Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology

Modifiable Failures in the Colorectal Cancer Screening Process and Their Association With Risk of Death

BACKGROUND & AIMS

Colorectal cancer (CRC) deaths occur when patients do not receive screening or have inadequate follow-up of abnormal results or when the screening test fails. We have few data on the contribution of each to CRC-associated deaths or factors associated with these events.

METHODS

We performed a retrospective cohort study of patients in the Kaiser Permanente Northern and Southern California systems (55-90 years old) who died of CRC from 2006 through 2012 and had ≥5 years of enrollment before diagnosis. We compared data from patients with those from a matched cohort of cancer-free patients in the same system. Receipt, results, indications, and follow-up of CRC tests in the 10-year period before diagnosis were obtained from electronic databases and chart audits.

RESULTS

Of 1750 CRC deaths, 75.9% (n = 1328) occurred in patients who were not up to date in screening and 24.1% (n = 422) occurred in patients who were up to date. Failure to screen was associated with fewer visits to primary care physicians. Of 3486 cancer-free patients, 44.6% were up to date in their screening. Patients who were up to date in their screening had a lower risk of CRC death (odds ratio, 0.38; 95% confidence interval, 0.33-0.44). Failure to screen, or failure to screen at appropriate intervals, occurred in a 67.8% of patients who died of CRC vs 53.2% of cancer-free patients; failure to follow-up on abnormal results occurred in 8.1% of patients who died of CRC vs 2.2% of cancer-free patients. CRC death was associated with higher odds of failure to screen or failure to screen at appropriate intervals (odds ratio, 2.40; 95% confidence interval, 2.07-2.77) and failure to follow-up on abnormal results (odds ratio, 7.26; 95% confidence interval, 5.26-10.03).

CONCLUSIONS

Being up to date on screening substantially decreases the risk of CRC death. In 2 health care systems with high rates of screening, most people who died of CRC had failures in the screening process that could be rectified, such as failure to follow-up on abnormal findings; these significantly increased the risk for CRC death.

From colorectal cancer pattern to the characterization of individuals at risk: Picture for genetic research in Latin America

Colorectal cancer (CRC) is one of the most common cancers in Latin America and the Caribbean, with the highest rates reported for Uruguay, Brazil and Argentina. We provide a global snapshot of the CRC patterns, how screening is performed, and compared/contrasted to the genetic profile of Lynch syndrome (LS) in the region. From the literature, we find that only nine (20%) of the Latin America and the Caribbean countries have developed guidelines for early detection of CRC, and also with a low adherence. We describe a genetic profile of LS, including a total of 2,685 suspected families, where confirmed LS ranged from 8% in Uruguay and Argentina to 60% in Peru. Among confirmed LS, path_MLH1 variants were most commonly identified in Peru (82%), Mexico (80%), Chile (60%), and path_MSH2/EPCAM variants were most frequently identified in Colombia (80%) and Argentina (47%). Path_MSH6 and path_PMS2 variants were less common, but they showed important presence in Brazil (15%) and Chile (10%), respectively. Important differences exist at identifying LS families in Latin American countries, where the spectrum of path_MLH1 and path_MSH2 variants are those most frequently identified. Our findings have an impact on the evaluation of the patients and their relatives at risk for LS, derived from the gene affected. Although the awareness of hereditary cancer and genetic testing has improved in the last decade, it is remains deficient, with 39%–80% of the families not being identified for LS among those who actually met both the clinical criteria for LS and showed MMR deficiency.

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study

OBJECTIVES

Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China.

METHODS

We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification.

RESULTS

Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r = 0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist's level of proficiency, number of colonoscopy operators and withdrawal time.

CONCLUSIONS

The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of > 60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6 min.

Implementing Colon Cancer Screening Guidelines Into the Primary Care Setting

Colon cancer is the second leading cause of all cancers deaths. Despite public awareness, many healthcare providers and patients remain uninformed about colon cancer screening options alternative to colonoscopy. Research supports the lack of providers' education and patient knowledge. At a clinic for veterans in Central Florida, 2 educational presentations were delivered to primary care providers (N = 46) on the clinical pathway for colon cancer screening options. A pilot study with a quantitative pretest-post-test design was used to evaluate differences between screening orders 3 months before and after the presentations. A 10-item survey on the usefulness of the educational information was also administered to providers. Results of a 1-way analysis of variance indicated no significant differences between the two 3-month periods. However, with exclusion of the lowest month, a significance level resulted of .087, 91.3% confidence level. Survey responses indicated a positive impact, with most answers ranging from agree to strongly agree. The study revealed that the educational clinical pathway contributed to providers' increased recommendations of screening options and the educational information was useful. Additional research is recommended on the effectiveness of education and providers' use of screening options for colon cancer for average-risk veterans in healthcare institutions.

