direct surgical procedure. Thus, it is an effective, safe, and practical method that may improve dissections and the postoperative pathological staging accuracy.

LASSO-based nomogram predicts the risk factors of low anterior resection syndrome for middle and low rectal cancer underwent robotic surgery.

This study aims to analyze the influencing factors of postoperative Low Anterior Resection Syndrome (LARS) in patients with middle and low rectal cancer who underwent robotic surgery. It also seeks to predict the probability of LARS through a visual, quantitative, and graphical nomogram. This approach is expected to lower the risk of postoperative LARS in these patients and improve their quality of life through effective prevention and early intervention. This research involved patients with middle and low rectal cancer who underwent robotic surgery in the Department of Gastrointestinal Surgery at the First Affiliated Hospital of Nanchang University from January 2015 to October 2022. A series of intestinal dysfunction symptoms arising from postoperative rectal cancer were diagnosed and graded using LARS scoring criteria. After the initial screening of all variables related to LARS with Lasso regression, they were included in logistic regression for further univariate and multivariate analysis to identify independent risk factors for LARS. A prediction model was then constructed. The study included 358 patients. The parameters identified by Lasso regression included obstruction, BMI, tumor localization, maximum tumor diameter, AJCC stage, stoma, neoadjuvant therapy (NAT), and postoperative adjuvant therapy (AT). Univariate and multivariate analyses indicated that a higher BMI, lower tumor localization, higher AJCC stage, neoadjuvant therapy, and postoperative adjuvant therapy were independent risk factors for total LARS. The AUC of the prediction nomogram was 0.834, with a sensitivity of 0.825 and specificity of 0.741. The calibration curve demonstrated excellent concordance with the nomogram, indicating the prediction curve fit the diagonal well. Higher BMI, lower tumor localization, higher AJCC stage, neoadjuvant therapy, and adjuvant therapy were identified as independent risk factors for total LARS. A new predictive nomogram for postoperative LARS in patients with middle and low rectal cancer undergoing robotic surgery was developed, proving to be stable and reliable. This tool will assist clinicians in managing the postoperative treatment of these patients, facilitating better clinical decision-making and maximizing patient benefits.

Intersphincteric resection following robotic-assisted versus laparoscopy-assisted total mesorectal excision for middle and low rectal cancer: a multicentre propensity score analysis of 1571 patients.

Robotic-assisted total mesorectal excision (RaTME) may be associated with reduced conversion to an open approach and a higher rate of complete total mesorectal excision (TME); however, studies on its advantages in intersphincteric resection (ISR) are inadequate. This retrospective multicenter cohort study enroled consecutive patients who underwent RaTME and laparoscopy-assisted total mesorectal excision (LaTME) at four medical centres between January 2020 and March 2023. Propensity score matching (PSM), inverse probability of treatment weight (IPTW), and multivariate logistic regression analyses were performed. The primary outcome was the ISR rate. Secondary outcomes were coloanal anastomosis (CAA), conversion to open surgery, conversion to transanal TME, abdominoperineal resection, postoperative morbidity and mortality within 30 days, and pathological outcomes. Among the 1571 patients, 1211 and 450 underwent LaTME and RaTME, respectively, with corresponding ISR incidences of 5.3% and 8.4% ( P =0.024). After PSM and IPTW, RaTME remained associated with higher ISR rates (4.5% versus 9.4%, P =0.022 after PSM; 4.9% versus 9.2, P =0.005 after IPTW). This association remained in multivariate analysis after adjusting for other confounding factors. RaTME was further associated with a higher CAA rate, longer operating time, and higher hospitalization expenses. RaTME may facilitate ISR in middle and low rectal cancers, showing an independent association with a higher ISR incidence, with pathological outcomes and complications comparable to those of LaTME. However, it may also require a longer operating time and incur higher hospitalization expenses.

Long-term bowel functional outcomes following anal sphincter-preserving surgery for upper and middle rectal cancer: a single-center longitudinal study.

