Endoscopic management of colorectal polyps: From benign to malignant polyps

Colorectal cancer(CRC)is the third most common cancer worldwide and the second leading cause of cancer related death in the world.The early detection and removal of CRC precursor lesions has been shown to reduce the incidence of CRC and cancer-related mortality.Endoscopic resection has become the first-line treatment for the removal of most precursor benign colorectal lesions and selected malignant polyps.Detailed lesion assessment is the first critical step in the evaluation and management of colorectal polyps.Polyp size,location and both macro-and micro-features provide important information regarding histological grade and endoscopic resectability.Benign polyps and even malignant polyps with superficial submucosal invasion and favorable histological features can be adequately removed endoscopically.When compared to surgery,endoscopic resection is associated with lower morbidity,mortality,and higher patient quality of life.Conversely,malignant polyps with deep submucosal invasion and/or high risk for lymph node metastasis will require surgery.From a practical standpoint,the most appropriate strategy for each patient will need to be individualized,based not only on polyp-and patient-related characteristics,but also on local resources and expertise availability.In this review,we provide a broad overview and present a potential decision tree algorithm for the evaluation and management of colorectal polyps that can be widely adopted into clinical practice.

Long-term outcomes after endoscopic removal of malignant colorectal polyps:Results from a 10-year cohort

BACKGROUND Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging,and evidence regarding a surveillance-only strategy is limited.AIM To evaluate long-term outcomes after endoscopic removal of malignant colorectal polyps.METHODS A single-center retrospective cohort study was conducted to evaluate outcomes after endoscopic removal of malignant colorectal polyps between 2010 and 2020.Residual disease rate and nodal metastases after secondary surgery and local and distant recurrence rate for those with at least 1 year of follow-up were invest-igated.Event rates for categorical variables and means for continuous variables with 95%confidence intervals were calculated,and Fisher’s exact test and Mann-Whitney test were performed.Potential risk factors of adverse outcomes were RESULTS In total,135 lesions(mean size:22.1 mm;location:42%rectal)from 129 patients(mean age:67.7 years;56%male)were enrolled.The proportion of pedunculated and non-pedunculated lesions was similar,with en bloc resection in 82%and 47%of lesions,respectively.Tumor differentiation,distance from resection margins,depth of submucosal invasion,lymphovascular invasion,and budding were reported at 89.6%,45.2%,58.5%,31.9%,and 25.2%,respectively.Residual tumor was found in 10 patients,and nodal metastasis was found in 4 of 41 patients who underwent secondary surgical resection.Univariate analysis identified piecemeal resection as a risk factor for residual malignancy(odds ratio:1.74;P=0.042).At least 1 year of follow-up was available for 117 lesions from 111 patients(mean follow-up period:5.59 years).Overall,54%,30%,30%,11%,and 16%of patients presented at the 1-year,3-year,5-year,7-year,and 9-10-year surveillance examinations.Adverse outcomes occurred in 9.0%(local recurrence and dissemination in 4 patients and 9 patients,respectively),with no difference between patients undergoing secondary surgery and surveillance only.CONCLUSION Reporting of histological features and adherence to surveillance colonoscopy needs improvement.Long-term adverse outcome rates might be higher than previously reported,irrespective of whether secondary surgery was performed.

Malignant colorectal polyps

Nowadays, the number of cases in which malignant colorectal polyps are removed is increasing due to colorectal cancer screening programmes. Cancerous polyps are classified into non-invasive high grade neoplasia (NHGN), when the cancer has not reached the muscularis mucosa, and malignant polyps, classed as T1, when they have invaded the submucosa. NHGN is considered cured with polypectomy, while the prognosis for malignant polyps depends on various morphological and histological factors. The prognostic factors include, sessile or pedunculated morphology of the polyp, whether partial or en bloc resection is carried out, the degree of differentiation of the carcinoma, vascular or lymphatic involvement, and whether the polypectomy resection margin is tumor free. A malignant polyp at T1 is considered cured with polypectomy ifit is a pedunculated polyp (Ip of the Paris classification), it has been completely resected, it is not poorly differentiated, the resection edge is not affected by the tumor and there is no vascular or lymphatic involvement. The sessile malignant polyp (Is of the Paris classification) at T1 is considered not cured with polypectomy. Only in some cases (e.g. older people with high surgical risk) local excision(polypectomy or endoscopic submucosal dissection or conventional endoscopic mucosal resection) is considered the definitive treatment.

