Prevalence, risk factors, and BRAF mutation of colorectal sessile serrated lesions among Vietnamese patients

BACKGROUND Sessile serrated lesions(SSLs)are considered precancerous colorectal lesions that should be detected and removed to prevent colorectal cancer.Previous studies in Vietnam mainly investigated the adenoma pathway,with limited data on the serrated pathway.AIM To evaluate the prevalence,risk factors,and BRAF mutations of SSLs in the Vietnamese population.METHODS This is a cross-sectional study conducted on patients with lower gastrointestinal symptoms who underwent colonoscopy at a tertiary hospital in Vietnam.SSLs were diagnosed on histopathology according to the 2019 World Health Organi-zation classification.BRAF mutation analysis was performed using the Sanger DNA sequencing method.The multivariate logistic regression model was used to determine SSL-associated factors.RESULTS There were 2489 patients,with a mean age of 52.1±13.1 and a female-to-male ratio of 1:1.1.The prevalence of SSLs was 4.2%[95%confidence interval(CI):3.5-5.1].In the multivariate analysis,factors significantly associated with SSLs were age≥40[odds ratio(OR):3.303;95%CI:1.607-6.790],male sex(OR:2.032;95%CI:1.204-3.429),diabetes mellitus(OR:2.721;95%CI:1.551-4.772),and hypertension(OR:1.650,95%CI:1.045-2.605).The rate of BRAF mutations in SSLs was 35.5%.CONCLUSION The prevalence of SSLs was 4.2%.BRAF mutations were present in one-third of SSLs.Significant risk factors for SSLs included age≥40,male sex,diabetes mellitus,and hypertension.

Diagnostic performance of narrow-band imaging international colorectal endoscopic and Japanese narrow-band imaging expert team classification systems for colorectal cancer and precancerous lesions

BACKGROUND In recent years,two new narrow-band imaging(NBI)classifications have been proposed:The NBI international colorectal endoscopic(NICE)classification and Japanese NBI expert team(JNET)classification.Most validation studies of the two new NBI classifications were conducted in classification setting units by experienced endoscopists,and the application of use in different centers among endoscopists with different endoscopy skills remains unknown.AIM To evaluate clinical application and possible problems of NICE and JNET classification for the differential diagnosis of colorectal cancer and precancerous lesions.METHODS Six endoscopists with varying levels of experience participated in this study.Eighty-seven consecutive patients with a total of 125 lesions were photographed during non-magnifying conventional white-light colonoscopy,non-magnifying NBI,and magnifying NBI.The three groups of endoscopic pictures of each lesion were evaluated by the six endoscopists in randomized order using the NICE and JENT classifications separately.Then we calculated the six endoscopists’sensitivity,specificity,accuracy,positive predictive value,and negative predictive value for each category of the two classifications.RESULTS The sensitivity,specificity,and accuracy of JNET classification type 1 and 3 were similar to NICE classification type 1 and 3 in both the highly experienced endoscopist(HEE)and less-experienced endoscopist(LEE)groups.The specificity of JNET classification type 1 and 3 and NICE classification type 3 in both the HEE and LEE groups was>95%,and the overall interobserver agreement was good in both groups.The sensitivity of NICE classification type 3 lesions for diagnosis of SM-d carcinoma in the HEE group was significantly superior to that in the LEE group(91.7%vs 83.3%;P=0.042).The sensitivity of JNET classification type 2B lesions for the diagnosis of high-grade dysplasia or superficial submucosal invasive carcinoma in the HEE and LEE groups was 53.8%and 51.3%,respectively.Compared with other types of JNET classification,the diagnostic ability of type 2B was the weakest.CONCLUSION The treatment strategy of the two classification type 1 and 3 lesions can be based on the results of endoscopic examination.JNET type 2B lesions need further examination.