Despite advances in neoadjuvant chemoradiotherapy and anal sphincter-preserving surgery for rectal cancer, bowel dysfunction is still unavoidable and negatively affects patients' quality of life. In this longitudinal study, we aimed to investigate the changes in bowel function with follow-up time and the effect of neoadjuvant chemoradiotherapy on bowel function following low anterior resection for rectal cancer. In this study, 171 patients with upper or middle rectal cancer who underwent low anterior resection between 2012 and 2018 were included. Bowel function was assessed longitudinally with Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores every 6 months after restoration of bowel continuity. Patients with at least 2 follow-up visits were included. Overall, 100 patients received neoadjuvant chemoradiotherapy. Urgency, soilage, and fecal incontinence were noted within 24 months in the patients treated with neoadjuvant chemoradiotherapy. After 2 years of follow-up, significant bowel dysfunction and fecal incontinence were observed in the neoadjuvant chemoradiotherapy group. Low tumor level and neoadjuvant chemoradiotherapy were associated with delayed bowel dysfunction. Neoadjuvant chemoradiotherapy in combination with low tumor level was significantly associated with delayed bowel dysfunction even after 2 years of follow-up. Therefore, careful selection and discussion with patients are paramount.

A modified method for precise anastomosis during laparoscopic low anterior resection for rectal cancer: the first clinical experience and application

BackgroundThere is no criterion to guide and evaluate the anastomosis of laparoscopic low anterior resection (LAR). We developed a new technique for precise anastomosis. This study endeavored to evaluate the effectiveness and safety of this new technology.MethodsPatients with mid-low rectal cancer who underwent laparoscopic LAR in our department were enrolled retrospectively between January 1, 2021 and July 1, 2023. During the LAR, the distance between the sacral promontory and the rectal stump was measured and used to determine the length of the sigmoid colon, which was preserved for anastomose. The demographic characteristics and short-term outcomes were analyzed.ResultsForty-nine patients (26 men, 23 women) with low and middle rectal cancer were retrospectively enrolled in the study. The distance of the tumor from the anal verge was 6.4 ± 2.7 cm. The operative time was 193 ± 42 min. All patients underwent precise anastomosis, among which 12 patients underwent freeing of the splenic flexure of the colon. According to our criteria, there was no redundant or tense state of the colon anterior to the sacrum after the anastomosis. Only one patient had a postoperative anastomotic leak (Grade B). All 15 patients receiving neoadjuvant chemoradiotherapy underwent terminal ileostomy. No postoperative death occurred within 30 days of the surgery. The median follow-up time in our study was 12 months. One patient developed a single metastasis in the right lobe of the liver in the eighth month after surgery and underwent microwave radiofrequency ablation, which did not recur in the four months of postoperative follow-up, and the rest of the patients survived disease-free without recurrence of metastasis.ConclusionsPrecise measurement of the proximal colon of the anastomosis can ensure accurate and convenient colorectal anastomosis and this may be a technique worthy of clinical application. However, its effectiveness needs to be further verified in a multicenter clinical trial.

Node-sparing modified short-course radiotherapy combined with CAPOX and tislelizumab for locally advanced MSS of middle and low rectal cancer (mRCAT): An open-label, single-arm, prospective, multicentre clinical trial.