Colonoscopy as Part of Pre-Transplant Work-Up in Successful Kidney Transplant Candidates: Single-Center Experience and Review of Literature

Background

Screening colonoscopy is not obligatory in kidney pre-transplant work-up guidelines. According to recommendations, only transplant recipients over age 50 years should be screened. The aim of this study was to characterize endoscopic findings revealed as part of pre-transplant work-up.

Material/Methods

We retrospectively reviewed pre-transplant work-up charts of 434 adult patients who received a cadaveric donor kidney transplantation (KT) from 2012 to 2015. Endoscopic findings analysis with age subgroup (<50 and ≥50) analysis were performed.

Results

Out of 434 of patients that underwent KT, 29% have had a colonoscopy. In 75.6% of those, pathologies were found. Hemorrhoids were found in 33% and polyps in 30.7% of patients. Adenoma detection rate (ADR) was 18.1% (67.5% distal predominance). Advanced ADR was 10.2% (distal predominance). Diverticulosis was found in 28.3% of patients and ulcerative colitis was found in 2.4%. In age subgroup analysis, ADR was higher in patients ≥50 years compared to those <50 years (21.6% vs. 4%; p=0.041).

Conclusions

Colonoscopy as part of pre-transplant work-up enables removal of precancerous lesions and management of benign findings. All candidates meeting criteria for the general population should be screened. Patients under age 50 years could also benefit from colonoscopy as part of the pre-transplant work-up. Therefore, we suggest that baseline colonoscopy should be included in pre-transplant work-up guidelines for all patients, regardless of age. However, further studies are needed to confirm this recommendation.

Clinical biomarkers for cancer recognition and prevention: A novel approach with optical measurements

Cancer is the most important cause of death worldwide, and early cancer detection is the most fundamental factor for efficacy of treatment, prognosis, and increasing survival rate. Over the years great effort has been devoted to discovering and testing new biomarkers that can improve its diagnosis, especially at an early stage. Here we report the potential usefulness of new, easily applicable, non-invasive and relatively low-cost clinical biomarkers, based on abnormalities of oral mucosa spectral reflectance and fractal geometry of the vascular networks in several different tissues, for identification of hereditary non-polyposis colorectal cancer carriers as well for detection of other tumors, even at an early stage. In the near future the methodology/technology of these procedures should be improved, thus making possible their applicability worldwide as screening tools for early recognition and prevention of cancer.

Processes of Change for Colonoscopy: Limited Support for Use Among Navigated Latinos

This study assessed the role of the processes of change (POC), a construct of the transtheoretical model, in colorectal cancer (CRC) screening among Latinos. Latinos participate in CRC screening less often and are diagnosed with CRC at a later stage than whites. POC items were administered to 344 English- and Spanish-speaking Latinos at average risk for CRC who had not had a colonoscopy in the past 5 years and received a colonoscopy referral. POC were measured at three timepoints: following informed consent (T1) at time of referral, 2 weeks prior to scheduled colonoscopy (T2), and 1 month after scheduled colonoscopy (T3). Participants received patient navigation as part of a randomized controlled trial to promote screening colonoscopy. POC scores were examined for changes during the course of the intervention, and logistic regression models assessed the relationship between POC scores and CRC screening adherence. Total POC scores decreased between T1 and T2 (p = 0.03) but were unchanged between T1 and T3. CRC screening adherence was not significantly associated with POC scores or change in POC scores over time. The POC instrument was not found useful for predicting colonoscopy adherence among Latinos in conjunction with patient navigation. Total POC scores did not increase during a patient navigation intervention despite high colonoscopy completion rates.