Prevention of late complications with coverage agents in endoscopic resection of colorectal lesions: Current landscape in gastrointestinal endoscopy

Endoscopic removal of large(≥20 mm)non-pedunculated colorectal lesions(LNPCLs)may result in major adverse events,such as delayed bleeding(DB)and delayed perforation(DP),despite closure of the mucosal defects with clips.Topical application of a coverage agent refers to the creation of a shield with a biocompatible medical device(tissue or hydrogel)with proven bioactive properties.Coverage of the eschar after endoscopic resection provides shielding protection to prevent delayed complications.The aim of the present review was to systematically collect and review the currently available literature regarding the prevention of DB and DP with coverage agents after endoscopic mucosal resection or endoscopic submucosal dissection of LNPCLs.

Lack of estrogen receptors expression in malignant and pre-malignant colorectal lesions in Egyptian patients

Background: incidence of Colorectal cancer (CRC) is increasing globally. In Egypt, CRC ranks the sixth most common cancer in males and the fifth in females. Aim: To assess the expression of estrogen receptors (alpha and beta) in pre-malignant (adenomatous polyps and IBD), malignant colorectal lesions and normal colonic mucosa in group of Egyptian patients. Methods: This prospective study was done on 45 patients presenting with colonic symptoms, patients were divided into four groups;15 CRC patients, 10 patients with adenomatous polyps, 10 IBD patients and 10 patients in the control group. Patients subjected to: Stool analysis, FOBT, CBC, CEA, Abdominal ultrasound & colonoscopy and biopsy (number = 80), Pathological, immunohistochemistry and RT- PCR quantification of ERα and ERβ were done. Results: Mean age: 39.2 (12 - 73), gender: M/F: 28/17. Bleeding per rectum was the commonest presentation;29/45 (64.4%). CEA was significantly elevated in the CRC group compared with other studied groups (1692 mg/L vs. 4.0, 4.0 and 4.4 mg/L). Ultrasonography of the studied patients showed that metastatic CRC: 3/15 (20%);Colonic wall thickening: 5/15 (33.3%), 1/10 showed colonic polypoidal lesions in adenomatous polyps groups, in IBD group: 4/10 (40%) showed colonic and ileocecal thicknening. All the studied patients showed negative results for estrogen receptors (alpha and beta) by the use of immunohistochemistry staining and RT-PCR technique. Conclusion: Role of estrogen receptors in the colonic mucosa, precancerous and colorectal cancer is doubtful, contradictory results with some literature data could be due to racial and genetic difference in the studied population.

Randomised controlled trial comparing modified Sano's and narrow band imaging international colorectal endoscopic classifications for colorectal lesions

AIM To assess the utility of modified Sano′s(MS) vs thenarrow band imaging international colorectal endoscopic(NICE) classification in differentiating colorectal polyps.METHODS Patients undergoing colonoscopy between 2013 and 2015 were enrolled in this trial.Based on the MS or the NICE classifications,patients were randomised for real-time endoscopic diagnosis.This was followed by biopsies,endoscopic or surgical resection.The endoscopic diagnosis was then compared to the final(blinded) histopathology.The primary endpoint was the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of differentiating neoplastic and non-neoplastic polyps(MSⅡ/Ⅱo/Ⅲa/Ⅲb vs I or NICE 1 vs 2/3).The secondary endpoints were "endoscopic resectability"(MSⅡ/Ⅱo/Ⅲa vs Ⅰ/Ⅲb or NICE 2 vs 1/3),NPV for diminutive distal adenomas and prediction of post-polypectomy surveillance intervals.RESULTS A total of 348 patients were evaluated.The Sn,Sp,PPV and NPV in differentiating neoplastic polyps from non-neoplastic polyps were,98.9%,85.7%,98.2% and 90.9% for MS;and 99.1%,57.7%,95.4% and 88.2% for NICE,respectively.The area under the receiver operating characteristic curve(AUC) for MS was 0.92(95%CI:0.86-0.98);and AUC for NICE was 0.78(95%CI:0.69,0.88).The Sn,Sp,PPV and NPV in predicting "endoscopic resectability" were 98.9%,86.1%,97.8% and 92.5% for MS;and 98.6%,66.7%,94.7% and 88.9% for NICE,respectively.The AUC for MS was 0.92(95%CI:0.87-0.98);and the AUC for NICE was 0.83(95%CI:0.75-0.90).The AUC values were statistically different for both comparisons(P = 0.0165 and P = 0.0420,respectively).The accuracy for diagnosis of sessile serrated adenoma/polyp(SSA/P) with high confidence utilizing MS classification was 93.2%.The differentiation of SSA/P from other lesions achieved Sp,Sn,PPV and NPV of 87.2%,91.5%,89.6% and 98.6%,respectively.The NPV for predicting adenomas in diminutive rectosigmoid polyps(n = 150) was 96.6% and 95% with MS and NICE respectively.The calculated accuracy of post-polypectomy surveillance for MS group was 98.2%(167 out of 170) and for NICE group was 92.1%(139 out of 151).CONCLUSION The MS classification outperformed the NICE classification in differentiating neoplastic polyps and predicting endoscopic resectability.Both classifications met ASGE PIVI thresholds.

