Effect of preoperative injection of carbon nanoparticle suspension on the outcomes of selected patients with mid-low rectal cancer

Background:Carbon nanoparticles show significant lymphatic tropism and can be used to identify lymph nodes surrounding mid-low rectal tumors.In this study,we analyzed the effect of trans anal injection of a carbon nanoparticle suspension on the outcomes of patients with mid-low rectal cancer who underwent laparoscopic resection.Methods:We collected the data of 87 patients with mid-low rectal cancer who underwent laparoscopic resection between November 2014 and March 2015 at Cancer Hospital,Chinese Academy of Medical Sciences & Peking Union Medical College.For 35 patients in the experimental group,the carbon nanoparticle suspension was injected transanally into the submucosa of the rectum around the tumor 30 min before the operation;52 patients in the control group underwent the operation directly without the injection of carbon nanoparticle suspension.We then compared the operation outcomes between the two groups.Results:In the experimental group,the rate of incomplete mesorectal excision was lower than that in the control group,but no significant difference was found(2.9%vs.7.7%,P = 0.342).The distance between the tumor and the circumferential resection margin was 5.8 ± 1.4 mm in the experimental group and 4.8 ±1.1 mm in the control group(P = 0.001).The mean number of lymph nodes removed was 28.2 ± 9.4 in the experimental group and 22.7 ± 7.3in the control group(P = 0.003);the mean number of lymph nodes smaller than 5 mm in diameter was 10.1 ± 7.5and 4.5 ±3.7,respectively(P< 0.001).Three patients in the experimental group received lateral lymph node resection.Among the three patients,we retrieved three nodes(one stained node) from the first patient,three nodes(two stained nodes) from the second patient,and two nodes(no stained nodes) from the third patient.Conclusions:Injecting a carbon nanoparticle suspension improved the outcomes of patients who underwent laparoscopic resection for mid-low rectal cancer;it also improved the accuracy of pathologic staging.Moreover,for selected patients,this technique narrowed the scope of lateral lymph node dissection.

Anorectal dysfunction in patients with mid-low rectal cancer after surgery: A pilot study with three-dimensional high-resolution manometry

BACKGROUND The quality of life in patients who develop low anterior resection syndrome(LARS)after surgery for mid-low rectal cancer is seriously impaired.The underlying pathophysiological mechanism of LARS has not been fully investigated.AIM To assess anorectal function of mid-low rectal cancer patients developing LARS perioperatively.METHODS Patients diagnosed with mid-low rectal cancer were included.The LARS score was used to evaluate defecation symptoms 3 and 6 mo after anterior resection or a stoma reversal procedure.Anorectal functions were assessed by threedimensional high resolution anorectal manometry preoperatively and 3-6 mo after surgery.RESULTS The study population consisted of 24 patients.The total LARS score was decreased at 6 mo compared with 3 mo after surgery(P<0.05),but 58.3%(14/24)lasted as major LARS at 6 mo after surgery.The length of the high-pressure zone of the anal sphincter was significantly shorter,the mean resting pressure and maximal squeeze pressure of the anus were significantly lower than those before surgery in allpatients (P < 0.05), especially in the neoadjuvant therapy group after surgery (n = 18). The focalpressure defects of the anal canal were detected in 70.8% of patients, and those patients had higherLARS scores at 3 mo postoperatively than those without focal pressure defects (P < 0.05). Spasticperistaltic contractions from the new rectum to anus were detected in 45.8% of patients, whichwere associated with a higher LARS score at 3 mo postoperatively (P < 0.05).CONCLUSIONThe LARS score decreases over time after surgery in the majority of patients with mid-low rectalcancer. Anorectal dysfunctions, especially focal pressure defects of the anal canal and spasticperistaltic contractions from the new rectum to anus postoperatively, might be the majorpathophysiological mechanisms of LARS.

