Detection and analysis of serum bile acid profile in patients with colonic polyps

BACKGROUND Analyzing the variations in serum bile acid(BA)profile can provide a certain biological basis for early warning and prevention of various diseases.There is currently no comprehensive study on the relationship between the serum BA profile and colonic polyps.AIM To study the serum BA profile detection results of patients with colonic polyps,and analyze the correlation between BA and colonic polyps.METHODS From January 1,2022,to June 1,2023,204 patients with colonic polyps who were diagnosed and treated at Zhongda Hospital Southeast University were chosen as the study subjects,and 135 non-polyp people who underwent physical examination were chosen as the control group.Gathering all patients'clinical information,typical biochemical indicators,and BA profile.RESULTS Compared with the control group,the serum levels of taurocholic acid,glycocholic acid,glycochenodeoxycholic acid,and taurochenodeoxycholic acid in the colonic polyp group were significantly higher than those in the control group,while the content of deoxycholic acid(DCA)was lower than that in the control group(P<0.05).When colonic polyps were analyzed as subgroups,it was shown that there was a strong correlation between changes in the BA profile and polyp diameter,location,morphology,pathological kind,etc.CONCLUSION The serum BA profile showed significant changes in patients with colonic polyps,with a significant increase in primary conjugated BA content and a decrease in secondary free bile acid DCA content.There is a certain correlation between primary free BA and pathological parameters of polyps.

Predictive factors and model validation of post-colon polyp surgery Helicobacter pylori infection

BACKGROUND Recently,research has linked Helicobacter pylori(H.pylori)stomach infection to colonic inflammation,mediated by toxin production,potentially impacting colorectal cancer occurrence.AIM To investigate the risk factors for post-colon polyp surgery,H.pylori infection,and its correlation with pathologic type.METHODS Eighty patients who underwent colon polypectomy in our hospital between January 2019 and January 2023 were retrospectively chosen.They were then randomly split into modeling(n=56)and model validation(n=24)sets using R.The modeling cohort was divided into an H.pylori-infected group(n=37)and an H.pylori-uninfected group(n=19).Binary logistic regression analysis was used to analyze the factors influencing the occurrence of H.pylori infection after colon polyp surgery.A roadmap prediction model was established and validated.Finally,the correlation between the different pathological types of colon polyps and the occurrence of H.pylori infection was analyzed after colon polyp surgery.RESULTS Univariate results showed that age,body mass index(BMI),literacy,alcohol consumption,polyp pathology type,high-risk adenomas,and heavy diet were all influential factors in the development of H.pylori infection after intestinal polypectomy.Binary multifactorial logistic regression analysis showed that age,BMI,and type of polyp pathology were independent predictors of the occurrence of H.pylori infection after intestinal polypectomy.The area under the receiver operating characteristic curve was 0.969[95%confidence interval(95%CI):0.928–1.000]and 0.898(95%CI:0.773–1.000)in the modeling and validation sets,respectively.The slope of the calibration curve of the graph was close to 1,and the goodness-of-fit test was P>0.05 in the two sets.The decision analysis curve showed a high rate of return in both sets.The results of the correlation analysis between different pathological types and the occurrence of H.pylori infection after colon polyp surgery showed that hyperplastic polyps,inflammatory polyps,and the occurrence of H.pylori infection were not significantly correlated.In contrast,adenomatous polyps showed a significant positive correlation with the occurrence of H.pylori infection.CONCLUSION Age,BMI,and polyps of the adenomatous type were independent predictors of H.pylori infection after intestinal polypectomy.Moreover,the further constructed column-line graph prediction model of H.pylori infection after intestinal polypectomy showed good predictive ability.