Current progress on the endoscopic features of colorectal sessile serrated lesions

Along with the discovery and refinement of serrated pathways,the World Health Organization amended the classification of digestive system tumors in 2019,recommending the renaming of sessile serrated adenomas/polyps to sessile serrated lesions(SSLs).Given the particularity of the endoscopic appearance of SSLs,it could easily be overlooked and missed in colonoscopy screening,which is crucial for the occurrence of interval colorectal cancer.Existing literature has found that adequate bowel preparation,reasonable withdrawal time,and awareness of colorectal SSLs have improved the quality and accuracy of detection.More particularly,with the continuous advancement and development of endoscopy technology,equipment,and accessories,a potent auxiliary tool is provided for accurate observation and immediate diagnosis of SSLs.Highdefinition white light endoscopy,chromoendoscopy,and magnifying endoscopy have distinct roles in the detection of colorectal SSLs and are valuable in identifying the size,shape,character,risk degree,and potential malignant tendency.This article delves into the relevant factors influencing the detection rate of colorectal SSLs,reviews its characteristics under various endoscopic techniques,and expects to attract the attention of colonoscopists.

Prevention of late complications of endoscopic resection of colorectal lesions with a coverage agent:Current status of gastrointestinal endoscopy

Endoscopic ectomy of large nonpedunculated colorectal lesions(≥20 mm)might cause significant adverse incidents,such as delayed perforation and delayed bleeding,despite the closure of mucosal lesions with clips.The conventional utilization of prophylactic clipping has not decreased the risk of postprocedural delayed adverse events,and additional outcomes and cost-effectiveness research is needed for patients with proximal lesions≥20 mm,in whom prophylactic clipping might be useful.Coverage of the wound after endoscopic excision offers shield protection against delayed concomitant diseases.

From advanced diagnosis to advanced resection in early neoplastic colorectal lesions:Never-ending and trending topics in the 2020s

Colonoscopy represents the most widespread and effective tool for the prevention and treatment of early stage preneoplastic and neoplastic lesions in the panorama of cancer screening.In the world there are different approaches to the topic of colorectal cancer prevention and screening:different starting ages(45-50 years);different initial screening tools such as fecal occult blood with immunohistochemical or immune-enzymatic tests;recto-sigmoidoscopy;and colonoscopy.The key aspects of this scenario are composed of a proper bowel preparation that ensures a valid diagnostic examination,experienced endoscopist in detection of preneoplastic and early neoplastic lesions and open-minded to upcoming artificial intelligence-aided examination,knowledge in the field of resection of these lesions(from cold-snaring,through endoscopic mucosal resection and endoscopic submucosal dissection,up to advanced tools),and management of complications.