Evaluation of the Diagnostic Value of Digital Rectal Examination for Lymph Node Metastasis in Mid-Low Rectal Cancer

Background: NCCN’s guidelines for the diagnosis and treatment of rectal cancer suggest that accurate preoperative clinical staging of rectal cancer is very important. Reliable preoperative evaluation is the key to the development of surgical protocols, in order to investigate the diagnostic value of digital rectal diagnosis for lymph node metastasis of middle and low rectal cancer. Methods: We prospectively performed digital rectal examination in 258 patients with mid-low rectal cancer before operation, to analyze the distance from the lower margin of the tumor to the margin of the anus, the diameter of the invasion of the intestinal wall of the tumor, the accuracy between the general type and depth of invasion of the tumor and the pathological results of the postoperative specimen, and the predictability of the lymph node metastasis rate of the rectal digital examination. Results: The results of the analysis showed that the above indicators and postoperative pathological findings have high accuracy. Conclusions: It is concluded that accurate and detailed digital rectal examination before operation can predict lymph node metastasis rate of mid-low rectal cancer at a higher level and accurately.

Multiparameter magnetic resonance imaging-based radiomics model for the prediction of rectal cancer metachronous liver metastasis

BACKGROUND The liver,as the main target organ for hematogenous metastasis of colorectal cancer,early and accurate prediction of liver metastasis is crucial for the diagnosis and treatment of patients.Herein,this study aims to investigate the application value of a combined machine learning(ML)based model based on the multiparameter magnetic resonance imaging for prediction of rectal metachronous liver metastasis(MLM).AIM To investigate the efficacy of radiomics based on multiparametric magnetic resonance imaging images of preoperative first diagnosed rectal cancer in predicting MLM from rectal cancer.METHODS We retrospectively analyzed 301 patients with rectal cancer confirmed by surgical pathology at Jingzhou Central Hospital from January 2017 to December 2023.All participants were randomly assigned to the training or validation queue in a 7:3 ratio.We first apply generalized linear regression model(GLRM)and random forest model(RFM)algorithm to construct an MLM prediction model in the training queue,and evaluate the discriminative power of the MLM prediction model using area under curve(AUC)and decision curve analysis(DCA).Then,the robustness and generalizability of the MLM prediction model were evaluated based on the internal validation set between the validation queue groups.RESULTS Among the 301 patients included in the study,16.28%were ultimately diagnosed with MLM through pathological examination.Multivariate analysis showed that carcinoembryonic antigen,and magnetic resonance imaging radiomics were independent predictors of MLM.Then,the GLRM prediction model was developed with a comprehensive nomogram to achieve satisfactory differentiation.The prediction performance of GLRM in the training and validation queue was 0.765[95%confidence interval(CI):0.710-0.820]and 0.767(95%CI:0.712-0.822),respectively.Compared with GLRM,RFM achieved superior performance with AUC of 0.919(95%CI:0.868-0.970)and 0.901(95%CI:0.850-0.952)in the training and validation queue,respectively.The DCA indicated that the predictive ability and net profit of clinical RFM were improved.CONCLUSION By combining multiparameter magnetic resonance imaging with the effectiveness and robustness of ML-based predictive models,the proposed clinical RFM can serve as an insight tool for preoperative assessment of MLM risk stratification and provide important information for individual diagnosis and treatment of rectal cancer patients.

Discovery of primary lung cancer following resection of rectal cancer lung metastasis:A case report

BACKGROUND Colorectal cancer(CRC)ranks high among the most common types of malignant tumors.The primary cause of cancer-related mortality is metastasis,with lung metastases accounting for 32.9%of all cases of metastatic CRC(MCRC).However,cases of MCRC in the lungs,which present concurrently with primary peripheral lung adenocarcinoma,are exceptionally rare.CASE SUMMARY This report describes the case of a 52-year-old female patient who,following a colonoscopy,was diagnosed with moderately differentiated adenocarcinoma based on rectal mucosal biopsy findings.A preoperative chest computed tomography scan revealed a ground-glass nodule in the right lung and a small nodule(approximately 0.6 cm in diameter)in the extramural basal segment of the left lower lobe,which suggested multiple lung metastases from rectal cancer.Subsequent treatment and follow-up led to a diagnosis of rectal cancer with left lung metastasis and peripheral adenocarcinoma of the lower lobe of the right lung.CONCLUSION This case report describes the therapeutic journey of a patient with lung metastasis from rectal cancer in addition to primary peripheral adenocarcinoma,thus underscoring the critical roles of multidisciplinary collaboration,personalized treatment strategies,and comprehensive patient rehabilitation guidance.