Schistosomal(bilharzial)polyps:Travel through the colon and beyond

Schistosomiasis(bilharziasis)is a major neglected tropical disease.It is endemic in many tropical and subtropical communities.Schistosomal polyps(S.polyps)are not uncommon presentation of this infection.Although the colon is the most commonly affected organ,many other organs are affected.S.polyps are associated with a variable range of morbidity independent of the Schistosomal infection.S.polyps are frequently described in endemic areas and increasingly reported in non-endemic areas mainly among immigrants and visitors to the endemic areas.This review aimed to increase awareness of practitioners,especially gastroenterologists,for this peculiar type of polyps caused by this neglected infection hence improving patient outcomes.Web-based search of different databases was conducted for the literature focusing the development of S.polyps in the colon and other organs with analysis of the clinical manifestations,diagnosis and treatment.The following key words were used in the search,“Schistosomiasis”OR“Bilharziasis”AND“Polyps”OR“Polyp”AND“Colon”OR“Small intestine”OR“Duodenum”OR“Stomach”OR“Esophagus”OR”Gallbladder”OR”Pharynx”OR“Larynx”OR“Trachea”OR”Urinary bladder”OR“Ureter”OR“Renal Pelvis”OR“Urethra”.All publication types including case reports,case series,original research,and review articles were retrieved and analyzed.S.polyps are not infrequent presentation of acute or chronic Schistosomal infection.S.polyps are described in many organs including the bowel,genitourinary tract,skin,gallbladder and the larynx.Presentation of S.polyps is variable and depends on the site,number as well as the polyp size.The relationship of S.polyps to malignant transformation is a matter of discussion.Presence of S.polyps is sometimes the only manifestation of Schistosomiasis.Small polyps can be treated medically with praziquantel,while large accessible polyps are amendable for endoscopic excision through different polyp resection techniques.However,huge,complicated,non-accessible and suspicious polyps are indicated for surgical management or advanced endoscopic resection when appropriate.Clinicians and endoscopists should be aware about these facts when treating patients living in,immigrated from or visiting endemic areas.

Automated Colonic Polyp Detection and Classification Enabled Northern Goshawk Optimization with Deep Learning

The major mortality factor relevant to the intestinal tract is the growth of tumorous cells(polyps)in various parts.More specifically,colonic polyps have a high rate and are recognized as a precursor of colon cancer growth.Endoscopy is the conventional technique for detecting colon polyps,and considerable research has proved that automated diagnosis of image regions that might have polyps within the colon might be used to help experts for decreasing the polyp miss rate.The automated diagnosis of polyps in a computer-aided diagnosis(CAD)method is implemented using statistical analysis.Nowadays,Deep Learning,particularly throughConvolution Neural networks(CNN),is broadly employed to allowthe extraction of representative features.This manuscript devises a new Northern Goshawk Optimization with Transfer Learning Model for Colonic Polyp Detection and Classification(NGOTL-CPDC)model.The NGOTL-CPDC technique aims to investigate endoscopic images for automated colonic polyp detection.To accomplish this,the NGOTL-CPDC technique comprises of adaptive bilateral filtering(ABF)technique as a noise removal process and image pre-processing step.Besides,the NGOTL-CPDC model applies the Faster SqueezeNet model for feature extraction purposes in which the hyperparameter tuning process is performed using the NGO optimizer.Finally,the fuzzy Hopfield neural network(FHNN)method can be employed for colonic poly detection and classification.A widespread simulation analysis is carried out to ensure the improved outcomes of the NGOTL-CPDC model.The comparison study demonstrates the enhancements of the NGOTL-CPDC model on the colonic polyp classification process on medical test images.

Association between CYP24A1 polymorphisms and the risk of colonic polyps and colon cancer in a Chinese population

AIM To determine the pathogenesis and potential single nucleotide polymorphisms(SNPs) as screening sites for colonic polyps,colon cancer and ulcerative colitis,and to analyze the possible association between these genetic polymorphisms and the three diseases. METHODS We evaluated genetic polymorphisms in 144 newly diagnosed colonic polyp patients,96 colon cancer patients and 44 ulcerative colitis patients. The four SNPs genotyped were rs4809957,rs6068816,rs6091822 and rs8124792. The control group consisted of 504 East Asians enrolled in the 1000 Genomes Project. Correlations between CYP24A1 SNPs and the diseases were analyzed by Fisher's exact probability test.RESULTS CYP24A1 polymorphisms rs4809957 A/G and rs6068816 C/T showed a statistically significant association with risk of the three diseases,when both the genotypes and allele frequencies were considered. With regard to rs6091822 G/T,all three diseases were related to risk allele carriers(GT + TT) vs wild-type(GG),but the associations between the allele frequencies and the diseases were not significant. The risk of colonic polyps and colon cancer was related to the allele frequencies of rs8124792 G/A,and this association remained for genotype frequencies of this SNP. CONCLUSION Four SNPs are related to the risk of colonic polyps and colon cancer. G allele in rs6091822 G/T may play an anti-cancer role only if it is homozygous. The A allele,which is a minor component of rs8124792,may be indicated in the diagnosis of colonic polyps or colon cancer rather than ulcerative colitis.