Prediction of the severity of colorectal lesion by fecal hemoglobin concentration observed during previous test in the French screening program

BACKGROUND The rate of positive tests using fecal immunochemical test(FIT)does not decrease with subsequent campaigns,but the positive predictive value of advanced neoplasia significantly decreases in subsequent campaign after a first negative test.A relationship between the fecal hemoglobin concentration(Fhb)and the opportunity to detect a colorectal cancer in subsequent campaign has been shown.AIM To predict the severity of colorectal lesions based on Fhb measured during previous colorectal cancer screening campaign.METHODS This etiological study included 293750 patients aged 50-74,living in Auvergne-Rhone-Alpes(France).These patients completed at least two FIT[test_((-1))and test_((0))]between June 2015 and December 2019.Delay between test_((-1))and test_((0))was>1year and test_((-1))result was negative(<150 ngHb/mL).The severity of colorectal lesions diagnosed at test_((0))was described according to Fhb measured at test_((-1))[Fhb_((-1))].The relationship between the severity classified in seven ordinal categories and the predictive factors was analyzed in an ordered multivariate polytomous regression model.RESULTS The test_((0))positive rate was 4.0%,and the colonoscopy completion rate was 97.1%in 11594 patients who showed a positive test_((0)).The colonoscopy detection rate was 77.7%in those 11254 patients who underwent a colonoscopy.A total of 8748 colorectal lesions were detected(including 2182 low-risk-polyps,2400 high-riskpolyp,and 502 colorectal cancer).The colonoscopy detection rate varied significantly with Fhb_((-1))[0 ngHb/mL:75.6%,(0-50 ngHb/mL):77.3%,(50-100 ngHb/mL):88.7%,(100-150 ngHb/mL):90.3%;P=0.001].People with a Fhb_((-1))within(100-150 ngHb/mL)(P=0.001)were 2.6(2.2;3.0)times more likely to have a high severity level compared to those having a Fhb_((-1))value of zero.This risk was reduced by 20%in patients aged 55-59 compared to those aged<55[adjusted odds ratio:0.8(0.6;1.0)].CONCLUSION The study showed that higher Fhb_((-1))is correlated to an increased risk of severity of colorectal lesions.This risk of severity increased among first-time participants(age<55)and the elderly(≥70).To avoid the loss of chance in these age groups,the FIT positivity threshold should be reduced to 100 ngHb/mL.The other alternative would be to reduce the time between the two tests in these age groups from the current 2 years to 1 year.

Deep learning driven colorectal lesion detection in gastrointestinal endoscopic and pathological imaging

Colorectal cancer has the second highest incidence of malignant tumors and is the fourth leading cause of cancer deaths in China.Early diagnosis and treatment of colorectal cancer will lead to an improvement in the 5-year survival rate,which will reduce medical costs.The current diagnostic methods for early colorectal cancer include excreta,blood,endoscopy,and computer-aided endoscopy.In this paper,research on image analysis and prediction of colorectal cancer lesions based on deep learning is reviewed with the goal of providing a reference for the early diagnosis of colorectal cancer lesions by combining computer technology,3D modeling,5G remote technology,endoscopic robot technology,and surgical navigation technology.The findings will supplement the research and provide insights to improve the cure rate and reduce the mortality of colorectal cancer.

Superficial Serrated Adenoma (SuSA): A New Subtype of Serrated Lesions

Superficial serrated adenoma (SuSA) is a new subtype of serrated lesions proposed in recent years, most of which are located in the sigmoid colon or rectum, with typical mixed adenoma and serrated pathological features, and its molecular features are high frequency of KRAS mutation and RSPO fusion or overexpression. At present, it is believed that SuSA has two subtypes: traditional serrated adenoma (TSA)-associated SuSA and isolated SuSA. Solitary SuSA showed faded pedicle-free protuberant lesions under endoscope and lobulated, pp (pit pattern) classification was type II and type IIIH, TSA-associated SuSA showed double-layer eminence, SuSA part showed white flat eminence, pp classification showed type II and IIIH, TSA part showed red tone high eminence, pp was IVH type. SuSA can develop into colorectal cancer through the evolution of TSA, and it can also directly develop into MSS colorectal cancer. In view of the superficial understanding of SuSA and the lack of a complete description of SuSA, this paper review the research progress of SuSA at home and abroad from the origin, endoscope features, histopathological features, molecular biology, differential diagnosis and treatment of SuSA, in order to better promote the understanding and clinical diagnosis of lesions.

