Endoscopic treatment and management of rectal neuroendocrine tumors less than 10 mm in diameter

Rectal neuroendocrine tumors(rNETs)measuring less than 10 mm in diameter are defined as small rNETs.Due to the low risk of distant invasion and metastasis,endoscopic treatments,including modified endoscopic mucosal resection,endoscopic submucosal dissection,and other transanal surgical procedures,are effective.This review article proposes a follow-up plan according to the size and histopathology of the tumor after operation.

Colon and rectal cancer:An emergent public health problem

Colorectal cancer ranks third globally,with a high mortality rate.In the United States,and different countries in Europe,organized population screenings exist and include people between 50 and 74 years of age.These screenings have allowed an early diagnosis and consequently an improvement in health indicators.Colon and rectal cancer(CRC)is a disease of particular interest due to the high global burden associated with it and the role attributed to prevention and early diagnosis in reducing morbidity and mortality.This study is a review of CRC pathology and includes the most recent scientific evidence regarding this pathology,as well as a diagnosis of the epidemiological situation of CRC.Finally,the recommendation from a public health perspective will be discussed in detail taking into account the context and the most current recommendations.

Is lymphatic invasion of microrectal neuroendocrine tumors an incidental event?:A case report

BACKGROUND A rectal neuroendocrine tumor(rNET)is a malignant tumor originating from neuroendocrine cells.Currently,tumor size is the primary basis for assessing tumor risk.CASE SUMMARY This article reports the case of a 46-year-old male patient who underwent a colonoscopy that found a 3 mm rectal polypoid bulge.The pathological examination of a sample collected with biopsy forceps revealed a neuroendocrine tumor.Further endoscopic submucosal dissection rescue therapy was used.The presence of lymphatic vessels indicated that the tumor had infiltrated the negative resection margin.The lesion was located in the distal rectum near the anal canal.Therefore,to ensure the patient’s quality of life,follow-up observation was conducted after full communication with the patient.No tumor recurrence or distant metastasis has been found during the 13-mo follow-up after surgery.CONCLUSION Despite the presence of lymphatic invasion and extremely small diameter rNETs in our case,this phenomenon may not imply a higher risk of distant lymph node and organ metastasis.

Endoscopic mucosal resection with double band ligation versus endoscopic submucosal dissection for small rectal neuroendocrine tumors

BACKGROUND Endoscopic resection remains an effective method for the treatment of small rectal neuroendocrine tumors(NETs)(≤10 mm).Moreover,endoscopic mucosal resection(EMR)with double band ligation(EMR-dB),a simplified modification of EMR with band ligation,is an alternative strategy to remove small rectal NETs.AIM To evaluate the feasibility and safety of EMR-dB for the treatment of small rectal NETs(≤10 mm).METHODS A total of 50 patients with small rectal NETs,without regional lymph node enlargement or distant metastasis confirmed by endoscopic ultrasound,computerized tomography scan,or magnetic resonance imaging,were enrolled in the study from March 2021 to June 2022.These patients were randomly assigned into the EMR-dB(n=25)group or endoscopic submucosal dissection(ESD)group(n=25).The characteristics of the patients and tumors,procedure time,devices cost,complete resection rate,complications,and recurrence outcomes were analyzed.RESULTS There were 25 patients(13 males,12 females;age range 28-68 years old)in the EMR-dB group,and the ESD group contained 25 patients(15 males,10 females;age range 25-70 years old).Both groups had similar lesion sizes(EMR-dB 4.53±1.02 mm,ESD 5.140±1.74 mm;P=0.141)and resected lesion sizes(1.32±0.52 cm vs 1.58±0.84 cm;P=0.269).Furthermore,the histological complete resection and en bloc resection rates were achieved in all patients(100%for each).In addition,there was no significant difference in the complication rate between the two groups.However,the procedure time was significantly shorter and the devices cost was significantly lower in the EMRdB group.Besides,there was no recurrence in both groups during the follow-up period.CONCLUSION The procedure time of EMR-dB was shorter compared with ESD,and both approaches showed a similar curative effect.Taken together,EMR-dB was a feasible and safe option for the treatment of small rectal NETs.