Colonic polyps: Is it useful to characterize them with advanced endoscopy?

There have been major developments in endoscopic imaging techniques in recent years.Endoscopes with high definition and magnification can provide high quality images that allow for the histological estimation of lesions in vivo and in situ when combined with ancillary enhancement techniques such as chromoendoscopy(CE)and virtual CE(narrow band imaging fujinon intelligent chromoendoscopy,or i-Scan).Despite the enormous potential for these advanced techniques,their value and feasibility in the clinic are still doubted,particularly in cases of colonic polyps that are slated for removal,where in vivo characterization may be deemed unnecessary.However,there are several advantages offered by such advanced endoscopic imaging.CE with or without magnification demonstrates highly accurate histology and invasion depth prediction,and virtual CE is a feasible and less cumbersome alternative to CE in terms of histological estimation,though not sufficiently accurate for depth invasion prediction.Furthermore,the supplementary information provided by advanced imaging systems can assist the endoscopist in the selection of a strategic approach,such as in deciding whether a colonic lesion should be resected,left in situ,or requires more intensive surgical treatment.Lastly,advanced high-resolution imaging techniques may be more cost effective,such that histopathology of lowrisk lesions following resection can be eliminated.The results of these evaluations and comparisons with traditional CE are presented and discussed.Taken together,the benefits provided by these advanced capabilities justify their development,and advocates their use for the treatment and management of colonic polyps.

Management of local recurrence after endoscopic resection of neoplastic colonic polyps

A proportion of neoplastic polyps are incompletely resected, resulting in local recurrence, especially after resection of large polyps or piecemeal resection. Local recurrences that develop after endoscopic resection of intramucosal neoplasms that lacked risk factors for lymph node metastasis or positive vertical margins are usually treated endoscopically. Endoscopic submucosal dissection(ESD) is indicated for local residual or recurrent early carcinomas after endoscopic resection. However, ESD for such recurrent lesions is technically difficult and is typically a lengthy procedure. Underwater endoscopic mucosal resection(UEMR), which was developed in 2012, is suitable for recurrent or residual lesions and reportedly achieves superior en bloc resection rates and endoscopic complete resection rates than conventional EMR. However, a large recurrent lesion is a negative independent predictor of successful en bloc resection and of complete endoscopic removal. We therefore perform UEMR for relatively small(≤ 10-15 mm) recurrent lesions and ESD for larger lesions.

Prevalence of advanced colonic polyps in asymptomatic Chinese

AIM: To investigate the prevalence of advanced polyps in asymptomatic Chinese and to determine the risk of proximal advanced colonic polyps in subjects with and without polyps in the distal colon.METHODS: Data were collected prospectively during colonoscopic examinations performed in 5 973 subjects as part of health evaluation at our unit from December 1997 to December 2003. Polyps were considered advanced, if they were larger than 10 mm or were tubovillous, villous or malignant. Proximal colon was defined as the splenic flexure and more proximal portions of the colon.RESULTS: Colon polyps were detected in 971 (16.3%)subjects (613 males and 358 females) with their mean age being 56.6±10.7 years. Advanced polyps were noted in 199 (3.3%) individuals. Subjects were sub-classified according to the location of polyps into three groups: distal (569, 58.6%), proximal (284, 29.2%), and combined proximal and distal (118, 12.2%) groups. Subjects with advanced polyps in these three groups were 95 (9.8%),56 (5.8%), and 48 (4.9%) respectively. In the 48 subjects with advanced combined polyps, 13 advanced polyps were distributed at the distal colon, 17 at the proximal colon,and 18 at both. Eighteen colon cancers including 12 at sigmoid and 6 at ascending colon were confirmed by final pathology. The relative risk for advanced proximal polyp according to distal findings was 3.1 (95%CI: 1.3-7.4) for hyperplastic polyp, 2.7 (95%CI: 1.4-5.3) for tubular polyp and 13.5 (95%CI: 5.1-35.4) for advanced polyp as compared to that for no polyp. However, 56 (28.2%) of 199 subjects with advanced polyps had no index polyps at the distal colon and might go undetected under sigmoidoscopic screening.CONCLUSION: Although distal lesions can predict the risk of advanced proximal polyps, a substantial portion of Chinese with advanced proximal polyps is not associated with any distal sentinel lesions. These data have implications for screening policy of colon cancers in Taiwan Residents Chinese.