Current and future perspectives in the management and treatment of colorectal cancer

In this editorial,we reviewed the article by Fadlallah et al that was recently published in the World Journal of Clinical Oncology.The article provided a comprehensive and in-depth view of the management and treatment of colorectal cancer(CRC),one of the leading causes of cancer-related morbidity and mortality worldwide.The article analyzed the therapeutic modalities and their sequencing,focusing on total neoadjuvant therapy for locally advanced rectal cancer.It highlighted the role of immunotherapy in tumors with high microsatellite instability or deficient mismatch repair,addressing recent advances that have improved prognosis and therapeutic response in localized and metastatic CRC.Innovations in surgical techniques,advanced radiotherapy,and systemic agents targeting specific mutational profiles are also discussed,reflecting on how they revolutionized clinical management.Circulating tumor DNA has emerged as a promising tool for detecting minimal residual disease,prognosis,and therapeutic monitoring,solidifying its role in precision oncology.This review emphasized the importance of technological and therapeutic advancements in improving clinical outcomes and personalizing CRC treatment.

Neoadjuvant chemotherapy with capecitabine combined with oxaliplatin for mid-low locally advanced rectal cancer with negative mesorectal fascia:Long-term outcomes of a prospective trial(PKUCH-R03 trial)

Objective:To evaluate the safety and efficacy of neoadjuvant chemotherapy(NCT)in mid-low locally advanced rectal cancer with negative mesorectal fascia(MRF).Methods:This prospective,single-arm phaseⅡtrial was designed and conducted at Peking University Cancer Hospital.The patients who provided consent received 3 months of NCT(capecitabine and oxaliplatin,CapOX)followed by total mesorectal excision(TME).The primary endpoint was the rate of pathological complete response(pCR).Results:From January 2019 through December 2021,a total of 53 patients were enrolled,7.5%of whom experienced grade 3-4 adverse events during NCT.The pCR rate was 17.0%for the entire cohort,and the overall rate of postoperative complications was 37.7%(1.9%of gradeⅢa patients).The 3-year disease-free survival rate was 91.4%,and 23.5%(12/51)of the patients suffered from major low anterior resection syndrome(LARS).Postoperative complications were independently associated with major LARS.Conclusions:For patients with mid-low rectal cancer with negative MRF,3 months of NCT were found to yield a favorable tumor response with acceptable toxicity.With fair long-term survival,the NCT regimen could be associated with low rates of perioperative complications as well as acceptable anal function.

Preoperative prediction of perineural invasion of rectal cancer based on a magnetic resonance imaging radiomics model:A dual-center study

BACKGROUND Perineural invasion(PNI)has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer(RC).Preoperative prediction of PNI status is helpful for individualized treatment of RC.Recently,several radiomics studies have been used to predict the PNI status in RC,demonstrating a good predictive effect,but the results lacked generalizability.The preoperative prediction of PNI status is still challenging and needs further study.AIM To establish and validate an optimal radiomics model for predicting PNI status preoperatively in RC patients.METHODS This retrospective study enrolled 244 postoperative patients with pathologically confirmed RC from two independent centers.The patients underwent preoperative high-resolution magnetic resonance imaging(MRI)between May 2019 and August 2022.Quantitative radiomics features were extracted and selected from oblique axial T2-weighted imaging(T2WI)and contrast-enhanced T1WI(T1CE)sequences.The radiomics signatures were constructed using logistic regression analysis and the predictive potential of various sequences was compared(T2WI,T1CE and T2WI+T1CE fusion sequences).A clinical-radiomics(CR)model was established by combining the radiomics features and clinical risk factors.The internal and external validation groups were used to validate the proposed models.The area under the receiver operating characteristic curve(AUC),DeLong test,net reclassification improvement(NRI),integrated discrimination improvement(IDI),calibration curve,and decision curve analysis(DCA)were used to evaluate the model performance.RESULTS Among the radiomics models,the T2WI+T1CE fusion sequences model showed the best predictive performance,in the training and internal validation groups,the AUCs of the fusion sequence model were 0.839[95%confidence interval(CI):0.757-0.921]and 0.787(95%CI:0.650-0.923),which were higher than those of the T2WI and T1CE sequence models.The CR model constructed by combining clinical risk factors had the best predictive performance.In the training and internal and external validation groups,the AUCs of the CR model were 0.889(95%CI:0.824-0.954),0.889(95%CI:0.803-0.976)and 0.894(95%CI:0.814-0.974).Delong test,NRI,and IDI showed that the CR model had significant differences from other models(P<0.05).Calibration curves demonstrated good agreement,and DCA revealed significant benefits of the CR model.CONCLUSION The CR model based on preoperative MRI radiomics features and clinical risk factors can preoperatively predict the PNI status of RC noninvasively,which facilitates individualized treatment of RC patients.