Rectal neuroendocrine tumors:Current advances in management,treatment,and surveillance

Rectal neuroendocrine neoplasms(r-NENs)are considered among the most frequent digestive NENs,together with small bowel NENs.Their incidence has increased over the past few years,and this is probably due to the widespread use of endoscopic screening for colorectal cancer and the advanced endoscopic procedures available nowadays.According to the current European Neuroendocrine Tumor Society(ENETS)guidelines,well-differentiated r-NENs smaller than 10 mm should be endoscopically removed in view of their low risk of local and distant invasion.R-NENs larger than 20 mm are candidates for surgical resection because of their high risk of distant spreading and the involvement of the muscularis propria.There is an area of uncertainty regarding tumors between 10 and 20 mm,in which the metastatic risk is intermediate and the endoscopic treatment can be challenging.Once removed,the indications for surveillance are scarce and poorly codified by international guidelines,therefore in this paper,a possible algorithm is proposed.

Risk factors of lymph node metastasis in rectal neuroendocrine tumors

Objective The aim of this study was to investigate the risk factors of lymph node metastasis in rectal neuroendocrine neoplasms(RNENs).Methods We enrolled 168 patients with RNENs as the research object,and their clinicopathological and survival data were collected.The risk factors affecting lymph node metastasis were analyzed retrospectively,and independent risk factors affecting prognosis were evaluated.Results Analysis showed that age,tumor diameter,tumor function,grade,and T stage were correlated with lymph node metastasis(P<0.05).Multiple logistic regression analysis showed that tumor size,grade,and T stage were independent risk factors for lymph node metastasis in patients with RNENs.Kaplan-Meier analysis showed that the 5-year overall survival(OS)of patients with lymph node metastasis was 40.0%(10/25),and that of patients without lymph node metastasis was 93.0%(133/143).The prognosis of RNENs patients with lymph node metastasis along with patients with large tumor diameter and high grade was poor.Cox multivariate analysis showed that tumor diameter(HR=1.985,P=0.008),grade(HR=3.416,P=0.004),T stage(HR=2.413,P=0.014),and lymph node metastasis(HR=3.119,P=0.000)were independent risk factors affecting the prognosis of patients with RNENs.Conclusion Tumor size,grade,and T stage are the main risk factors for lymph node metastasis and prognosis in patients with RNENs.These risk factors should be fully evaluated before surgery.

Rectal Endometriosis Revealed by a Colonic Tumor Obstruction: A Case Report

Endometriosis is defined as the presence of endometrial tissue that is located outside the uterine cavity, associated with fibrosis and inflammatory reaction. The most common atypical locations are the gastrointestinal tract, urinary tract, lung, as well as abdominal surgical scars. Its diagnosis is still very difficult, especially when it manifests itself as an acute large bowel obstruction. We report the rare case of a 41-year-old patient diagnosed with acute colonic obstruction following a rectal tumor. She had undergone colonostomy even though colonoscopy biopsies were nonspecific, and a computed tomography (CT) scan was requested. It showed an adnexal heterogenous mass, therefore the patient had a laparotomy and a subtotal hysterectomy with bilateral salpingo-oophorectomy and a biopsy of the recto-colonic hinge. Histologic examination revealed a diagnosis of rectal endometriosis. The purpose of this work is to report a rare case of colonic endometriosis responsible for an acute large bowel obstruction.

How useful is rectal endosonography in the staging of rectal cancer?

It is essential in treating rectal cancer to have adequate preoperative imaging,as accurate staging can influence the management strategy,type of resection,and candidacy for neoadjuvant therapy.In the last twenty years,endorectal ultrasound(ERUS) has become the primary method for locoregional staging of rectal cancer.ERUS is the most accurate modality for assessing local depth of invasion of rectal carcinoma into the rectal wall layers(T stage) .Lower accuracy for T2 tumors is commonly reported,which could lead to sonographic overstaging of T3 tumors following preoperative therapy.Unfortunately,ERUS is not as good for predicting nodal metastases as it is for tumor depth,which could be related to the unclear definition of nodal metastases.The use of multiple criteria might improve accuracy.Failure to evaluate nodal status could lead to inadequate surgical resection.ERUS can accurately distinguish early cancers from advanced ones,with a high detection rate of residual carcinoma in the rectal wall.ERUS is also useful for detection of local recurrence at the anastomosis site,which might require fine-needle aspiration of the tissue.Overstaging is more frequent than understaging,mostly due to inflammatory changes.Limitations of ERUS are operator and experiencedependency,limited tolerance of patients,and limited range of depth of the transducer.The ERUS technique requires a learning curve for orientation and identification of images and planes.With sufficient time and effort,quality and accuracy of the ERUS procedure could be improved.