Comparative effectiveness of i-SCAN^(TM) and high-definition white light characterizing small colonic polyps

AIM:To evaluate accuracy of in vivo diagnosis of adenomatous vs non-adenomatous polyps using i-SCAN digital chromoendoscopy compared with high-definition white light.METHODS:This is a single-center comparative effectiveness pilot study.Polyps(n = 103) from 75 averagerisk adult outpatients undergoing screening or surveillance colonoscopy between December 1,2010 and April 1,2011 were evaluated by two participating endoscopists in an academic outpatient endoscopy center.Polyps were evaluated both with high-definition white light and with i-SCAN to make an in vivo prediction of adenomatous vs non-adenomatous pathology.We determined diagnostic characteristics of i-SCAN and highdefinition white light,including sensitivity,specificity,and accuracy,with regards to identifying adenomatous vs non-adenomatous polyps.Histopathologic diagnosis was the gold standard comparison.RESULTS:One hundred and three small polyps,detected from forty-three patients,were included in the analysis.The average size of the polyps evaluated in the analysis was 3.7 mm(SD 1.3 mm,range 2 mm to 8 mm).Formal histopathology revealed that 54/103(52.4%) were adenomas,26/103(25.2%) were hyperplastic,and 23/103(22.3%) were other diagnoses include "lymphoid aggregates","non-specific colitis," and "no pathologic diagnosis." Overall,the combined accuracy of endoscopists for predicting adenomas was identical between i-SCAN(71.8%,95%CI:62.1%-80.3%) and high-definition white light(71.8%,95%CI:62.1%-80.3%).However,the accuracy of each endoscopist differed substantially,where endoscopist A demonstrated 63.0% overall accuracy(95%CI:50.9%-74.0%) as compared with endoscopist B demonstrating 93.3% overall accuracy(95%CI:77.9%-99.2%),irrespective of imaging modality.Neither endoscopist demonstrated a significant learning effect with i-SCAN during the study.Though endoscopist A increased accuracy using i-SCAN from 59%(95%CI:42.1%-74.4%) in the first half to 67.6%(95%CI:49.5%-82.6%) in the second half,and endoscopist B decreased accuracy using i-SCAN from 100%(95%CI:80.5%-100.0%) in the first half to 84.6%(95%CI:54.6%-98.1%) in the second half,neither of these differences were statistically significant.CONCLUSION:i-SCAN and high-definition white light had similar efficacy predicting polyp histology.Endoscopist training likely plays a critical role in diagnostic test characteristics and deserves further study.

Endoscopic mucosal ablation-an alternative treatment for colonic polyps:Three case reports

BACKGROUND Endoscopic resection of non-invasive lesions is now the standard of care for lesions in the GI tract.However,resection techniques require extensive training,are not available in all endoscopy centers and are prone to complications.Endoscopic mucosal ablation(EMA)is a combination of resection and ablation techniques and it may offer an alternative in the management of such lesions.CASE SUMMARY In this case series we report the successful treatment of three flat colonic polyps using the EMA technique.Two lesions were treatment naïve and 1 was a recurrence after an endoscopic mucosal resection.The sizes ranged from 2 to 4 cm.All three polyps were ablated successfully with no immediate or delayed complications.The recurrence rate at 1 year of follow up was 0%.CONCLUSION Based on this initial experience,we conclude that EMA is a safe and effective technique for the treatment of non-invasive colonic polyps when endoscopic resection techniques are not available.

BRAF inhibitor treatment of melanoma causing colonic polyps:An alternative hypothesis

Colonic polyps may arise from BRAF inhibitor treatment of melanoma, possibly due paradoxical activation of the mitogen-activated protein(MAP)-kinase pathway. In an alternative evidence based scenario, tubular colonic adenomas with APC gene mutations have also been identified in the context of BRAF inhibitor treatment, in the absence of mutations of MAPK genes. A minority of colorectal cancers develop by an alternative "serrated polyp pathway". This article postulates a novel hypothesis, that the established phenotypic and molecular characteristics of serrated colonic polyps/CRC offer an intriguing insight into the pathobiology of BRAF inhibitor induced colonic polyps. Serrated polyps are characterized by a Cp G island methylation phenotype, MLH1 silencing and cellular senescence. They also have BRAF mutations. The contention is that BRAF inhibitor induced polyps mimic the afore-described histology and molecular features of serrated polyps with the exception that instead of the presence of BRAF mutations they induce C-RAF homodimers and B-RAF: C-RAF heterodimers.