Clinical efficacy and pathological outcomes of transanal endoscopic intersphincteric resection for low rectal cancer

BACKGROUND Transanal endoscopic intersphincteric resection(ISR)surgery currently lacks sufficient clinical research and reporting.AIM To investigate the clinical effectiveness of transanal endoscopic ISR,in order to promote the clinical application and development of this technique.METHODS This study utilized a retrospective case series design.Clinical and pathological data of patients with lower rectal cancer who underwent transanal endoscopic ISR at the First Affiliated Hospital of Xiamen University between May 2018 and May 2023 were included.All patients underwent transanal endoscopic ISR as the surgical approach.We conducted this study to determine the perioperative recovery status,postoperative complications,and pathological specimen charac-teristics of this group of patients.RESULTS This study included 45 eligible patients,with no perioperative mortalities.The overall incidence of early complications was 22.22%,with a rate of 4.44%for Clavien-Dindo grade≥III events.Two patients(4.4%)developed anastomotic leakage after surgery,including one case of grade A and one case of grade B.Postoperative pathological examination confirmed negative circumferential resection margins and distal resection margins in all patients.The mean distance between the tumor lower margin and distal resection margin was found to be 2.30±0.62 cm.The transanal endoscopic ISR procedure consistently yielded high quality pathological specimens.CONCLUSION Transanal endoscopic ISR is safe,feasible,and provides a clear anatomical view.It is associated with a low incidence of postoperative complications and favorable pathological outcomes,making it worth further research and application.

Correlation between dose-volume parameters and rectal bleeding after 12 fractions of carbon ion radiotherapy for prostate cancer

BACKGROUND Carbon ion radiotherapy(CIRT)is currently used to treat prostate cancer.Rectal bleeding is a major cause of toxicity even with CIRT.However,to date,a correlation between the dose and volume parameters of the 12 fractions of CIRT for prostate cancer and rectal bleeding has not been shown.Similarly,the clinical risk factors for rectal bleeding were absent after 12 fractions of CIRT.AIM To identify the risk factors for rectal bleeding in 12 fractions of CIRT for prostate cancer.METHODS Among 259 patients who received 51.6 Gy[relative biological effectiveness(RBE)],in 12 fractions of CIRT,15 had grade 1(5.8%)and nine had grade 2 rectal bleeding(3.5%).The dose-volume parameters included the volume(cc)of the rectum irradiated with at least x Gy(RBE)(Vx)and the minimum dose in the most irradiated x cc normal rectal volume(Dx).RESULTS The mean values of D6cc,D2cc,V10 Gy(RBE),V20 Gy(RBE),V30 Gy(RBE),and V40 Gy(RBE)were significantly higher in the patients with rectal bleeding than in those without.The cutoff values were D6cc=34.34 Gy(RBE),D2cc=46.46 Gy(RBE),V10 Gy(RBE)=9.85 cc,V20 Gy(RBE)=7.00 cc,V30 Gy(RBE)=6.91 cc,and V40 Gy(RBE)=4.26 cc.The D2cc,V10 Gy(RBE),and V20 Gy(RBE)cutoff values were significant predictors of grade 2 rectal bleeding.CONCLUSION The above dose-volume parameters may serve as guidelines for preventing rectal bleeding after 12 fractions of CIRT for prostate cancer.