Gastrointestinal neuroendocrine tumors in 2020

Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological,biological,and clinical characteristics that have increased in incidence and prevalence within the last few decades.They contain chromogranin A,synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor.Ki-67 index and mitotic index correlate with cellular proliferation.Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors.Most of the gastrointestinal neuroendocrine tumors are non-functional.World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm.Gastric neuroendocrine tumors arise from enterochromaffin like cells.They are classified into 4 types.Only type I and type II are gastrin dependent.Small intestinal neuroendocrine tumor is the most common small bowel malignancy.More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve.Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs.Duodenal and jejunoileal neuroendocrine tumors are distinct biologically and clinically.Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver.Appendiceal neuroendocrine tumors are generally detected after appendectomy.Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis.Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000.Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy,endoscopic ultrasound,serology of biomarkers,imaging studies and functional somatostatin scans.Various treatment options are available for curative and palliative treatment of gastrointestinal neuroendocrine tumors.

Potential predictive factors for pathologic complete response after the neoadjuvant treatment of rectal adenocarcinoma:a single center experience

Objective:To assess the response rate of patients with rectal adenocarcinoma to neoadjuvant therapy and to identify the predictors of histological regression after neoadjuvant radiotherapy(RT)or concurrent chemoradiotherapy(CCRT).Methods:This study recruited 64 patients.The patients had resectable cancer of the lower and the middle rectum(T3/T4 and/or N+)without distant metastasis and received neoadjuvant RT or CCRT followed by radical surgery with total mesorectal excision(TME)between January 2006 and December 2011.The patients were classified into non-response(NR),partial response(PR),and pathologic complete response(p CR)based on the Dworak tumor regression grading system.Results:The median age of patients was 57 years(ranging from 22 to 85).A total of 24 patients were treated with neoadjuvant CCRT,whereas 40 patients were treated with RT alone.Abdominoperineal resection(APR)was performed on 29 patients(45%).Anterior resection with TME was performed on 34 patients(53%).One patient had local resection.Histologically,12(19%),24(73%),and 28(44%)patients exhibited p CR,PR,and NR,respectively.Univariate analysis revealed that the predictors of tumor regression were as follows:the absence of lymph node involvement from initial imaging(c N0)(P=0.021);normal initial carcinoembryonic antigen(CEA)level(P=0.01);hemoglobin level≥12 g/dl(P=0.009);CCRT(P=0.021);and tumor downstaging in imaging(P=0.001).Multivariate analysis showed that the main predictors of p CR were CT combined with neoadjuvant RT,c N0stage,and tumor regression on imaging.Conclusions:Identifying the predictors of p CR following neoadjuvant therapy aids the selection of responsive patients for nonaggressive surgical treatment and possible surveillance.

SIGNIFICANCE OF CEA AND CA242 IN THE DIAGNOSIS OF COLORECTAL CARCINOMA

Carcinoembryonic antigen (CEA) is frequently used in the diagnosis of the colorectal carcinoma. CA242 is a novel unique tumor-associated antigen characterized by higher tumor specificity and sensitivity for colorectal cancer, as compared with other mucin antigens. In this study, preoperative levels of serum CEA and CA242 were measured in 63 cases of colorectal carcinoma. It was disclosed that the positive rate of CA242 was higher than that of CEA, particularly in patients with colon cancer.The combined determination of CEA and CA242 significantly increased the sensitivity and accuracy in the detection of colorectal cancer as compared with the use of CEA alone (P<0.o1). In patients with advanced disease the positive rate was markedly elevated, especially in patients with liver metastasis. The results indicate that the combined use of CEA and CA242 assays is an useful adjunct diagnostic measure for colorectal carcinoma, and is helpful in the assessment of the stage of the disease as well as in making treatment Plan.

