Caracterización epidemiológica de pacientes con síndrome posterior a resección anterior baja de recto y aproximación de su relación con aspectos demográficos, patológicos y quirúrgicos, en un centro de referencia en Medellín, entre 2016-2022 / Epidemiological characterization of patients with post-low anterior rectal resection syndrome and approximation of its relationship with demographic, pathological, and surgical aspects, in a referral center in Medellin, between 2016-2022

Introducción. El cáncer colorrectal es uno de los tipos de cáncer más comunes y mortales a nivel mundial. Aunque los avances médicos han mejorado el manejo, la cirugía sigue siendo fundamental. La resección anterior baja (RAB) de recto ha ganado relevancia, a pesar de que puede llevar al síndrome de resección anterior baja de recto (LARS, por sus siglas en inglés), afectando la calidad de vida. Métodos. Estudio de corte transversal con intención analítica en un centro de referencia en Medellín, Colombia. Los pacientes con cáncer de recto sometidos a RAB entre enero de 2016 y diciembre de 2022 completaron el cuestionario LARS para evaluar disfunción intestinal. Se evaluaron factores relacionados con la presencia de LARS por medio de un análisis bivariado. Resultados. De 234 pacientes elegibles, 110 (47 %) respondieron la encuesta, predominantemente mujeres (58,2 %). La edad promedio fue 62 años. Dos tercios de los pacientes recibieron neoadyuvancia y el 69 % requirieron ileostomía. La prevalencia de LARS fue 47,3 %. El 80,9 % llevaban más de 12 meses desde la cirugía o el cierre del estoma. Factores estadísticamente significativos asociados a LARS fueron edad mayor de 65 años (p=0,03), estadío patológico avanzado (p=0,02) y requerimiento de estoma (p=0,03). Conclusiones. El LARS afecta a casi la mitad de los pacientes en diferentes etapas posquirúrgicas. El LARS scorees una herramienta práctica para evaluar la función intestinal en el seguimiento del paciente. La prevalencia y los factores de riesgo identificados contribuyen a la comprensión del impacto de la cirugía conservadora del esfínter en la calidad de vida de los pacientes.

Introduction. Colorectal cancer is one of the most common and deadly types of cancer worldwide, with a high incidence of rectal cancer. Although medical advances have improved management, surgery remains crucial. Low anterior resection of the rectum (LAR) has gained significance, despite its potential to lead to low anterior resection syndrome (LARS), affecting quality of life. Methods. A cross-sectional study with analytical intent was conducted at a referral center in Medellín, Colombia. Patients with rectal cancer who underwent LAR between January 2016 and December 2022 completed the LARS questionnaire to assess intestinal dysfunction. Factors related to the presence of LARS were analyzed using bivariate analysis. Results. Of 234 eligible patients, 110 (47%) responded, predominantly women (58.2%). The average age was 62 years. Two-thirds of patients received neoadjuvant therapy and 69% required ileostomy. The prevalence of LARS was 47.3%. 80.9% had been more than 12 months post-surgery or stoma closure. Statistically significant factors associated with LARS included age over 65 years (p=0.03), advanced pathological stage (p=0.02), and stoma requirement (p=0.03). Conclusions. LARS affects almost half of the patients in various post-surgical stages. The LARS score is a practical tool for assessing intestinal function in patient follow-up. The prevalence and risk factors identified contribute to the understanding of the impact of sphincter-conserving surgery on patients' quality of life.

Significance and techniques of pelvic floor reconstruction in laparoscopic low anterior resection for rectal cancer / 国际外科学杂志

The residual pelvic floor cavity formed by laparoscopic low anterior resection for rectal cancer can result in some complications, such as spread of pelvic infection following anastomotic leakage, adhesive intestinal obstruction, and may increase the probability of radiation intestinal injury in case of postoperative radiotherapy. Reconstructing the pelvic floor can prevent the small intestine from entering the residual cavity, reduce the risk of intestinal obstruction and radiation induced intestinal injury; prevent or reduce the occurrence and severity of anastomotic leakage. Reconstructing the pelvic floor can also improve the anal function after low anterior resection to a certain extent and enhance the quality of life of patients. Direct suturing of the pelvic floor peritoneum and pedicled greater omentum flap graft transplantation are currently two commonly used pelvic floor reconstruction methods, which are relatively simple to operate, easy to promote, and worthy of routine application.

Precision diagnosis and standardized treatment of mid-low rectal cancer / 中华消化外科杂志

Colorectal cancer is a major digestive disease in China, with mid-low rectal cancer as the predominant cause. Over the years, Chinese colorectal surgery has made considerable strides, attaining certain successes in clinical diagnosis and treatment, scientific research, and data platform construction. Nevertheless, there is still room for improvement in terms of the accuracy of diagnosis and standardization of treatment. Furthermore, immune checkpoint therapy represented by programmed death-1 have demonstrated initial efficacy in the treatment of mid-low rectal cancer. Further research is required to better understand the relationship and role between immune checkpoint inhibitors and traditional radiotherapy and chemotherapy, and to apply them to precise clinical practice. The authors elaborate on current status of diagnosis and treatment for mid-low rectal cancer in China, in order to provide references for its precission diagnosis and standardized treatment.