TPS233 Background: Neoadjuvant chemoradiotherapy followed by total mesorectal excision is a standard treatment for locally advanced rectal cancer. Mismatch repair-deficient locally advanced rectal cancer was highly sensitive to PD-1 blockade. However, most rectal cancers are mismatch repair-proficient or microsatellite stable subtypes for which PD-1 blockade is ineffective. Radiation can trigger the activation of CD8+ T cells, further enhancing the responses of microsatellite stable rectal cancer to PD-1 blockade. Radioimmunotherapy offers a promising therapeutic modality for rectal cancer. Progenitor T exhausted cells are abundant in tumour-draining lymph nodes and play an important role in immunotherapy. Conventional irradiation fields include the mesorectum and regional lymph nodes, which might cause considerable damage to T lymphocytes and radiation-induced fibrosis, ultimately leading to a poor response to immunotherapy and rectal fibrosis. This study investigated whether node-sparing modified short-course irradiation combined with chemotherapy and PD-1 blockade could be effective in patients with microsatellite stable locally advanced rectal cancer. Methods: Our clinical trial investigates the safety and efficacy of node-sparing modified short-course radiotherapy combined with CAPOX and tislelizumab for microsatellite stable locally advanced middle and low rectal cancer. This phase II study will recruit 32 patients to receive node-sparing modified short-course radiotherapy (the irradiated planned target volume only included the primary tumour bed but not the tumour-draining lymph nodes, 25 Gy/5f, 5 Gy/f) followed by CAPOX and tislelizumab. 2 of planned 32 patients have been enrolled. CAPOX and tislelizumab will be started two days after the completion of radiotherapy: oxaliplatin 130 mg/m2 intravenous infusion, day 1; capecitabine 1000 mg/m2 oral administration, days 1-14; and tislelizumab 200 mg, intravenous infusion, day 1. There will be three 21-day cycles. TME will be performed at weeks 11-12. We will collect blood, tumour, and lymphoid specimens; perform flow cytometry and in situ multiplexed immunofluorescence detection; and analyse the changes in various lymphocyte subsets. The primary endpoint is the rate of pathological complete response. The organ preservation rate, tumour regression grade, local recurrence rate, disease-free survival, overall survival, adverse effects, and quality of life will also be analysed. Clinical trial information: NCT05972655 .

The effectiveness and safety of rectal modular dissection for male middle and low rectal cancer after neoadjuvant chemoradiation therapy: the short-term outcome.

Background: The purpose of this study was to assess the efficacy and safety of rectal modular dissection (RMD) in male patients with middle and low rectal cancer. RMD is a technique used to guide the surgical procedure for rectal mobilization, with the ultimate goal of achieving total mesorectal excision. In order to evaluate the effectiveness of RMD, a single-center, non-inferiority randomized clinical trial was carried out. Methods: Eligible patients were randomly assigned into two groups: the RMD group and the traditional rectal mobilization (TRM) group. Demographic characteristics, perioperative data and pathological results of the surgical specimens were collected for analysis. additionally, assessments of urogenital function and defecation function were conducted for all participants. Results: A total of 103 patients (RMD group 53 patients and TRM group 50 patients) were included to analyzed. There were no significant differences in age, body mass index, ASA classification, and tumor characteristics between two groups. The RMD group had significantly lower blood loss (P = 0.00), shorter operative duration (P = 0.00), and shorter hospital stay (P = 0.04) compared to the TRM group. The complete rate of mesorectal excision was higher in the RMD group (98.1%) compared to the TRM group (86.0%, P = 0.02). In terms of functional outcomes, the RMD group had better evaluation scores for urethral function (IPSS score, P = 0.01), erectile function (IIEF-5 score, P = 0.00) and defecation function (LARS score, P = 0.00) at the one-year postoperative follow-up. The 1-year disease-free survival rate was similar between the two groups (P = 0.28). Conclusions: These results suggest that RMD is an effective and safe approach for achieving total mesorectal excision while promoting better functional outcomes for patients. The trial was registered in Chinese Clinical Trial Registry (ChiCTR2100052094).

Distal margin distance in radical resection of locally advanced rectal cancer after neoadjuvant therapy.

Colorectal cancer has a high incidence and mortality rate in China, with the majority of cases being middle and low rectal cancer. Surgical intervention is currently the main treatment modality for locally advanced rectal cancer, with the common goal of improving oncological outcomes while preserving function. The controversy regarding the circumferential resection margin distance in rectal cancer surgery has been resolved. With the promotion of neoadjuvant therapy concepts and advancements in technology, treatment strategies have become more diverse. Following tumor downstaging, there is an increasing trend towards extending the safe distance of distal rectal margin. This provides more opportunities for patients with low rectal cancer to preserve their anal function. However, there is currently no consensus on the specific distance of distal resection margin.