Precision in detecting colon lesions:A key to effective screening policy but will it improve overall outcomes?

Colonoscopy is the gold standard for the screening and diagnosis of colorectal cancer,resulting in a decrease in the incidence and mortality of colon cancer.However,it has a 21%rate of missed polyps.Several strategies have been devised to increase polyp detection rates and improve their characterization and delimi-tation.These include chromoendoscopy(CE),the use of other devices such as Endo cuffs,and major advances in endoscopic equipment[high definition,magnification,narrow band imaging,i-scan,flexible spectral imaging color enhancement,texture and color enhancement imaging(TXI),etc.].In the retrospective study by Hiramatsu et al,they compared white-light imaging with CE,TXI,and CE+TXI to determine which of these strategies allows for better definition and delimitation of polyps.They concluded that employing CE associated with TXI stands out as the most effective method to utilize.It remains to be demonstrated whether these results are extrapolatable to other types of virtual CE.Additionally,further investigation is needed in order to ascertain whether this strategy could lead to a reduction in the recurrence of excised lesions and potentially lower the occurrence of interval cancer.

Risk of colorectal polyps in patients with sporadic gastric polyps:A case-control study

AIM:To assess the risk of colonic polyps,adenomas and advanced neoplastic lesions(ANL) in patients with sporadic gastric polyps,especially those with fundic gland polyps(FGP).METHODS:Clinical records of patients who had performed an upper and a lower digestive endoscopy between September 2007 and August 2008 were retrospectively analyzed.A case-control study was carried out,calling patients with gastric polyps as 'cases' and patients without gastric polyps as 'controls'.The risk of colonic polyps,adenomas and ANL(villous component ≥ 25%,size ≥ 10 mm,or high grade dysplasia) was assessed [odds ratio(OR) and its corresponding 95%CI].RESULTS:Two hundred and forty seven patients were analyzed:78 with gastric polyps(cases) and 169 without gastric polyps(controls).Among the cases,the majority of gastric polyps were FGP(80%,CI:69-88) and hyperplastic(20%,CI:12-31);25% had colonic polyps(25% hyperplastic and 68% adenomas,from which 45% were ANL).Among the controls,20% had colonic polyps(31% hyperplastic and 63% adenomas,from which 41% were ANL).The patients with sporadic FGP had an OR of 1.56(CI:0.80-3.04) for colonic polyps,an OR of 1.78(CI:0.82-3.84) for colonic adenomas,and an OR of 0.80(CI:0.21-2.98) for ANL.Similar results were found in patients with gastric polyps in general.CONCLUSION:The results of this study did not show more risk of colorectal adenomas or ANL neither in patients with sporadic gastric polyps nor in those with FGP.

Protein expression trends of DNMT1 in gastrointestinal diseases:From benign to precancerous lesions to cancer