Effect and safety of preoperative short-course radiotherapy combined with neoadjuvant chemotherapy for elderly patients with locally advanced rectal cancer / 中华老年医学杂志

Objective:To assess the impact of preoperative short-course radiotherapy combined with neoadjuvant chemotherapy on elderly patients with locally advanced rectal cancer after a 2-year follow-up.Methods:In this retrospective cohort study, we included 446 consecutive cases of elderly patients diagnosed and treated for locally advanced rectal cancer(stage Ⅱ-Ⅲ with T3-T4 and/or positive regional lymph nodes)at the First People's Hospital of Shangqiu city from January 2012 to December 2019.The patients were divided into two groups based on the treatment method: an observation group(107 cases)and a control group(339 cases).The patients in the observation group underwent preoperative short-course radiotherapy combined with neoadjuvant chemotherapy.The regimen included short-term radiotherapy(25 Gy over 1 week in 5 fractions)followed by 4 courses of chemotherapy(CAPOX regimen).On the other hand, the control group received concurrent radiotherapy and chemotherapy.The regimen involved 50 Gy over 5 weeks in 25 fractions and concurrent capecitabine chemotherapy.Afterward, total rectal mesentery resection was performed, and postoperatively, 2 and 6 courses of CAPOX chemotherapy were continued.Follow-up was conducted until 31 December 2021, with the primary observation being the disease-free survival(DFS)of patients in both groups.Secondary observations included overall survival(OS)time, lesion progression-free survival(PFS)time, local recurrence rate, and the rate of acute toxicity events.Cox regression analyses were conducted to compare the factors influencing DFS.Results:Among the 446 patients, 303(67.9%)were male and 143(32.1%)were female.The patients in the observation group were found to be younger and had a higher proportion of Eastern Collaborative Oncology Group(ECOG)physical status score 0 compared to the control group(both P<0.05).Additionally, the two groups differed significantly in terms of MRI T stage, N stage, distance from the external anal verge, rectal mesorectal fascial infiltration, pathological stage, and chemotherapy-to-surgery time interval(all P<0.05).Throughout a mean follow-up period of(20.7±3.5)months, there were 76 deaths, 89 distant metastases, and 32 local recurrences.The results of Kaplan-Meier survival analysis revealed that the observation group had a higher disease-free survival(DFS)rate at 2 years of follow-up compared to the control group[73.8%(79/107) vs.68.1%(231/339), Log-rank χ2=2.676, P=0.041].Additionally, the median DFS time was longer in the observation group[19(12, 22)months]compared to the control group[16(11, 19)months]( Z=2.774, P=0.038).Furthermore, the observation group exhibited a significantly longer OS time[26(21, 33)months]compared to the control group[22(18, 14)months]( Z=2.879, P=0.032).However, the median PFS time was similar in both groups[20(14, 25)months vs.16(12, 21)months]( Z=1.545, P=0.123).The incidence of distant metastasis was 18.7%(20/107)in the observation group and 20.4%(69/339)in the control group(Log-rank χ2=0.341, P=0.708), indicating no significant difference.Similarly, there was no significant difference in the risk of local recurrence between the observation group[9.3%(10/107)]and the control group[6.5%(22/339)](Log-rank χ2=0.996, P=0.318).In terms of adverse reactions, there was no statistically significant difference in the incidence of grade≥3 acute toxic reactions between the two groups[19.6%(21/107) vs.12.1%(41/339), Log-rank χ2=1.661, P=0.148].A multifactorial Cox regression analysis revealed that age( HR=0.586, P=0.005), ECOG score( HR=0.721, P=0.028), MRI T-stage( HR=0.605, P=0.008), rectal mesenteric fascial infiltration( HR=1.649, P=0.012), and distance from the external anal verge( HR=0.638, P=0.041)were associated with DFS. Conclusions:The findings indicate that the combination of preoperative short-course radiotherapy and neoadjuvant chemotherapy in elderly patients with locally advanced rectal cancer demonstrates favorable short-term effectiveness and safety.This approach shows promise in improving outcomes for elderly patients with locally advanced rectal cancer.

Clinical application of ileostomy with type B suture / 中华普通外科杂志

Objective:To evaluate safety and efficacy of B-type suture method ileostomy.Methods:Clinical data from 204 patients undergoing laparoscopic low anterior resection combined with protective ileostomy was analysed. Patients were divided into B-type suture ileostomy group ( n=67) and traditional ileostomy group ( n=137). Results:compared with traditional ileostomy group, B-type suture ileostomy group showed statistically significant differences in total operation time [(164±26) min vs. (172±24) min, t=2.229, P=0.027], ileostomy time [(12.7±2.3) min vs. (14.8±2.2) min, t=-6.565, P<0.001], blood loss [(57±20) ml vs. (69±31) ml, t=-2.797, P=0.006], postoperative hospital stay [(10.2±1.9) d vs. (11.8±2.3) d, t=-4.851, P<0.001], specimen incision infection rate (0 vs. 5.1%, P=0.047), postoperative body pain [82 (79-84) vs. 78 (76-80), Z=-5.805, P<0.001], and ileostomy incorporation time [(46±11) min vs. (51±12) min, t=-2.540, P=0.012]. Conclusion:B-type suture ileostomy for prophylactic ileostomy in laparoscopic low anterior resection for rectal cancer is safe and feasible.