Association between colonic polyps and diverticular disease

AIM: To evaluate the association between colonic polyps and diverticular disease in Japan. METHODS: We retrospectively reviewed the medical records of 672 consecutive patients who underwent total colonoscopy between August 2006 and April 2007 at Nishinjo Hospital, Okinawa, Japan. Patients with a history of any of the following were excluded from the study: previous polypectomy, colonic resection, and inflammatory bowel diseases. The association between colonic polyps and diverticular disease was analyzed by logistic regression analysis, adjusted for age and sex. RESULTS: Prevalence of colonic polyps in all patients with diverticular disease was significantly higher than that in those without diverticular disease (adjusted odds ratio 1.7). CONCLUSION: Our data showed that patients with diverticular disease have a higher risk of colonic polyps compared to those without.

Increasing prevalence of advanced colonic polyps in young patients undergoing colonoscopy in a referral academic hospital in Hong Kong

AIM: To investigate the distribution and frequency of advanced polyps over eight years. METHODS: 6424 colonoscopies were reviewed during the study period 1998 to 2005. The study period was subdivided into period Ⅰ: 1998 to 2001 and period Ⅱ: 2002-2005. RESULTS: 1856 polyps (33% advanced polyps) and 328 CRCs were detected. The mean ages of the patients with advanced polyps and cancer were 69.2 ± 12.0 and 71.6 ± 13.8 years, respectively. Advanced polyps were mainly left sided (59.5%). Advanced polyps were found in patients ≤ 60 years from 17.7% in periodⅠto 26.3% in period Ⅱ (P < 0.05), especially in male subjects ≤ 60 years (21.6% vs 31.6%, P < 0.05). Advanced tubulovillous polyps rose from 21.5% in period Ⅰto 29.5% in period Ⅱ (P < 0.05). Whereas cancers in male patients ≤ 60 years were similar in both periods: 23.2% vs 16.5% (P > 0.05). CONCLUSION: Advanced polyps increased significantly in the younger male group in the most recent period and there seems to be a shift towards a proximal location.

Application of Computed Tomographic Colonography in Diagnosis of Colonic Polyps

Objective To assess the clinical values of computed tomographic colonography (CTC) in diagnosis of colonic polyps. Methods Forty-two patients who were clinically suspicious of colonic polyps or underwent colonic polyps screening received examinations with both CTC and conventional colonoscopy. Sixteen- or 64-slice spiral computed tomography and professional imaging processing techniques were used for evaluation. Per-polyp and per-patient results were analyzed. Those by per-polyp were subsequently divided into ≥10mm group, 5-10 mm group, and ≤5mm group. Sensitivity, positive predictive value (PPV), specificity, negative predictive value (NPV), and accuracy were calculated using statistical method for diagnostic studies, with conventional colonoscopy as a gold standard. Results Ninety and 61 polyps were found by CTC and conventional colonoscopy, respectively. The per-polyp sensitivity/PPV were 80.3%/55.6% in total, and 100%/92.9%, 93.8%/65.2%, and 68.8%/41.5% in the ≥10 mm group, 5-10 mm group, and ≤5mm group, respectively. The per-patient sensitivity, PPV, specificity, NPV, and accuracy were 97.1%, 89.5%, 42.9%, 75.0%, and 88.1%, respectively. Conclusion CTC can clearly reveal the morphology of colonic polyps and be used as a routine monitoring method for the clinical diagnosis of polyps.

Jumbo biopsy is useful for the diagnosis of colonic prolapsing mucosal polyps with diverticulosis

我们这里在 S 字形的冒号与憩室形成报导多重 prolapsing 粘膜息肉的一个案例。因为流血腹泻，一个 52 岁的人进入我们的医院。结肠镜检查和钡灌肠在 S 字形的冒号在他们的顶上与粘液显示出多重憩室，显著地变厚的粘膜褶层和水虫息似的损害。内视镜的 ultrasonography 出现了粘膜、粘膜下层的层变厚。几个内视镜的活体检视标本从水虫息似的损害被拿。组织学的检查揭示了仅仅长期的煽动性的房间渗入。以便获得明确的诊断，我们在获得知情同意以后为水虫息似的损害执行了内视镜的巨大的活体检视。揭示的组织学的检查在薄板 propria 标记淋巴细胞渗入，含铁血黄素存款和纤维肌性涂去，粘膜 prolapsing 的类似于那些的特征症候群。在 anti-diarrhetic 处理以后，临床的调查结果被改进。因此，巨大的活体检视为 prolapsing 粘膜息肉的诊断和处理是有用的。