Feasibility and limitations of combined treatment for lateral pelvic lymph node metastases in rectal cancer

Colorectal cancer ranks among the most commonly diagnosed cancers globally,and is associated with a high rate of pelvic recurrence after surgery.In efforts to mitigate recurrence,pelvic lymph node dissection(PLND)is commonly advocated as an adjunct to radical surgery.Neoadjuvant chemoradiotherapy(NACRT)is a therapeutic approach employed in managing locally advanced rectal cancer,and has been found to increase the survival rates.Chua et al have proposed a combination of NACRT with selective PLND for addressing lateral pelvic lymph node metastases in rectal cancer patients,with the aim of reducing recurrence and improving survival outcomes.Nevertheless,certain studies have indicated that the addition of PLND to NACRT and total mesorectal excision did not yield a significant reduction in local recurrence rates or improvement in survival.Consequently,meticulous patient selection and perioperative chemotherapy may prove indispensable in ensuring the efficacy of PLND.

Construction of a nomogram model to predict technical difficulty in performing laparoscopic sphincter-preserving radical resection for rectal cancer

BACKGROUND Colorectal surgeons are well aware that performing surgery for rectal cancer becomes more challenging in obese patients with narrow and deep pelvic cavities.Therefore,it is essential for colorectal surgeons to have a comprehensive understanding of pelvic structure prior to surgery and anticipate potential surgical difficulties.AIM To evaluate predictive parameters for technical challenges encountered during laparoscopic radical sphincter-preserving surgery for rectal cancer.METHODS We retrospectively gathered data from 162 consecutive patients who underwent laparoscopic radical sphincterpreserving surgery for rectal cancer.Three-dimensional reconstruction of pelvic bone and soft tissue parameters was conducted using computed tomography(CT)scans.Operative difficulty was categorized as either high or low,and multivariate logistic regression analysis was employed to identify predictors of operative difficulty,ultimately creating a nomogram.RESULTS Out of 162 patients,21(13.0%)were classified in the high surgical difficulty group,while 141(87.0%)were in the low surgical difficulty group.Multivariate logistic regression analysis showed that the surgical approach using laparoscopic intersphincteric dissection,intraoperative preventive ostomy,and the sacrococcygeal distance were independent risk factors for highly difficult laparoscopic radical sphincter-sparing surgery for rectal cancer(P<0.05).Conversely,the anterior-posterior diameter of pelvic inlet/sacrococcygeal distance was identified as a protective factor(P<0.05).A nomogram was subsequently constructed,demonstrating good predictive accuracy(C-index=0.834).CONCLUSION The surgical approach,intraoperative preventive ostomy,the sacrococcygeal distance,and the anterior-posterior diameter of pelvic inlet/sacrococcygeal distance could help to predict the difficulty of laparoscopic radical sphincter-preserving surgery.

Is ypTNM staging a comparable predictor as pTNM staging for survival in non-metastatic rectal cancer after preoperative chemoradiation therapy?

Abstract:Background:The pTNM staging system is widely recognized as the most effective prognostic indicator for cancer.The latest update of this staging system introduced a new pathological staging system(ypTNM)for patients receiving neoadjuvant chemoradiotherapy(NACRT).However,whether the prognostic value of the ypTNM staging system for rectal cancer is similar to that of the pTNM staging system remains unclear.This study was conducted to compare the ypTNM and pTNM staging systems in terms of their prognostic value for patients with nonmetastatic rectal cancer undergoing proctectomy.Material and Methods:This study was conducted at a large teaching hospital.Between January 2014 and December 2022,542 patients with rectal cancer were analyzed(median follow-up period,60 months;range,6–105 months).Of them,258 and 284 were included in the pTNM and ypTNM groups,respectively.Inverse probability of treatment weighting(IPTW)was performed to account for the effects of confounders.Cox proportional-hazards regression was performed for the between-group comparison of overall survival(OS).Results:The crude model revealed that OS was similar between the two groups(p=0.607).After performing IPTW,we found that patients with the same ypTNM-and pTNM-classified stages had similar overall survival(hazard ratio=1.15;95%CI=0.76–1.73;p=0.5074).Conclusions:For patients with rectal cancer who have received preoperative NACRT,the prognostic value of ypTNM staging appears to be similar to that of pTNM staging,mostly because of the downstaging effect of neoadjuvant chemoradiotherapy。