Efficacy observation of low-molecular-weight heparin calcium in preventing lower limb deep vein thrombosis after rectal cancer surgery / 肿瘤研究与临床

Objective:To explore the effect of low-molecular-weight heparin calcium in preventing lower limb deep vein thrombosis after rectal cancer surgery.Methods:A retrospective case-control study was conducted. The clinical data of 30 rectal cancer patients with postoperative subcutaneous injection of low-molecular-weight heparin calcium in Beijing Hepingli Hospital from February 2018 to February 2022 were retrospectively analyzed, and 30 patients wearing antithrombotic elastic socks during the same period were selected as controls. In the antithrombotic elastic socks group, the appropriate thrombotic elastic socks were selected according to the actual situation of the patients after operation. Low-molecular-weight heparin calcium group was given subcutaneous injection of low-molecular-weight heparin calcium on the 2nd day after operation. The indexes of coagulation function, situation of postoperative lower limb deep vein thrombosis and perioperative indexes were analyzed.Results:The age of patients in the low-molecular-weight heparin calcium group was (62±12) years old, with 17 women and 13 men. The age of patients in the antithrombotic elastic socks group was (63±1) years old, with 18 women and 12 men. Before prevention, there were no significant differences in platelet count (Plt), activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), fibrinogen (FIB), D-dimer (D-D) levels between the two groups (all P > 0.05). After prevention, the FIB and D-D levels of patients in the low-molecular-weight heparin calcium group [(3.3±0.7) g/L and (341±30) μg/L] were lower than those in the antithrombotic elastic socks group [(4.9±0.6) g/L and (428±40) μg/L] ( t values were 9.51 and 9.61, both P < 0.05), but there were no significant differences in Plt, APTT, TT and PT between the two groups (all P > 0.05). The rate of lower limb deep vein thrombosis in the low-molecular-weight heparin calcium group was lower than that in the antithrombotic elastic socks group [6.67% (2/30) vs. 26.67% (8/30), χ2 = 4.32, P < 0.05]. The drainage flow of anterior sacral drainage tube in the two groups decreased gradually on the 1st, 2nd, 3rd and 4th day after surgery, but there were no significant differences between the two groups (all P > 0.05). The thrombosis time of patients in the low-molecular-weight heparin calcium group was longer than that in the antithrombotic elastic socks group [(84±9) h vs. (73±10) h, t = 4.81, P < 0.05], but there were no significant differences between the two groups in the intraoperative bleeding amount, operation time and postoperative hospital stay (all P > 0.05). Conclusions:Compared with antithrombotic elastic socks, low-molecular-weight heparin calcium is more effective and safer in the prevention of lower limb deep vein thrombosis after rectal cancer surgery.

Imaging research progress on complete pathological remission after neoadjuvant therapy for rectal cancer / 中国医师杂志

Rectal cancer is a common malignant tumor in China, with a high mortality rate ranking fifth. Neoadjuvant therapy for rectal cancer can improve patient prognosis and even achieve pathological complete remission (pCR) in some patients, thereby avoiding complications and functional damage caused by radical surgery. Therefore, how to accurately evaluate pCR before surgery is currently a research hotspot. In recent years, new imaging technologies such as endorectal ultrasound, magnetic resonance imaging (MRI), and positron emission computed tomography (PET-CT) have developed rapidly, and imaging evaluation of pCR after neoadjuvant therapy for rectal cancer has achieved good results. This article provides a review of this field, aiming to provide a basis for personalized treatment of rectal cancer patients.

Multi-Parameters Derived from Dual-Layer Spectral-Detector CT in Evaluating the Pathological Tumor Staging of Rectal Adenocarcinoma / 中国医学影像学杂志

Purpose To explore the value of dual-layer spectral detector CT(DLSCT)in evaluating preoperative tumor staging in rectal adenocarcinoma(RA).Materials and Methods A total of 78 patients with pathologically confirmed RA in Guangdong Provincial Hospital of Chinese Medicine from May 2021 to March 2022 were involved in this retrospective study.All the patients underwent plain and dual-phase contrast-enhanced scans by DLSCT within one week before surgery.Taking pathological results as the golden standard,the accuracy rates of tumor staging were calculated and compared between the multiple-parameter maps derived from DLSCT and 120 kVp polyenergetic image.The effective atomic number(Z-eff)from plain scan,iodine concentration(IC)from arterial phase(AP)and venous phase(VP)were measured.The normalized iodine concentration(NIC)in AP and VP were calculated.The differences of Z-eff,NICAP and NICVP were compared among the pT1-2,pT3 and pT4 groups.The correlation between the pT stages and above values was assessed and the diagnostic efficiencies were analyzed.Results The overall accuracy rate(88.46%vs.67.95%;χ2=9.628,P=0.002),the pT1-2 staging accuracy rate(80.00%vs.40.00%;χ2=6.667,P=0.01),and the pT3 staging accuracy rate(88.10%vs.69.05%;χ2=4.525,P=0.033)of multiple-parameter maps derived from DLSCT were significantly higher than those of 120 kVp polyenergetic image,respectively.The Z-eff,NICAP and NICVP were significantly different among pT stage groups(F=6.456,11.029,12.698,all P<0.05)and exhibited a positive correlation with pT stages(r=0.371,0.367,0.363,all P<0.01).The areas under the curve of Z-eff,NICAP and NICVP to assess pT3-4 staging RA were 0.77,0.71 and 0.74,respectively.Conclusion The multiple-parameter maps derived from DLSCT can significantly improve the diagnostic accuracy of preoperative tumor staging of RA.Z-eff from plain scan and NIC from dual-phase helps differentiate pT1-2 from pT3-4 staging RA.