BACKGROUND In recent years,the incidence of gastrointestinal(GI)cancer in China has increased annually.Early detection and appropriate therapy are considered to be the key to treat GI cancer.DNMT1 takes an active part in the advancement of GI cancer,which will change as the disease progresses.But its expression characteristics in the dynamic variations of GI carcinogenesis are still unclear.AIM To investigate the expression characteristics of DNMT1 in different GI diseases.METHODS We detected the expression of DNMT1 in 650 cases of different GI diseases by immunohistochemistry,including 90 cases of chronic superficial gastritis(CSG),72 cases of atrophic gastritis with intestinal metaplasia(AG/GIM),54 cases of low-grade intraepithelial neoplasia(GLIN),66 cases of high-grade intraepithelial neoplasia(GHIN),71 cases of early gastric cancer(EGC),90 cases of normal intestinal mucosa(NIM),54 cases of intestinal low-grade intraepithelial neoplasia(ILIN),71 cases of intestinal high-grade intraepithelial neoplasia(IHIN),and 82 cases of early colorectal cancer(ECRC).RESULTS In the CSG group,all cases showed weakly positive or negative expression of DNMT1.However,in other four groups(AG/GIM,GLIN,GHIN,and EGC),the positive expression rate gradually increased with the severity of the diseases;the negative or weakly positive cases accounted for 55.56%(40/72),38.89%(21/54),1.52%(1/66),and 1.41%(1/71),respectively.Besides,the moderately positive cases were 44.44%(32/72),57.41%(31/54),80.30%(53/66),and 43.66%(31/71),respectively.The strongly positive cases only existed in the GLIN(3.70%,2/54),GHIN(18.18%,12/66),and EGC(54.93%,39/71)groups.The differences between any two groups were statistically significant(P<0.05).Similarly,in the NIM group,cases with weakly positive expression of DNMT1 were predominant(91.11%,82/90),and the rest were moderately positive cases(8.89%,8/90).In the ILIN,IHIN,and ECRC groups,the rates of cases with weak or negative expression of DNMT1 were 46.30%(25/54),12.68%(9/71),and 4.88%(4/82),respectively;with moderately positive expression were 53.70%(29/54),71.83%(51/71),and 34.15%(28/82),respectively;and with strongly positive expression were 0.00%(0/54),15.49%(11/71),and 60.98%(50/82),respectively.The differences between any two groups were also statistically significant(P<0.05).CONCLUSION The overexpression of DNMT1 protein could effectively predict early GI cancers and severe precancerous lesions,which may have potential clinical application value.

Clinical features of upper gastrointestinal serrated lesions: An endoscopy database analysis of 98746 patients

AIM To analyse the clinical features of patients with the serrated lesions in the upper gastrointestinal tract(UPGI) tract.METHODS Patients who underwent routine esophagogastroduodenoscopy(EGD) at the Digestive Endoscopy Centre of General Hospital, Tianjin Medical University between january 2011 and December 2015 were consecutively recruited. Patients with UPGI serrated lesions were consecutively identified. The patients' demographics and histopathology were recorded. The colorectal findings for patients who underwent colonoscopy simultaneously or within six months were also extracted from the colonoscopy database. In addition, we analyseddifferences in colorectal neoplasia detection between the study patients and randomly selected patients matched for age and gender who did not exhibit serrated lesions and who also underwent colonoscopy in the same period.RESULTS A total of 21 patients out of 98746 patients(0.02%) who underwent EGD were confirmed to have serrated lesions with predominantly crenated, sawtooth-like configurations. The mean age of the 21 patients was(55.3 ± 17.2) years, and 11 patients were male(52.4%). In terms of the locations of the serrated lesions, 17 were found in the stomach(including 3 in the cardia, 9 in the corpus and 5 in the antrum), 3 were found in the duodenum, and 1 was found in the esophagus. Serrated lesions were found in different mucosal lesions, with 14 lesions were detected in polyps(8 hyperplastic polyps and 6 serrated adenomas with low grade dysplasia), 3 detected in Ménétrier gastropathy, 3 detected in an area of inflammation or ulcer, and 1 detected in the intramucosal carcinoma of the duodenum. In addition, colonoscopy data were available for 18 patients, and a significantly higher colorectal adenoma detection rate was observed in the UPGI serrated lesions group than in the randomly selected age- and gender-matched group without serrated lesions who also underwent colonoscopy in the same period(38.9% vs 11.1%, OR = 5.091, 95%CI: 1.534-16.890, P = 0.010). The detection rate of advanced adenoma was also higher in the UPGI serrated lesions group(22.2% vs 4.2%, OR = 6.571, 95%CI: 1.322-32.660, P = 0.028).CONCLUSION Serrated lesions in the UPGI were detected in various mucosal lesions with different pathological morphologies. Moreover colonoscopy is recommended for the detection of concurrent colorectal adenoma for these patients.

What could microRNA expression tell us more about colorectal serrated pathway carcinogenesis?