Chemoprevention of inflammation-related colorectal cancer by silymarin-, acetyl-11-keto-beta-boswellic acid-, curcumin- and maltodextrin-enriched dietetic formulation in animal model

On the basis of preliminary in vitro experience, we assessed whether an enriched nutritional formulation with estrogen receptor (ER)-beta agonist and anti-inflammatory properties may prevent inflammation-associated colorectal cancer (CRC) in an animal model. Study sample enclosed 110 C57BL/6J male mice. Forty underwent dietary supplement safety assessment (20 standard diet and 20 enriched formulation). Seventy were treated with azoxymethane (AOM)/dextran sulfate sodium and divided into two groups: 35 received standard diet and 35 enriched formulation (curcumin, boswellic acids, silymarin and maltodextrins). Miniature colonoscopy demonstrated colitis and solid lesion development in five mice/group 100 days after first AOM injection. Mice were killed after 10 days. In each group, four subgroups received intraperitoneal bromodeoxyuridine (BrdU) injection at 24th/48th/72nd/96th hour before killing. Anti-inflammatory effect and chemoprevention were evaluated by lesion number/size, histological inflammation/dysplasia/neoplasia assessment, pro-inflammatory cytokine messenger RNA (mRNA), ER-beta/ER-alpha/BrdU immunohistochemistry and TUNEL immunofluorescence. Standard formulation assumption was associated with colon shortening compared with enriched one (P = 0.04), which reduced solid lesion number and size (P < 0.001 for both), histological inflammation score (P = 0.04), pro-inflammatory cytokine mRNA expression (P < 0.001), number of low-grade dysplasia (LGD; P = 0.03) and high-grade dysplasia (P < 0.001) areas. CRC was observed in 69.6% in standard and 23.5% in enriched formulation assuming animals (P < 0.001). Enriched formulation induced lower ER-alpha expression in CRC (P < 0.001) and higher ER-beta expression in LGD (P < 0.001) being associated to higher epithelial turnover (BrdU; P<0.001) in normal mucosa and increased apoptosis in LGD and CRC (P < 0.001 for both). Our results are promising for a successful anti-inflammatory and chemopreventive effect of enriched formulation in CRC arising from inflamed tissue.

Screening Women Aged 50-59 for CRC Using Fecal Occult Blood Test Produces Outcomes Similar to Men Undergoing Screening Colonoscopy

BACKGROUND

Average-risk women aged 50-59 years have a lower incidence and mortality of colorectal cancer relative to age-matched men, calling into question the benefit of screening colonoscopy in this age group.

AIMS

We aimed to determine whether FOBT is an effective initial screening test in 50-59-year-old women.

METHODS

We conducted a cross-sectional study using a computerized endoscopic report generator. We identified 320,906 individuals who had average-risk screening colonoscopy and 32,369 who had colonoscopy for positive FOBT. The primary outcome was the positive predictive value (PPV) of FOBT for large polyp(s) greater than 9 mm, as a surrogate for advanced neoplasia.

RESULTS

Among patients aged 50-59 years undergoing screening colonoscopy, men were more likely than women to have large polyps (6.3 vs 4.2%, p < 0.0001). Black women undergoing screening colonoscopy had higher rates of large polyps compared to non-Black women. The PPV in FOBT-positive men aged 50-54 (11.5%) and 55-59 (14.4%) was higher than in women aged 50-54 (6.1%) and 55-59 (5.4%). Despite this lower PPV, women aged 50-54 with a positive FOBT had a similar rate of large polyps as 50-54-year-old men undergoing screening colonoscopy (6.1 vs 6.3%, p = 0.626).

CONCLUSIONS

CRC screening with FOBT identifies 50-59-year-old men and women with a higher risk of large polyps. Since younger women have a lower risk of large polyps than men, screening with FOBT in 50-59-year-old non-Black women could be an effective screening strategy, with outcomes similar to the use of screening colonoscopy in 50-59-year-old men.

Germline Pathogenic Variants in Homologous Recombination and DNA Repair Genes in an Asian Cohort of Young-Onset Colorectal Cancer

BACKGROUND

Growing evidence suggests a role for cancer susceptibility genes such as BRCA2 and PALB2 in young-onset colorectal cancers. Using a cohort of young colorectal cancer patients, we sought to identify and provide functional evidence for germline pathogenic variants of DNA repair genes not typically associated with colorectal cancer.