Progress of Multi-Parameter Magnetic Resonance Imaging in Evaluating the Efficacy of Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer / 中国医学影像学杂志

Neoadjuvant chemoradiotherapy is a part of the current standard treatment mode for locally advanced rectal cancer,which enables a certain proportion of patients to achieve complete tumor response,improving the surgical resection rate and anal retention rate,and then prolonging the disease-free survival period of patients.MRI is the preferred imaging examination to evaluate the efficacy of neoadjuvant therapy.With the development of functional MRI,quantitative parameters derived from different imaging principles can provide more biological information about tumors,improving the clinical application value of MRI.Multi-parameter MRI combining conventional MRI sequences and functional sequences can more comprehensively evaluate the efficacy of neoadjuvant therapy,which is conducive to developing individualized treatment plans for patients in clinical practice and realize precision medicine.

Value of dual-layer detector spectral CT quantitative parameters in evaluating treatment response of neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer / 中华放射学杂志

Objective:To explore the value of dual-layer detector spectral CT quantitative parameters in evaluating the treatment response of neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).Methods:The study was a cross-sectional study. From May 2021 to March 2023, a total of 52 patients with LARC who received complete nCRT and were pathologically confirmed rectal adenocarcinoma at the Guangdong Province Hospital of Traditional Chinese Medicine were retrospectively enrolled. Each patient underwent spectral CT examination before and after nCRT, including plain scan, arterial phase (AP), and venous phase (VP) scans. According to the tumor regression grade, the patients were divided into the good response ( n=20) and the poor response group ( n=32). Measurements of the primary tumor′s spectral CT parameters, including effective atomic number (Z eff) at plain scan, iodine concentration (IC), CT values of 40 keV and 100 keV virtual monochromatic image (VMI) at dual-enhanced phases, were taken before and after nCRT. Additionally, the normalized iodine concentration (NIC), spectral curve slope (λHU), and the change rate of the above parameters before and after nCRT were calculated. The independent sample t-test or Mann-Whitney U test was used to compare the differences between the two groups. The receiver operating characteristic (ROC) curve was used to assess the efficacy of various metrics in evaluating the tumor treatment response of nCRT. A binary logistic regression analysis of combined parameter results was performed for the parameters with the areas under curve (AUC)>0.75, and the AUC of the combined parameter was evaluated. Results:There were significant differences in NIC AP and λHU VP before nCRT, NIC VP and λHU VP after nCRT, and the change rates of Z eff, NIC AP, NIC VP and λHU AP between the good response group and the poor response group ( P<0.05). The remaining parameters showed no statistically significant difference ( P>0.05). The ROC curve results showed that the AUCs of the above 8 parameters for evaluating tumor treatment response of nCRT were 0.702, 0.655, 0.695, 0.769, 0.738, 0.807, 0.791, and 0.677, respectively. The AUC of the combined model of the three parameters with AUC>0.75 (λHU VP after nCRT, the change rate of NIC AP and NIC VP) was 0.869, with 80.0% sensitivity and 84.4% specificity. Conclusion:The quantitative parameters derived from spectral CT may provide new markers for evaluating the response to nCRT treatment in patients with LARC. The multi-parameter combined model can improve diagnostic efficacy.

Predicting the efficacy of neoadjuvant chemoradiotherapy for locally advanced rectal cancer based on lipid metabolism-related genes / 中华放射肿瘤学杂志

Objective:To investigate the value of lipid metabolism-related genes (LMRG) for predicting the efficacy of neoadjuvant chemoradiotherapy in locally advanced rectal cancer (LARC).Methods:GSE46862, a genome-wide expression data of LARC treated with neoadjuvant radiotherapy, was obtained from the Gene Expression Database, and differential expression analysis was performed to obtain differentially expressed genes. The LMRG were collected from the MSigDB database and intersected with differentially expressed genes to obtain differentially expressed LMRG. Candidate LMRG were identified based on three machine learning algorithms including least absolute shrinkage and selection operator (LASSO), support vector machine - recursive feature elimination (SVM-RFE), and random forest (RF). Functional enrichment analysis was performed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to obtain potential function and involved pathways. The accuracy of the candidate LMRG in predicting the efficacy of neoadjuvant chemoradiotherapy for LARC was assessed using receiver operating characteristic (ROC) curve analysis.Results:A total of eight candidate LMRG ( ALOX5AP, FADS2, GALC, PLA2G12A, AGPAT1, AACS, DGKG, ACSBG2) were screened which were mainly involved in biological processes related to lipid metabolism and were involved in the regulation of several important lipid metabolism-related signaling pathways. In addition, these eight candidate LMRG possessed high area under the ROC curve (AUC) for predicting the efficacy of neoadjuvant chemoradiotherapy for LARC. Conclusion:The eight LMRG identified based on three machine learning algorithms had high accuracy in predicting the efficacy of neoadjuvant chemoradiotherapy for LARC, providing clues to identify molecular markers and potential therapeutic targets for preoperative neoadjuvant radiotherapy evaluation of LARC.