In the last two decades,the vision of a unique carcinogenesis model for colorectal carcinoma(CRC)has completely changed.In addition to the adenoma to carcinoma transition,colorectal carcinogenesis can also occur via the serrated pathway.Small non-coding RNA,known as microRNAs(miRNAs),were also shown to be involved in progression towards malignancy.Furthermore,increased expression of certain miRNAs in premalignant sessile serrated lesions(SSLs)was found,emphasizing their role in the serrated pathway progression towards colon cancer.Since miRNAs function as post-transcriptional gene regulators,they have enormous potential to be used as useful biomarkers for CRC and screening in patients with SSLs particularly.In this review,we have summarized the most relevant information about the specific role of miRNAs and their relevant signaling pathways among different serrated lesions and polyps as well as in serrated adenocarcinoma.Additional focus is put on the correlation between gut immunity and miRNA expression in the serrated pathway,which remains unstudied.

Staging colorectal cancer with the TNM 7^(th):The presumption of innocence when applying the M category

One of the main changes of the current TNM-7 is the elimination of the category MX,since it has been a source of ambiguity and misinterpretation,especially by pathologists.Therefore the ultimate staging would be better performed by the patient's clinician who can classify the disease M0(no distant metastasis) or M1(presence of distant metastasis),having access to the completeness of data resulting from clinical examination,imaging workup and pathology report.However this important change doesn't take into account the diagnostic value and the challenge of small indeterminate visceral lesions encountered,in particular,during radiological staging of patients with colorectal cancer.In this article the diagnosis of these lesions with multiple imaging modalities,their frequency,significance and relevance to staging and disease management are described in a multidisciplinary way.In particular the interplay between clinical,radiological and pathological staging,which are usually conducted independently,is discussed.The integrated approach shows that there are both advantages and disadvantages to abandoning the MX category.To avoid ambiguity arising both by applying and interpreting MX category for stage assigning,its abandoning seems reasonable.The recognition of the importance of small lesion characterization raises the need for applying a separate category;therefore a proposal for their categorization is put forward.By using the proposed categorization the lack of consideration for indeterminate visceral lesions with the current staging system will be overcome,also optimizing tailored follow-up.

Serrated lesions:A challenging enemy

The serrated pathway accounts for 30%-35%of colorectal cancer(CRC).Unlike hyperplastic polyps,both sessile serrated lesions(SSLs)and traditional serrated adenomas are premalignant lesions,yet SSLs are considered to be the principal serrated precursor of CRCs.Serrated lesions represent a challenge in detection,classification,and removal–contributing to post-colonoscopy cancer.Therefore,it is of the utmost importance to characterize these lesions properly to ensure complete removal.A retrospective cohort study developed a diagnostic scoring system for SSLs to facilitate their detection endoscopically and subsequent removal.From the study,it can be ascertained that both indistinct border and mucus cap are essential in both recognizing and diagnosing serrated lesions.The proximal colon poses technical challenges for some endoscopists,which is why high-quality colonoscopy plays such an important role.The indistinct border of some SSLs poses another challenge due to difficult complete resection.Overall,it is imperative that gastroenterologists use the key features of mucus cap,indistinct borders,and size of at least five millimeters along with a high-quality colonoscopy and a good bowel preparation to improve the SSL detection rate.

Colorectal cancer screening: Comparison of transferrin and immuno fecal occult blood test