Problems of preoperative diagnosis of pelvic lymph node lesions in rectal cancer (review)

Background: metastasis in lateral pelvic lymph nodes (LPLN) occurred in 6–15% of patients with middle or low rectal cancer. Currently there are still no criteria of diagnosis of this. There is no generally accepted management this group of the patients.Aim: to systematize the available literature data about lateral pelvic lymph node dissection in patients with rectal cancer.Materials and Methods: literature search was performed in the PubMed and e-Library databases using the keywords: LLND, lateral lymph node, rectal cancer, lymphodissection. The search date: July 2023.Results: preoperative CRT with total mesorectumectomy supplemented with selective LTLD for suspected metastases seems to be a rational strategy to achieve a favorable oncological treatment outcome.Conclusion: Additional studies are required.

The importance of preoperative T3 stage substaging by 3D endorectal ultrasonography for the prognosis of middle and low rectal cancer.

The study aimed to validate the role of 3D-endorectal ultrasonography in prognosis and recurrence for patients with T3-stage rectal cancer by evaluating the preoperative extramural depth of tumor invasion. In this study, we investigated the medical records of rectal cancer patients who were admitted to Changhai Hospital's Colorectal Surgery Division. The sample group was categorized into three subgroups (T3a, T3b, and T3c) based on the extent of tumor progression (<5 mm, 5-10 mm, and >10 mm) to assess the endorectal ultrasonography diagnostic performance. The 5-year disease-free survival and overall survival were assessed using the Kaplan-Meier method and a log rank test. Cox regression analysis verified the tumor invasion depth's significance as a prognostic predictor, and it was also utilized to evaluate other independent risk variables for recurrence after surgery. The study included 72 individuals with low and middle rectal cancer from January 2014 to November 2019. Twenty-two individuals had stage T3a, 22 had stage T3b, and 28 had stage T3c based on preoperative endorectal ultrasonography. Endorectal ultrasonography had 88.0%, 86.8%, and 76.2% overall accuracy for stratifying subgroups, respectively. According to the Kaplan-Meier curve, 5-year OS was 100%, 83.5%, and 92.9% for T3a, T3b, and T3c (p = 0.172), and 5-year disease-free survival was 100%, 80.8%, and 72.9% for T3a, T3b, and T3c, respectively (p = 0.014). A distinct risk factor for 5-year disease-free survival was the degree of tumor infiltration (p = 0.039). Preoperative T3 stage subdivision allows for categorization of prognosis and survival. Endorectal ultrasonography reports should make explicit declarations of T3a, T3b, and T3c scales.

Development of a joint prediction model based on both the radiomics and clinical factors for preoperative prediction of circumferential resection margin in middle-low rectal cancer using T2WI images.

A circumferential resection margin (CRM) is an independent risk factor for local recurrence, distant metastasis, and poor overall survival of rectal cancer. In this study, we developed and validated a radiomics prediction model to predict perioperative surgical margins in patients with middle and low rectal cancer following neoadjuvant treatment and for decisions about treatment plans for patients. This study retrospectively analyzed 275 patients from center 1(training cohort) and 120 patients from center 2(verification cohort) with rectal cancer diagnosed at two centers from July 2020 to July 2022 who underwent neoadjuvant therapy and had their CRM status confirmed by preoperative high-resolution magnetic resonance imaging (MRI) scans. Radiomics signatures were extracted and screened from MRI images and a radiomics signature was built by the least absolute shrinkage and selection operator (LASSO) logistic regression model, which was combined with clinical signatures to construct a nomogram. The receiver operating characteristic (ROC) curve and area under the curve (AUC) value, sensitivity, specificity, positive predictive value, negative predictive value, and calibration curve were used to evaluate the predictive performance of the model. In our research, the combined model has the best performance. In the training group, the radiomics model based on high-spatial-resolution T2-weighted imaging (HR-T2WI), clinical model and combined model demonstrated an AUC of 0.819 (0.802-0.833), 0.843 (0.822-0.861), and 0.910 (0.880-0.940), respectively. In the validation group, they demonstrated an AUC of 0.745 (0.715-0.788), 0.827 (0.798-0.850), and 0.848 (0.779-0.917), respectively. The calibration curve confirmed the clinical applicability of the model. The individualized prediction model established by combining radiomics signatures and clinical signatures can efficiently and objectively predict perioperative margin invasion in patients with middle and low rectal cancer.