Analysis of dose-related factors in small intestine exposure to preoperative radiotherapy for rectal cancer / 中华放射肿瘤学杂志

Objective:To analyze the related factors affecting the dose to the small intestine exposure to preoperative radiotherapy for rectal cancer, aiming to provide reference for alleviating the adverse reactions of radiotherapy for rectal cancer.Methods:Medical record data and radiotherapy plan information of 138 rectal cancer patients who received intensity-modulated arc radiotherapy at Sun Yat-sen University Cancer Center from May 2021 to February 2023 were retrospectively analyzed. Tumor staging, tumor location, gender, age, planned bladder volume, body mass index (BMI), and small intestine irradiation dose volume were subject to Spearman correlation analysis. Further grouping and comparison were conducted based on the correlation results. Independent sample non parametric tests were used for inter group comparison.Results:The main factors related to the small intestine irradiation dose volume were tumor location, gender, planned bladder volume, and BMI. Tumor location was weakly correlated with the small intestine V 5 Gy-V 45 Gy. Gender was weakly correlated with the small intestine V 30 Gy-V 45 Gy. Planned bladder volume was weakly negatively correlated with the small intestine V 20 Gy-V 45 Gy. BMI was weakly negatively correlated with the small intestine V 10 Gy-V 45 Gy. Grouping comparison analysis showed that the small intestine V 5 Gy-V 45 Gy of rectal cancer patients in the low position group was significantly smaller than those in the middle and high position groups (both P<0.05), and there was no significant difference between the middle and high position groups ( P>0.05). Female rectal cancer patients had higher V 30 Gy-V 45 Gy levels than male counterparts ( P<0.05). The small intestine V 20 Gy and V 25 Gy levels in the planned bladder volume <200 ml group were significantly higher than those in the 200-400 ml and >400 ml groups (all P<0.05), whereas there was no difference between the 200-400 ml and >400 ml groups ( P>0.05). The small intestine V 30 Gy-V 45 Gy levels in the 200-400 ml group were significantly lower than those in the <200 ml group, but higher than those in the >400 ml group, and the differences were statistically significant (all P<0.05). Regarding BMI comparison among groups, the small intestine V 15 Gy-V 45 Gy in the low body weight group was significantly higher than those in the other three groups (all P<0.05). There were no significant differences among the normal, overweight, and obese groups (all P>0.05). Conclusion:In preoperative radiotherapy for rectal cancer, more attention should be paid to the dose to the small intestine in patients with middle and high position rectal cancer, female patients, and patients with low body weight.

Restaging magnetic resonance imaging of the rectum after neoadjuvant therapy: a practical guide / Ressonância magnética do reto no reestadiamento após terapia neoadjuvante: um guia prático

Abstract Colorectal cancer is the third most common cancer and the second leading cause of cancer-related death. Rectal cancer accounts for approximately one-third of new colorectal cancer cases, with adenocarcinoma as the predominant subtype. Despite an overall decline in colorectal cancer incidence and mortality, due to advancements in screening, early diagnosis, and treatment options, there is a concerning increase in incidence rates among young patients. Recent significant advances in managing locally advanced rectal cancer, such as the establishment of different surgical approaches, neoadjuvant treatment using different protocols for high-risk cases, and the adoption of organ-preservation strategies, have increased the importance of the role played by radiologists in locoregional assessment on magnetic resonance imaging at baseline, at restaging, and during active surveillance of patients with rectal cancer. In this article, we review the role of restaging rectal magnetic resonance imaging after neoadjuvant therapy, providing radiologists with a practical, step-by-step guide for assessing treatment response.

Resumo O câncer colorretal é o terceiro câncer mais comum e a segunda principal causa de morte relacionada ao câncer. O câncer retal representa aproximadamente um terço dos novos casos de câncer colorretal, sendo o adenocarcinoma o subtipo predominante. Apesar de uma diminuição geral na incidência e mortalidade, impulsionada por avanços na prevenção do câncer, diagnóstico precoce e opções de tratamento aprimoradas, há uma preocupante elevação nas taxas entre os pacientes jovens. Avanços recentes significativos no manejo do câncer retal localmente avançado, como abordagens cirúrgicas, o uso de diferentes protocolos de tratamento neoadjuvante para casos de alto risco e a adoção de estratégias de preservação de órgãos, aumentaram o papel dos radiologistas na avaliação locorregional por meio da ressonância magnética na avaliação inicial, reestadiamento e vigilância ativa de pacientes com câncer retal. Este manuscrito tem como objetivo revisar o papel da ressonância magnética retal no reestadiamento após terapia neoadjuvante, fornecendo aos radiologistas um guia prático para revisar exames nesse contexto.