AIM: To evaluate the sensitivity and specificity of transfesrrin dipstick test (Tf) in colorectal cancer (CRC) screening and precancerous lesions screening. METHODS: Eight hundreds and sixty-one individuals at high-risk for CRC were recruited. Six hundreds and eleven subsequently received the three fecal occult blood tests and colonoscopy with biopsy performed as needed. Fecal samples were obtained on the day before colonoscopy. Tf, immuno fecal occult blood test (IFOBT) and guaiac fecal occult blood test (g-FOBT) were performed simultaneously on the same stool. To minimize false-negative cases, all subjects with negative samples were asked to provide an additional stool specimen for a second test even a third test. If the results were all negative after testing three repeated samples, the subject was considered a true negative. The performance characteristics of Tf for detecting CRC and precancerous lesions were examined and compared to those of IFOBT and the combination of Tf, IFOBT and g-FOBT. RESULTS: A total of six hundreds and eleven subjects met the study criteria including 25 with CRC and 60 with precancerous lesions. Sensitivity for detecting CRC was 92% for Tf and 96% for IFOBT, specificities of Tf and IFOBT were both 72.0% (95% CI: 68.2%-75.5%; χ2 = 0.4, P > 0.05); positive likelihood ratios of those were 3.3 (95% CI: 2.8-3.9) and 3.4 (95% CI: 2.9-4.0), respectively. In precancerous lesions, sensitivities for Tf and IFOBT were 50% and 58%, respectively (χ 2 = 0.8, P > 0.05); specificities of Tf and IFOBT were 71.5% (95% CI: 67.6%-75.1%) and 72.2% (95% CI: 68.4%-75.8%); positive likelihood ratios of those were 1.8 (95% CI: 1.3-2.3) and 2.1 (95% CI: 1.6-2.7), respectively; compared to IFOBT, g-FOBT+ Tf+ IFOBT had a significantly higher positive rate for precancerous lesions (83% vs 58%, respectively; χ 2 = 9.1, P < 0.05). In patients with CRC and precancerous lesions, the sensitivities of Tf and IFOBT were 62% and 69% (χ 2 = 0.9, P > 0.05); specificities of those were 74.5% (95% CI: 70.6%-78.1%) and 75.5% (95% CI: 71.6%-79.0%); positive likelihood ratios of those were 2.5 (95% CI: 2.0-3.1) and 2.8 (95% CI: 2.3-3.5). Compared to IF-OBT alone, combining g-FOBT, IFOBT and Tf led to significantly increased sensitivity for detecting CRC and cancerous lesions (69% vs 88%, respectively; χ 2 = 9.0, P < 0.05). CONCLUSION: Tf dipstick test might be used as an ad- ditional tool for CRC and precancerous lesions screening in a high-risk cohort.

Non-polypoid colorectal neoplasms:Classification,therapy and follow-up

In the last years,an increasing interest has been raised on non-polypoid colorectal tumors(NPT) and in particular on large flat neoplastic lesions beyond 10 mm tending to grow laterally,called laterally spreading tumors(LST).LSTs and large sessile polyps have a greater frequency of high-grade dysplasia and local invasiveness as compared to pedunculated lesions of the same size and usually represent a technical challenge for the endoscopist in terms of either diagnosis and resection.According to the Paris classification,NPTs are distinguished in slightly elevated(0-Ⅱa,less than 2.5 mm),flat(0-Ⅱb) or slightly depressed(0-Ⅱc).NPTs are usually flat or slightly elevated and tend to spread laterally while in case of depressed lesions,cell proliferation growth progresses in depth in the colonic wall,thus leading to an increased risk of submucosal invasion(SMI) even for smaller neoplasms.NPTs may be frequently missed by inexperienced endoscopists,thus a careful training and precise assessment of all suspected mucosal areas should be performed.Chromoendoscopy or,if possible,narrow-band imaging technique should be considered for the estimation of SMI risk of NPTs,and the characterization of pit pattern and vascular pattern may be useful to predict the risk of SMI and,therefore,to guide the therapeutic decision.Lesions suitable to endoscopic resection are those confined to the mucosa(or superficial layer of submucosa in selected cases) whereas deeper invasion makes endoscopic therapy infeasible.Endoscopic mucosal resection(EMR,piecemeal for LSTs > 20 mm,en bloc for smaller neoplasms) remains the first-line therapy for NPTs,whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory and cannot be achieved by means of EMR.After piecemeal EMR,follow-up colonoscopy should be performed at 3 mo to assess resection completeness.In case of en bloc resection,surveillance colonoscopy should be scheduled at 3 years for adenomatous lesions ≥ 1 cm,or in presence of villous features or high-grade dysplasia patients(regardless of the size),while less intensive surveillance(colonoscopy at 5-10 years) is needed in case of single(or two) NPT < 1 cm presenting tubular features or low-grade dysplasia at histology.