DISTINGUISHING BETWEEN HYPERPLASTIC AND ADENOMATOUS POLYPS AND NORMAL COLONIC MUCOSA BY USING MULTIPHOTON LASER SCANNING MICROSCOPY

Precisely distinguishing between hyperplastic and adenomatous polyps and normal human colonic mucosa at the cellular level is of great medical significance.In this work,multiphoton laserscarming microscopy(MPLSM)was used to obtain the high.-contrast images and the morpho-logical characteristics from normal colonic mucosa,hyperplastic polyps and tubular adenoma.Byintegrating the length and area measurement tools and computing tool,we quantified thedifference of crypt morphology and the alteration of nuclei in normal and diseased human colonicmucosa.Our results demonstrated that the morphology of crypts had an obvious tendency tocystic dilatation or elongated in hyperplastic polyps and tubular adenoma.The cont ent andnumber of mucin droplets of the scattered goblet cells had a piecemeal reduction in hyperplastic polyps and a large decrease in tubular adenoma The nuclei of epithelial cells might be elongated and pseudostratified,but overt dysplasia was absent in hyperplastic polyps.Nevertheless,thenuclei showed enlarged,crowded,stratified and a rod-like structure,with loss of polarity intubular adenoma.These results suggest that MPLSM has the capacity to distinguish betweenhyperplastic and adenomat ous polyps and normal human colonic mucosa at the celular level.

Importance of the surrounding colonic mucosa in distinguishing between hyperplastic and adenomatous polyps during acetic acid chromoendoscopy

AIM: To examine the characteristics of colonic polyps, where it is difficult to distinguish adenomatous polyps from hyperplastic polyps, with the aid of acetic acid chromoendoscopy. METHODS: Acetic acid spray was applied to colonic polyps smaller than 10 mm before complete excision. Endoscopic images were taken before and 15-30 s after the acetic acid spray. Both pre-and post-sprayed images were shown to 16 examiners, who were asked to interpret the lesions as either hyperplastic or adenomatous polyps. Regression analysis was performed to determine which factors were most likely related to diagnostic accuracy. RESULTS: In 50 cases tested by the 16 examiners, the overall accuracy was 62.4% (499/800). Regression analysis demonstrated that surrounding colonic mucosa was the only factor that was significantly related to accuracy in discriminating adenomatous from hyperplastic polyps (P < 0.001). Accuracy was higher for polyps with linear surrounding colonic mucosa than for those with nodular surrounding colonic mucosa (P < 0.001), but was not related to the shape, location, or size of the polyp. CONCLUSION: The accuracy of predicting histology is significantly related to the pattern of colonic mucosa surrounding the polyp. Making a histological diagnosis of colon polyps merely by acetic acid spray is helpful for colon polyps with linear, regularly patterned surrounding colonic mucosa, and less so for those with nodular, irregularly patterned surrounding colonic mucosa.

Oncologic impact of colonic stents for obstructive left-sided colon cancer

Colonic stenting has had a significant positive impact on the management of obstructive left-sided colon cancer(OLCC) in terms of both palliative treatment and bridge-to-surgery(BTS). Notably, many studies have convincingly demonstrated the effectiveness of stenting as a BTS, resulting in improvements in shortterm outcomes and quality of life, safety, and efficacy in subsequent curative surgery, and increased cost-effectiveness, whereas the safety of chemotherapy after stenting and the long-term outcomes of stenting as a BTS are controversial. Several studies have suggested an increased risk of perforation in patients receiving bevacizumab chemotherapy after colonic stenting. In addition, several pathological analyses have suggested a negative oncological impact of colonic stenting. In contrast, many recent studies have demonstrated that colonic stenting for OLCC does not negatively impact the safety of chemotherapy or long-term oncological outcomes. The updated version of the European Society of Gastrointestinal Endoscopy guidelines released in 2020 included colonic stenting as a BTS for OLCC as a recommended treatment. It should be noted that the experience of endoscopists is involved in determining technical and clinical success rates and possibly oncological outcomes. This review discusses the positive and negative impacts of colonic stenting on OLCC treatment, particularly in terms of oncology.