Primary Anorectal Melanoma: Case Report and Review of a Rare Neoplasm

Primary anorectal melanoma is a rare malignant melanocytic neoplasm; its principal manifestation is rectal bleeding. It has an ominous prognosis with a five-year survival rate of 10%. The case of a 56-year-old woman with rectal bleeding and the sensation of a rectal mass is presented. A polypoid lesion, resected transanally, was documented in the distal rectum during the colonoscopy. The histological study confirmed a primary anorectal melanoma.

El melanoma anorrectal primario es una neoplasia melanocítica maligna poco frecuente, su principal manifestación es el sangrado rectal. Tiene un pronóstico ominoso con una tasa de sobrevida del 10% a 5 años. Se presenta el caso de una mujer de 56 años con rectorragia y sensación de masa rectal. Durante la colonoscopia se documentó una lesión polipoide en el recto distal, que se resecó por vía transanal. El estudio histológico confirmó la presencia de un melanoma anorrectal primario.

Progress in imaging evaluation of lateral lymph node metastasis in rectal cancer / 国际肿瘤学杂志

Lateral drainage is an important way for the middle and lower rectum. There are still disputes between Eastern and Western scholars regarding the treatment strategy of lateral lymph node metastasis. It is difficult to diagnose lateral lymph node metastasis by pathologic examination before surgery. MRI is the main method for diagnosis of lateral lymph node metastasis in rectal cancer. The diagnostic criteria for patients before and after neoadjuvant treatment are slightly different. CT, PET/CT and radiomics also have certain advantages in the diagnosis of lateral lymph node metastasis. If necessary, the combination of multiple methods can help in the diagnosis of lateral lymph node metastasis.

Clinical efficacy of radical resection of rectal cancer with different surgical approaches and analysis of influencing factors of postoperative complications: a report of 3 418 cases / 中华消化外科杂志