Chemoradiotherapy plus tislelizumab for mismatch repair proficient rectal cancer with supraclavicular lymph node metastasis:A case report

BACKGROUND According to the latest report,colorectal cancer is still one of the most prevalent cancers,with the third highest incidence and mortality worldwide.Treatment of advanced rectal cancer with distant metastases is usually unsatisfactory,especially for mismatch repair proficient(pMMR)rectal cancer,which leads to poor prognosis and recurrence.CASE SUMMARY We report a case of a pMMR rectal adenocarcinoma with metastases of multiple lymph nodes,including the left supraclavicular lymph node,before treatment in a 70-year-old man.He received full courses of chemoradiotherapy(CRT)followed by 4 cycles of programmed death 1 inhibitor Tislelizumab,and a pathologic complete response(pCR)was achieved,and the lesion of the left supraclavicular lymph node also disappeared.CONCLUSION pMMR advanced rectal cancer with preserved intact distant metastatic lymph nodes may benefit from full-course CRT combined with immunotherapy.

Local excision for middle-low rectal cancer after neoadjuvant chemoradiation:A retrospective study from a single tertiary center

BACKGROUND Rectal cancer has become one of the leading malignancies threatening people’s health.For locally advanced rectal cancer(LARC),the comprehensive strategy combining neoadjuvant chemoradiotherapy(NCRT),total mesorectal excision(TME),and adjuvant chemotherapy has emerged as a standard treatment regimen,leading to favorable local control and long-term survival.However,in recent years,an increasing attention has been paid on the exploration of organ preservation strategies,aiming to enhance quality of life while maintaining optimal oncological treatment outcomes.Local excision(LE),compared with low anterior resection(LAR)or abdominal-perineal resection(APR)was introduced dating back to 1970’s.LE has historically been linked to a heightened risk of recurrence compared to TME,potentially due to occult lymph node metastasis and intraluminal recurrence.Recent evidence has demonstrated that LE might be an alternative approach,instead of LAR or APR,in cases with favorable tumor regression after NCRT with potentially better quality of life.Therefore,a retrospective analysis of clinicopathological data from mid-low LARC patients who underwent LE after NCRT was conducted,aiming to evaluate the treatment's efficacy,safety,and oncologic prognosis.AIM To explore the safety,efficacy,and long-term prognosis of LE in patients with mid-low rectal cancer who had a good response to NCRT.METHODS Patients with LE between 2012 to 2021 were retrospectively collected from the rectal cancer database from Gastro-intestinal Ward III in Peking University Cancer Hospital.The clinicopathological features,postoperative complications,and long-term prognosis of these patients were analyzed.The Kaplan-Meier method was used to create cancer-specific survival curve,and the log-rank test was used to compare the differences regarding outcomes.RESULTS A total of 33 patients were included in this study.The median interval between NCRT and surgery was 25.4(range:8.7-164.4)weeks.The median operation time was 57(20.0-137.0)minutes.The initial clinical T staging(cT):9(27.3%)patients were cT2,19(57.6%)patients were cT3,and 5(15.2%)patients were cT4;The initial N staging(cN):8 patients(24.2%)were cN negative,25 patients(75.8%)were cN positive;The initial M stage(cM):2 patients(6.1%)had distant metastasis(ycM1),31(93.9%)patients had no distant metastasis(cM0).The pathological results:18(54.5%)patients were pathological T0 stage(ypT0),6(18.2%)patients were ypT1,7(21.2%)patients were ypT2,and 2(6.1%)patients were ypT3.For 9 cT2 patients,5(5/9,55.6%)had a postoperative pathological result of ypT0.For 19 cT3 patients,11(57.9%)patients were ypT0,and 2(40%)were ypT0 in 5 cT4 patients.The most common complication was chronic perineal pain(71.4%,5/7),followed by bleeding(43%,3/7),stenosis(14.3%,1/7),and fecal incontinence(14.3%,1/7).The median follow-up time was 42.0(4.0-93.5)months.For 31 patients with cM0,the 5-year disease-free survival(DFS)rate,5-year local recurrence-free survival(LRFS)rate,and 5-year overall survival(OS)rate were 88.4%,96.7%,and 92.9%,respectively.There were significant differences between the ycT groups concerning either DFS(P=0.042)or OS(P=0.002)in the Kaplan-Meier analysis.The LRFS curve of ycT≤T1 patients was better than that of ycT≥T2 patients,and the P value was very close to 0.05(P=0.070).The DFS curve of patients with ypT≤T1 was better than that of patients with ypT≥T2,but the P value was not statistically significant(P=0.560).There was a significant difference between the ypT groups concerning OS(P=0.014)in the Kaplan-Meier analysis.The LRFS curve of ypT≤T1 patients was better than that of ypT≥T2 patients,and the P value was very close to 0.05(P=0.070).Two patients with initial cM1 were alive at the last follow-up.CONCLUSION LE for rectal cancer with significant tumor regression after NCRT can obtain better safety,efficiency,and oncological outcome.Minimally invasive or nonsurgical treatment with patient participation in decision-making can be performed for highly selected patients.Further investigation from multiple centers will bring better understanding of potential advantages regarding local resection.