Clinical characteristics of sentinel polyps and their correlation with proximal colon cancer: A retrospective observational study

BACKGROUND Colorectal cancer is a common malignant tumor of the digestive tract.The relationship between sentinel polyps(rectal polyps with proximal colon cancer)and proximal colon cancer has received extensive attention in recent years.However,there is still no clear conclusion regarding the relationship.AIM To investigate the clinical characteristics of sentinel polyps and their correlation with proximal colon cancer.METHODS A retrospective analysis of 2587 patients with rectal polyps from January 2006 to December 2017 was performed.According to whether or not proximal colon cancer was diagnosed,the patients were divided into either a sentinel polyp group(192 patients)or a pure rectal polyp group(2395 patients).The endoscopic features,clinicopathological features,therapeutic effects,and short-term prognosis were analyzed and compared between the two groups.RESULTS The mean age of patients in the sentinel polyp group was generally higher than that of the pure rectal polyp group,and the positivity rates of anemia,stool occult blood,and tumor markers of the sentinel polyp group were also significantly higher than those in the rectal polyp group(χ^2=90.56,P<0.01;χ^2=70.30,P<0.01;χ^2=92.80,P<0.01).The majority of the patients in the sentinel polyp group had multiple polyps,large polyps,adenomatous polyps,or sessile polyps(χ^2=195.96,P<0.01;χ^2=460.46,P<0.01;χ^2=94.69,P<0.01;χ^2=48.01,P<0.01).Most of the proximal colon cancers were Duke’s A and B stages in the sentinel polyp group.In the pure rectal polyp group,2203 patients underwent endoscopic treatment,and all of the patients were cured and discharged.In the sentinel polyp group,65 patients underwent radical operation,and 61 patients received endoscopic submucosal dissection or endoscopic mucosal resection.Additionally,21 patients were lost to follow-up after 6-12 mo,and the loss rate was 10.94%.A total of 63.16%of patients experienced remission without tumor recurrence or metastasis,33.33%of patients experienced tumors regression or improved symptoms,and the other 3.51%of the patients died.CONCLUSION If there are multiple,sessile,and adenomatous rectal polyps with a maximum diameter>1 cm,the possibility of the carcinogenesis of the polyps or of the proximal colon should be monitored closely.These patients should be followed in the short-term and should undergo a whole-colon examination.

Serrated polyps of the colon and rectum: Endoscopic features including image enhanced endoscopy

In this review, I outline the characteristic endoscopic findings of serrated lesions of the colorectum based on image enhanced endoscopy(IEE). Histopathologically, lesions with serrated structures are typically classified into the following three types based: hyperplastic polyps(HPs), traditional serrated adenomas(TSAs), and sessile serrated adenoma/polyps(SSA/Ps). Both HP and SSA/P often present as dark-green colors on auto fluorescence imaging(AFI) colonoscopy that are similar to the normal surrounding mucosa. In contrast, TSAs often have elevated shapes and present as magenta colors that are similar to the tubular adenomas. The superficial type of TSA also includes many lesions that present as magenta colors. When SSA/Ps are associated with cytological dysplasia, many lesions present with magenta colors, whereas lesions that are not associated with cytological dysplasia present with dark-green colors. When observed via narrow band imaging(NBI), many SSA/P include lesions with strong mucous adhesions. Because these lesions are observed with reddish mucous adhesions, we refer to them as "red cap sign" and place such signs among the typical findings of SSA/P. Because the dilatation of the pit in SSA/P is observed as a round/oval black dot on magnified observations, we refer to this finding as Ⅱ-dilatation pit(Ⅱ-D pit) and also positioned it as a characteristic finding of SSA/P. In contrast, dilatations of the capillary vessels surrounding the glands, such as those that occur in tubular adenoma, are not considered to be useful for differentiating HPs from SSA/Ps. However, in cases in which SSA/P is associated with cytological dysplasia, the dilatation of capillary vessels is observed in the same area. When submucosal layer invasion occurs in the same area, the blood flow presents with irregularities that are similar to those of common colorectal cancer at an early stage and disappears as the invasion proceeds deeply. The surface pattern of invasive cancer that is observed at the tumor surface is also likely to disappear. Based on the above results, we considered that the differentiations between HP and TSA, between TSA and SSA/P, and between HP and SSA/P might become easier due to the concomitant use of white light observation and IEE. We also concluded that AFI and NBI can be useful modalities for SSA/P lesions associated with cytological dysplasia.