Radical Operation and Everolimus Therapy for Rectal Neuroendocrine Tumor with Liver Metastases: A Case Report with Review of the Literature

Neuroendocrine tumors (NETs) are often misdiagnosed because they can involve any part of the body and have non-specific symptoms. Here, we report a case of a 39-year-old man with rectal neuroendocrine tumor (RNET) and hepatic metastases treated with a combination of radical surgery and Everolimus therapy. The patient complained of abdominal distension, pain, and constipation of one month duration. Enhanced CT scan of the abdomen, colonoscopy and Biopsy findings confirmed the diagnosis of rectal neuroendocrine tumor. As the anatomical structures were clear and the masses seemed to be resectable, we decided to initiate treatment with radical operation and Everolimus therapy. The patient has responded well to the treatment with no evidence of recurrence after 4 years of follow-up. This case is interesting because of the rarity of this neoplasm and its initial misdiagnosis as a giant hepatic carcinoma (hepatoma). It also demonstrates that a combination of curative surgical resection and Everolimus is a good option in a patient with large colorectal neuroendocrine tumors and massive hepatic metastases.

Prostate-specific antigen reduction after capecitabine plus oxaliplatin chemotherapy:A case report

BACKGROUND Prostate cancer(PC)is currently the most common malignant tumor of the genitourinary system in men.Radical prostatectomy(RP)is recommended for the treatment of patients with localized PC.Adjuvant hormonal therapy(AHT)can be administered postoperatively in patients with high-risk or locally advanced PC.Chemotherapy is a vital remedy for castration-resistant prostate cancer(CRPC),and may also benefit patients with PC who have not progressed to CRPC.CASE SUMMARY A 68-year-old male was admitted to our hospital because of urinary irritation and dysuria with increased prostate-specific antigen(PSA)levels.After detailed examination,he was diagnosed with PC and treated with laparoscopic RP on August 3,2020.AHT using androgen deprivation therapy(ADT)was performed postoperatively because of the positive surgical margin,extracapsular extension,and neural invasion but lasted only 6 mo.Unfortunately,he was diagnosed with rectal cancer about half a year after self-cessation of AHT,and was then treated with laparoscopic radical rectal resection and adjuvant chemotherapy using the capecitabine plus oxaliplatin(CapeOx)regimen.During the entire treatment process,the patient's PSA level first declined significantly after treatment of PC with laparoscopic RP and ADT,then rebounded because of self-cessation of ADT,and finally decreased again after CapeOx chemotherapy.CONCLUSION CapeOx chemotherapy can reduce PSA levels in patients with high-risk locally advanced PC,indicating that CapeOx may be an alternative chemotherapy regimen for PC.

Risk factors and clinical outcomes of incomplete endoscopic resection of small rectal neuroendocrine tumors in southern China:a 9-year data analysis

Background:The histologically complete resection(CR)rate of small rectal neuroendocrine tumors(RNETs)is unsatisfactory at the first endoscopy.Risk factors and clinical outcomes associated with incomplete resection(IR)have not been explicitly elucidated.This study aims to explore the relevant factors of IR.Methods:This retrospective study reviewed patients with small RNETs(10mm)in eight centers from January 2013 to December 2021.Clinicopathological characteristics and clinical outcomes were compared between the CR and IR groups,and the polypectomy and advanced treatment groups.Results:Of the 326 patients included,83(25.5%)were diagnosed with IR.Polypectomy(odds ratio[OR]=16.86),a central depression(OR=7.50),and treatment in the early period(OR=2.60)were closely associated with IR.Further analysis revealed that an atypical hyperemic appearance(OR=7.49)and treatment in the early period(OR=2.54)were significantly associated with the inappropriate use of polypectomy(both P<0.05).In addition,a total of 265(81.3%)were followed up with a median follow-up period of 30.9 months.No death,metastasis,or recurrence was found during the follow-up period.Conclusions:Polypectomy,a central depression,and treatment in the early period were risk factors for IR.Further,an atypical hyperemic appearance and treatment in the early period were significant predisposing factors for inappropriate choice of polypectomy.For histologically incompletely resected small RNETs,follow-up may be a safe and feasible alternative to rigorous salvage therapy.