Study on sex differences and potential clinical value of threedimensional computerized tomography pelvimetry in rectal cancer patients

BACKGROUND Laparoscopic rectal cancer radical surgery is a complex procedure affected by various factors.However,the existing literature lacks standardized parameters for the pelvic region and soft tissues,which hampers the establishment of consistent conclusions.AIM To comprehensively assess 16 pelvic and 7 soft tissue parameters through computerized tomography(CT)-based three-dimensional(3D)reconstruction,providing a strong theoretical basis to address challenges in laparoscopic rectal cancer radical surgery.METHODS We analyzed data from 218 patients who underwent radical laparoscopic surgery for rectal cancer,and utilized CT data for 3D pelvic reconstruction.Specific anatomical points were carefully marked and measured using advanced 3D modeling software.To analyze the pelvic and soft tissue parameters,we emp-loyed statistical methods including paired sample t-tests,Wilcoxon rank-sum tests,and correlation analysis.RESULTS The investigation highlighted significant sex disparities in 14 pelvic bone parameters and 3 soft tissue parameters.Males demonstrated larger measurements in pelvic depth and overall curvature,smaller measurements in pelvic width,a larger mesorectal fat area,and a larger anterior-posterior abdominal diameter.By contrast,females exhibited wider pelvises,shallower depth,smaller overall curvature,and an increased amount of subcutaneous fat tissue.However,there were no significant sex differences observed in certain parameters such as sacral curvature height,superior pubococcygeal diameter,rectal area,visceral fat area,waist circumference,and transverse abdominal diameter.CONCLUSION The reconstruction of 3D CT data enabled accurate pelvic measurements,revealing significant sex differences in both pelvic and soft tissue parameters.This study design offer potential in predicting surgical difficulties and creating personalized surgical plans for male rectal cancer patients with a potentially“difficult pelvis”,ultimately improving surgical outcomes.Further research and utilization of these parameters could lead to enhanced surgical methods and patient care in laparoscopic rectal cancer radical surgery.

Parallel pathways:A chronicle of evolution in rectal and breast cancer surgery

In this editorial,we have analyzed the historical evolution of rectal and breast cancer surgery,focusing on the progressive reduction of demolitive approaches and the increasing use of more conservative strategies,accompanied by a growing emphasis on perioperative treatments aimed at enhancing surgical outcomes.All of these changes have been made possible due to an increased awareness and understanding of oncological diseases and improved perioperative treatments.