Objective:To investigate the clinical efficacy of radical resection of rectal cancer with different surgical approaches and influencing factors of postoperative complications.Methods:The retrospective study was conducted. The clinicopathological data of 3 418 patients who underwent radical resection of rectal cancer in the Second Affiliated Hospital of Harbin Medical University from July 2011 to September 2020 were collected. There were 2 060 males and 1 358 females, aged (61±11)years. Patients meeting the requirements of radical resection and surgical indications underwent surgeries choosing from open radical colorectal cancer surgery, laparoscopic radical colorectal cancer surgery, and natural orifice specimen extraction surgery (NOSES). Observation indicators: (1) intraoperative and postoperative conditions of patients undergoing different surgical approaches; (2) comparison of preoperative clinical characteristics in patients undergoing different surgical approaches; (3) comparison of postoperative histopathological characteristics in patients undergoing different surgical approaches; (4) postoperative complications of patients undergoing different surgical approaches; (5) analysis of influencing factors of postoperative complications. Measurement data with normal distribution were represented as Mean± SD. Measurement data with skewed distribution were represented as M(range), and comparisons between groups was analyzed using the Kruskal-Wallis rank test. Comparison of ordinal data was analyzed using the non-parameter rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test. Multivariate analysis was conducted using the Logistic regression model. Results:(1) Intraoperative and postoperative conditions of patients undergoing different surgical approaches. Of the 3 418 patients, 1 978 cases underwent open radical colorectal cancer sur-gery, 1 028 cases underwent laparoscopic radical colorectal cancer surgery and 412 cases underwent NOSES, respectively. The operation time, volume of intraoperative blood loss, cases with permanent stoma, preventive stoma or without fistula, time to postoperative first flatus, time to postoperative liquid food intake, cases transferred to intensive care unit after surgery, duration of postoperative hospital stay were 145(range, 55?460)minutes, 100(range, 30?1 000)mL, 435, 88, 1 455, 72(range, 10?220)hours, 96(range, 16?296)hours, 158, 10(range, 6?60)days, respectively, in patients undergoing open radical colorectal cancer surgery. The above indicators were 175(range, 80?450)minutes, 50(range, 10?800)mL, 172, 112, 744, 48(range, 14?120)hours, 72(range, 38?140)hours, 17, 9(range, 4?40)days, respectively, in patients undergoing laparoscopic radical colorectal cancer surgery and 180(range, 80?400)minutes, 30(range, 5?500)mL, 0, 45, 367, 48 (range, 14?144)hours, 72(range, 15?148)hours, 1, 6(range, 3?30)days, respectively, in patients undergoing NOSES. There were significant differences in the above indicators among the patients undergoing different surgical approaches ( H=291.38, 518.56, χ2=153.82, H=408.86, 282.97, χ2=78.66, H=332.30, P<0.05). (2) Com-parison of preoperative clinical characteristics in patients undergoing different surgical approaches. The gender, age, body mass index, cases with diabetes, cases with hypertension, cases with coronary heart disease, cases with anemia, cases with hypoproteinemia, cases with intestinal obstruction, tumor location, preoperative carcinoembryonic antigen, preoperative CA19-9 showed significant differences among patients undergoing open radical colorectal cancer surgery, laparoscopic radical colorectal cancer surgery and NOSES ( P<0.05). (3) Comparison of postoperative histopathological characteris-tics in patients undergoing different surgical approaches. Tumor histological type, tumor differentiation degree, tumor diameter, number of lymph node detected, nerve invasion, vascular invasion, lymph node invasion, tumor T staging, tumor N staging, tumor M staging, tumor TNM staging showed significant differences among patients undergoing open radical colorectal cancer surgery, laparos-copic radical colorectal cancer surgery and NOSES ( P<0.05). (4) Postoperative complications of patients undergoing different surgical approaches. Cases with postoperative complications as anastomotic leakage, abdominal infection, intestinal obstruction, anastomotic bleeding, incision complications, pulmonary infection, other complications were 52, 21, 309, 8, 130, 51, 59, respectively, in patients undergoing open radical colorectal cancer surgery. The above indicators were 33, 17, 75, 3, 45, 58, 9, respectively, in patients undergoing laparoscopic radical colorectal cancer surgery and 13, 4, 8, 0, 11, 10, 15, respectively, in patients undergoing NOSES. There were significant differences in the intes-tinal obstruction, incision complications, pulmonary infection, other complications among patients undergoing different surgical approaches ( χ2=122.56, 13.33, 20.44, 15.59, P<0.05) and there was no significant difference in the anastomotic leakage, abdominal infection, anastomotic bleeding among patients undergoing different surgical approaches ( χ2=0.96, 2.21, 3.08, P>0.05). (5) Analysis of influencing factors of postoperative complications. ① Analysis of influencing factors of intestinal obstruction in patients with radical resection of rectal cancer. Age as 20?39 years and 40?59 years, surgical approach as laparoscopic radical colorectal cancer surgery and NOSES were independent protective factors of intestinal obstruction in patients with radical resection of rectal cancer ( odds ratio=0.46, 0.59, 0.43, 0.13, 95% confidence interval as 0.21?1.00, 0.36?0.96, 0.33?0.56, 0.06?0.27, P<0.05). ② Analysis of influencing factors of incision complications in patients with radical resection of rectal cancer. Body mass index as 24.0?26.9 kg/m 2, surgical approach as laparoscopic radical colorectal cancer surgery and NOSES were independent protective factors of incision complications in patients with radical resection of rectal cancer ( odds ratio=0.24, 0.63, 0.46, 95% confidence interval as 0.11?0.51, 0.44?0.89, 0.24?0.87, P<0.05). ③ Analysis of influencing factors of pulmonary infection in patients with radical resection of rectal cancer. The surgical approach as laparoscopic radical colorectal cancer surgery was an independent risk factor of pulmonary infection in patients with radical resection of rectal cancer ( odds ratio=2.15, 95% confidence interval as 1.46?3.18, P<0.05), and tumor TNM staging as 0?Ⅰ stage was an independent protective factor ( odds ratio=0.10, 95% confidence interval as 0.01?0.88, P<0.05). ④ Analysis of influencing factors of other complica-tions in patients with radical resection of rectal cancer. Age as 20?39 years, 40?59 years, 60?79 years, body mass index as <18.5 kg/m 2, 18.5?23.9 kg/m 2, 24.0?26.9 kg/m 2, 27.0?29.9 kg/m 2, surgical approach as laparoscopic radical colorectal cancer surgery were independent protective factors of other complications in patients with radical resection of rectal cancer ( odds ratio=0.10, 0.29, 0.37, 0.08, 0.22, 0.35, 0.32, 0.29, 95% confidence interval as 0.01?0.81, 0.13?0.64, 0.17?0.78, 0.02?0.40, 0.09?0.52, 0.15?0.83, 0.12?0.89, 0.14?0.59, P<0.05). Conclusions:Compared to laparoscopic radical colorectal cancer surgery and NOSES, open radical colorectal cancer surgery has wide indication and short operation time, but less perioperative treatment effect. Laparoscopic radical colorectal cancer surgery and NOSES can achieve better surgical result and less postoperative complication when patients meeting surgical indications.

Influencing factors of anastomotic leakage after laparoscopic intersphincter resection for extremely low rectal cancer and construction of nomogram prediction model / 中华消化外科杂志