Comparative analysis of the short and medium-term efficacy of the Da Vinci robot versus laparoscopic total mesangectomy for rectal cancer

BACKGROUND The Da Vinci robot-assisted surgery technique has been widely used in laparo-scopic mesangectomy for rectal cancer.However,the short-term efficacy of these procedures compared to traditional laparoscopic surgery remains controversial.The purpose of this study was to compare and analyze the short-and medium-term efficacy of Da Vinci robot and laparoscopic surgery in total mesangectomy(TME)for rectal cancer,so as to provide guidance and reference for clinical practice.AIM To investigate the safety and long-term efficacy of robotic and laparoscopic total mesorectal resection for the treatment of rectal cancer.METHODS The clinicopathologic data of 240 patients who underwent TME for rectal cancer in the Anorectal Department of People’s Hospital of Xinjiang Uygur Autonomous Region from August 2018 to March 2023 were retrospectively analyzed.Among them,112 patients underwent laparoscopic TME(L-TME)group,and 128 patients underwent robotic TME(R-TME)group.The intraoperative,postoperative,and follow-up conditions of the two groups were compared.RESULTS The conversion rate of the L-TME group was greater than that of the R-TME group(5.4%vs 0.8%,χ^(2)=4.417,P=0.036).The complication rate of the L-TME group was greater than that of the R-TME group(32.1%vs 17.2%,χ^(2)=7.290,P=0.007).The percentage of positive annular margins in the L-TME group was greater than that in the R-TME group(7.1%vs 1.6%,χ^(2)=4.658,P=0.031).The 3-year disease-free survival(DFS)rate and overall survival(OS)rate of the L-TME group were lower than those of the R-TME group(74.1%vs 85.2%,χ^(2)=4.962,P=0.026;81.3%vs 91.4%,χ^(2)=5.494,P=0.019);in patients with American Joint Committee on Cancer stage Ⅲ DFS rate and OS rate in the L-TME group were significantly lower than those in the R-TME group(52.5%vs 76.1%,χ^(2)=5.799,P=0.016;65.0%vs 84.8%,χ^(2)=4.787,P=0.029).CONCLUSION Compared with the L-TME group,the R-TME group had a better tumor prognosis and was more favorable for patients with rectal cancer,especially for patients with stage Ⅲ rectal cancer.

Endoscopic ultrasonography and submucosal resection in the diagnosis and treatment of rectal carcinoid tumors

Rectal carcinoid tumors are often diagnosed as .submucosal tumors on radiological or endoscopic examinations. Usually, its definite size and character, the infiltration of muscularis propria and vessels can not be correctly diagnosed preoperatively. In recent years, endoscopic ultrasonography （EUS） has been used in the diagnosis of submucosal tumors of the gastrointestinal tracts , Conventional endoscopic polypectomy allows local excision of local tumors, but is often associated with tumor involvement of the resection margin necessitates further interventions.

Simultaneous laparoscopic excision for rectal carcinoma and synchronous hepatic metastasis

Background Rectal carcinoma patients are often accompanied by hepatic metastasis. The aim of this study was to evaluate the therapeutic efficacy of simultaneous laparoscopic excision for rectal carcinoma with synchronous hepatic metastasis.Methods A total of 41 patients with rectal carcinoma and synchronous hepatic metastasis detected by CT scan were included in this study. Among them, 23 patients underwent laparoscopic surgery and 18 patients underwent traditional open surgery to simultaneously remove the rectal tumor and hepatic metastasis lesions. All patients received postoperative adjuvant chemotherapy. All the patients were followed up from 36 to 72 months （mean 45.3 months）.Results All the operations were performed successfully and no patient was turned to open surgery in laparoscopic group. The mean blood loss, the mean postoperative hospital stay, the mean blood transfusion and the mean intestinal functional recovery time showed a significant difference between the two groups （P〈0.05）. The 1-, 3- and 5-year survival rates were 82.6%, 43.5% and 8.6% in the laparoscopic group, without significant difference compared with the open group （77.8%, 38.9% and 0） （P〉0.05）.Conclusions Simultaneous laparoscopic excision for rectal carcinoma and synchronous hepatic metastasis is safe and effective with similar survival achieved by the traditional open abdominal surgery.