Management of malignant colon polyps:Current status and controversies

Colon cancer remains a significant clinical problem worldwide and in the United States it is the third most common cancer diagnosed in men and women.It is generally accepted that most malignant neoplasms of the colon arise from precursor adenomatous polyps.This stepwise progression of normal epithelium to carcinoma,often with intervening dysplasia,occurs as a result of multiple sequential,genetic mutations-some are inherited while others are acquired.Malignant polyps are defined by the presence of cancer cells invading through the muscularis mucosa into the underlying submucosa(T1).They can appear benign endoscopically but the presence of malignant invasion histologically poses a difficult and often controversial clinical scenario.Emphasis should be initially focused on the endoscopic assessment of these lesions.Suitable polyps should be resected en-bloc,if possible,to facilitate thorough evaluation by pathology.In these cases,proper attention must be given to the risks of residual cancer in the bowel wall or in the surrounding lymph nodes.If resection is not feasible endoscopically,thenthese patients should be referred for surgical resection.This review will discuss the important prognostic features of malignant polyps that will most profoundly affect this risk profile.Additionally,we will discuss effective strategies for their overall management.

Outcome of gall bladder polypoidal lesions detected by transabdominal ultrasound scanning: A nine year experience

AIM: To determine the outcome of polypoidal lesions within the gall bladder (PLG) diagnosed by trans-abdominal scanning.METHODS: A nine-year (1993-2002) retrospective casenote review of all patients who underwent ultrasound scanning after referral to a single Upper GI Surgeon at a District General Hospital was conducted. Patients who were diagnosed with a PLG were included in our study. A database was constructed and patient details, investigations including ultrasound scan (USS) findings, treatment and histology and final diagnosis were recorded. RESULTS: Twenty-three (out of 651) patients were diagnosed pre-operatively by USS to have a polyp-likegall bladder lesion (PLG). Post cholecystectomy histological examination revealed 12 gallstones, 7 cholesterol polyps, 3 adenocarcinomas within polyps and 1 normal gall bladder. The specificity of USS in the diagnosis of PLG was 92.3%. All the true polyps were malignant. Overall USS had 66.66% sensitivity and 100% specificity in the pre-operative suspicion of malignancy. Using size greater than 10 mm as measured on USS as a cut-off, we find 100% sensitivity and 86.95% specificity with a positive predictive value of 50% in the diagnosis of malignancy in PLG.CONCLUSION: A large number of PLG are in fact calculi within diseased gall bladder. In cases of gall bladder polyps more then 10 mm in size on USS further imaging (crosssectional and/or EUS) is indicated prior to surgery. This will help in the optimal management of patients and avoid histological surprises.

Gallbladder polypoid lesions:Current practices and future prospects

Gallbladder polypoid lesions(GPLs)refer to any elevated lesion of the mucosal surface of the gallbladder wall,and the prevalence is estimated to be between 0.9%and 12.1%.GPLs include benign polyps and malignant polyps.Benign polyps are further classified as non-neoplastic polyps and neoplastic polyps.Cholesterol polyps are the most common benign polyps and adenocarcinoma is the main type of malignant polyp.Hepatitis B virus infection,liver function abnormalities,dyslipidemia,and obesity are the main risk factors for GPLs.Studies of biological mechanisms have focused on malignant gallbladder polyps,the development of which is regulated by hormone levels in vivo,gut microbiota,inflammation,oxidative stress,Salmonella typhimurium,and related molecules.Diagnostic modalities include chemical examination and imaging examination,with imaging examination currently being the mainstay.Treatment of patients with GPLs is based on the presence or absence of symptoms,age,size of the polyps,tendency of the polyp to increase,and risk factors for symptomatic malignancy to determine whether surgery should be performed.