Therapy for benign rectal anastomotic stricture after surgery for colorectal cancer:A systematic review

Objective:To evaluate various treatment methods for benign rectal anastomotic stricture(AS)following surgery for colorectal cancer.Method:A systematic review of the literature was conducted,focusing on studies that reported outcomes of different treatment modalities for benign AS.The PubMed,Embase,Scopus,China National Knowledge Infrastructure,and Cochrane Library databases were searched from January 2000 to December 2023.The inclusion criteria were studies involving human subjects,published in English,and reporting on therapeutic outcomes for benign AS.Results:A total of 19 papers identified a range of therapeutic strategies,including nonoperative anastomotic dilation,endoscopic balloon dilation(EBD),transanal minimally invasive surgery(TAMIS),selfexpandable metal stents(SEMS),endoscopic incision(EI)and newer techniques such as prostate resection instrumentation.Nonoperative anastomotic dilation can serve as an initial treatment for lower AS.EI demonstrated promise in cases where EBD was ineffective,providing an alternative method for managing AS.TAMIS and SEMS showed higher efficacy in refractory cases,with TAMIS being particularly effective for severe fibrotic or completely closed AS.The use of rigid instrumentation with an electric knife for transanal incisions demonstrated precision but lacked the flexibility needed for complex procedures.Conclusion:While traditional methods such as nonoperative anastomotic dilation and EBD remain firstline treatments for benign AS,advanced techniques such as EI,TAMIS,and SEMS offer promising alternatives,particularly in refractory cases.The choice of treatment should be tailored to individual patient conditions,with consideration for the technical expertise required and the potential for complications.

Non-operative management of rectal cancer: Highlighting the controversies

There remains much ambiguity on what non-operative management(NOM)of rectal cancer truly entails in terms of the methods to be adopted and the best algorithm to follow.This is clearly shown by the discordance between various national and international guidelines on NOM of rectal cancer.The main aim of the NOM strategy is organ preservation and avoiding unnecessary surgical in-tervention,which carries its own risk of morbidity.A highly specific and sensitive surveillance program must be devised to avoid patients undergoing unnecessary surgical interventions.In many studies,NOM,often interchangeably called the Watch and Wait strategy,has been shown as a promising treatment option when undertaken in the appropriate patient population,where a clinical complete res-ponse is achieved.However,there are no clear guidelines on patient selection for NOM along with the optimal method of surveillance.

Magnetic resonance imaging-based lymph node radiomics for predicting the metastasis of evaluable lymph nodes in rectal cancer

BACKGROUND Lymph node(LN)staging in rectal cancer(RC)affects treatment decisions and patient prognosis.For radiologists,the traditional preoperative assessment of LN metastasis(LNM)using magnetic resonance imaging(MRI)poses a challenge.AIM To explore the value of a nomogram model that combines Conventional MRI and radiomics features from the LNs of RC in assessing the preoperative metastasis of evaluable LNs.METHODS In this retrospective study,270 LNs(158 nonmetastatic,112 metastatic)were randomly split into training(n=189)and validation sets(n=81).LNs were classified based on pathology-MRI matching.Conventional MRI features[size,shape,margin,T2-weighted imaging(T2WI)appearance,and CE-T1-weighted imaging(T1WI)enhancement]were evaluated.Three radiomics models used 3D features from T1WI and T2WI images.Additionally,a nomogram model combining conventional MRI and radiomics features was developed.The model used univariate analysis and multivariable logistic regression.Evaluation employed the receiver operating characteristic curve,with DeLong test for comparing diagnostic performance.Nomogram performance was assessed using calibration and decision curve analysis.RESULTS The nomogram model outperformed conventional MRI and single radiomics models in evaluating LNM.In the training set,the nomogram model achieved an area under the curve(AUC)of 0.92,which was significantly higher than the AUCs of 0.82(P<0.001)and 0.89(P<0.001)of the conventional MRI and radiomics models,respectively.In the validation set,the nomogram model achieved an AUC of 0.91,significantly surpassing 0.80(P<0.001)and 0.86(P<0.001),respectively.CONCLUSION The nomogram model showed the best performance in predicting metastasis of evaluable LNs.