Objective:To investigate the influencing factors of anastomotic leakage after laparoscopic intersphincter resection (ISR) for extremely low rectal cancer and construction of nomogram prediction model.Methods:The retrospective case-control study was conducted. The clinicopathological data of 812 patients who underwent laparoscopic ISR for extremely low rectal cancer in the Second Affiliated Hospital of Naval Medical University (Shanghai Changzheng Hospital) from February 2012 to February 2022 were collected. There were 459 males and 353 females, aged (51±11)years. Observation indicators: (1) surgical situations; (2) follow-up; (3) influencing factors of postoperative anastomotic leakage; (4) construction and evaluation of nomogram prediction model for postoperative anastomotic leakage. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers. The COX proportional hazard model was used for univariate and multivariate analyses. The R software(3.5.1 version) was used to construct nomogram prediction model. The receiver operating characteristic (ROC) curve was drawn and the area under curve (AUC) was used to evaluate the efficacy of the nomogram prediction model. The Bootstrap method was used for internal verification and to calculate the average consistency index (C-index). Results:(1) Surgical situations. All 812 patients underwent laparoscopic ISR for extremely low rectal cancer, including 388 cases undergoing partial ISR, 218 cases undergoing subtotal ISR and 206 cases undergoing complete ISR. All 812 patients underwent ileal protective ostomy, and there were 306 cases with double anastomosis and 203 cases with left colic artery preserved, respectively. The operation time and volume of intraoperative blood loss of 812 patients was (179±33)minutes and (33±13)mL, respectively. (2) Follow-up. All 812 patients were followed up for (13.5±0.9)months. Of the 812 patients, there were 62 cases with postoperative anastomotic leakage and the healing time of these cases was (33±6)days. (3) Influencing factors of postoperative anastomotic leakage. Results of multivariate analysis showed that male, neoadjuvant chemoradiotherapy, failure of reser-ving left colic artery were independent risk factors of anastomotic leakage after laparoscopic ISR for extremely low rectal cancer ( hazard ratio=5.98, 4.00, 16.26, 95% confidence interval as 1.66-24.12, 1.30-12.42, 3.00-90.89, P<0.05). (4) Construction and evaluation of nomogram prediction model for postoperative anastomotic leakage. According to the results of multivariate analysis, male, neoadju-vant chemoradiotherapy and failure of reserving left colic artery were used to construct the nomogram prediction model for anastomotic leakage after laparoscopic ISR for extremely low rectal cancer, and the score of these indexes in the nomogram prediction model was 50, 49, 93, respectively. The total score of these index corresponded to the incidence rate of anastomotic leakage. Results of ROC curve showed that the AUC of nomogram prediction model of anastomotic leakage after laparoscopic ISR for extremely low rectal cancer was 0.87 (95% confidence interval as 0.80-0.93, P<0.05), with sensi-tivity and specificity 0.96 and 0.60, respectively. Results of internal verification showed that the C-index of nomogram prediction model was 0.87. Conclusion:Male, neoadjuvant chemoradiotherapy, failure of reserving left colic artery are independent risk factors of anastomotic leakage after laparo-scopic ISR for extremely low rectal cancer, and the nomogram prediction model based on these indexes can predict the incidence rate of postoperative anastomotic leakage.

Application and challenge of microsatellite instability detection in colorectal cancer / 中华消化外科杂志

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers. The incidence and mortality of CRC are still rising in China. It is of great importance to explore the molecular mechanisms of the development and progression of CRC. Microsatellites are short tandem repeats that are distributed throughout the genome. Detection of microsatellite instability (MSI) is of great value in the diagnosis and treatment of CRC. MSI detection is an important method for Lynch syndrome screening. For patients with stage Ⅱ CRC, MSI status is an influencing factor for post-operative recurrence and an important reference for adjuvant therapy. For patients with stage Ⅳ CRC, MSI status is an important indicator for screening potential patients suitable for treatment of immune checkpoint inhibitors. However, there are still problems concerning the application of MSI. The detection methods of MSI have not been fully unified. The requirement of MSI detection in CRC patients are universal but not precise. MSI is not a valid predictor for the prognosis of CRC patients, and it could not effectively predict the efficacy of chemotherapy and immunotherapy. Moreover, with the application of other molecular markers, such as programmed death-1, programmed death-ligand 1, tumor mutation burden and immunoscore, the value of MSI in CRC is being challenged and remains to be unveiled with more studies. The authors investigate the problems in MSI detection and application, in order to provide reference for clinical practice.

Technical advantages and oncological efficacy of transanal total mesorectal excision for rectal cancer / 中华消化外科杂志

Total mesorectal excision (TME) is an effective surgical method to reduce the local recurrence of rectal cancer and improve patient prognosis. However, there is debate about which surgical platform to use to achieve the best surgical outcome for TME. The emergence and technological progress of transanal total mesorectal excision (taTME) can solve the problem of difficulty in lower rectal resection and achieve better surgical resection results. Based on relevant literatures and combined with team clinical practice, the authors explore the technical advantages and oncological efficacy of taTME in rectal cancer.

Sphincter preservation operation and comprehensive treatment for ultra-low rectal cancer / 中华消化外科杂志

In the past 20 years, the multidisciplinary treatment model based on evidence-based medicine has significantly increased the rate of sphincter-preservation operation for rectal cancer. How to preserve rectum and anal function, avoid permanent colostomy, and improve post-operative quality of life of patients while ensuring radical resection of tumor, remains to be a key and hot topic in surgical treatment of rectal cancer. Based on literatures and clinical experiences, the authors summarize issues of sphincter preservation operation and comprehensive treatment, including intersphincteric resection, conformal sphincter preservation operation, total neoadjuvant therapy and radioimmunotherapy, for ultra-low rectal cancer, in order to provide reference for the colleagues.