METHODS

We recruited 88 patients with young-onset colorectal cancers seen at a general oncology center. Whole-exome sequencing was performed to identify variants in DNA repair and colorectal cancer predisposition genes. Pathogenic BRCA2 and PALB2 variants were analyzed using immunoblot and immunofluorescence on patient-derived lymphoblastoid cells.

RESULTS

In general, our cohort displayed characteristic features of young-onset colorectal cancers. Most patients had left-sided tumors and were diagnosed at late stages. Four patients had familial adenomatous polyposis, as well as pathogenic APC variants. We identified 12 pathogenic variants evenly distributed between DNA repair and colorectal cancer predisposition genes. Six patients had pathogenic variants in colorectal cancer genes: APC (n = 4) and MUTYH monoallelic (n = 2). Another six had pathogenic variants in DNA repair genes: ATM (n = 1), BRCA2 (n = 1), PALB2 (n = 1), NTHL1 (n = 1), and WRN (n = 2). Pathogenic variants BRCA2 c.9154C>T and PALB2 c.1059delA showed deficient homologous recombination repair, evident from the impaired RAD51 nuclear localization and foci formation.

CONCLUSION

A substantial portion of pathogenic variants in young-onset colorectal cancer was found in DNA repair genes not previously associated with colorectal cancer. This may have implications for the management of patients. Further studies are needed to ascertain the enrichment of pathogenic DNA repair gene variants in colorectal cancers.

Significance of lymph node metastasis in the survival of stage IV colorectal cancer by hematogenous metastasis

Purpose

Although lymph node (LN) metastasis is an important prognostic marker of colorectal cancer (CRC), the effect of LN metastasis on the survival of stage IV CRC is debated yet.

Methods

LN status and survivals as well as clinicopathological features of synchronous stage IV CRC patients, operated for 8 years, were analyzed. Patients with hematogenous metastases were included only but those with peritoneal seeding or preoperative adjuvant therapy were not included.

Results

Total 850 patients were enrolled and 77 (9.1%) were without LN metastases (N0M1). N0M1 patients were older and have favorable pathological features including lower CEA than patients with LN metastasis (N + M1). The pathologically poor features accumulated with N stage progression within N + M1. N0M1 had better 5-year overall survival (OS) and disease free survival than N + M1. And 5-year OS's within N + M1 group were stratified and different according to N stage progression, although the effect of N stage progression is different according to curative resection or not. When compared with stage III, 5-year OS of N0M1 with curative resection was comparable to that of anyTN2aM0 and was better than anyTN2bM1.

Conclusion

LN metastasis is a significant prognostic factor in stage IV by hematogenous metastasis, too. N stage progression accumulates pathologically poor prognostic factors. However, the effect on survival of each N stage progression differs depending on curative resection or not of the hematogenous metastases.

Rates of Screening for Breast, Colorectal, and Cervical Cancers in Older People With Cognitive Impairment or Dementia: A Meta-Analysis

Purpose: Cancer screening may not be appropriate for some older people. We compare the likelihood of screening for colorectal, breast, and cervical cancers in older people with versus without cognitive impairment or dementia. Method: Systematic search of MEDLINE, Embase, and PsycINFO (to March 9, 2018) for articles reporting screening for colon, breast, and cervical cancers in patients with and without cognitive impairment or dementia. Studies were summarized quantitatively (random effects meta-analysis), according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: Studies reported data 1989-2008. The rate of screening for breast cancer by mammography was lower in women with cognitive impairment or dementia compared with those without (pooled odds ratio [OR] = 0.81, 95% confidence interval [CI] = [0.71, 0.91], p = .0007, six studies, N = 18,562). The rates of screening for cervical cancer by Pap smear (pooled OR = 0.88, 95% CI = [0.71, 1.08], p = 0.22, five studies, N = 409,131) and colorectal cancer by fecal occult blood test (pooled OR = 0.87, 95% CI = [0.55, 1.38], p = .55, two studies, N = 2,718) were not significantly lower in people with cognitive impairment or dementia. Conclusion: These historical rates provide a baseline for discussions around the need for more specific guidance to assist with decisions to discontinue screening. The study also identifies a gap in reported knowledge with respect to screening under current guidelines.

FECAL OCCULT BLOOD: A COMPARISON OF CHEMICAL AND IMMUNOCHEMICAL TESTS

BACKGROUND

Colorectal bleeding is a warning sign that may be identified by fecal occult blood testing. A positive fecal occult blood test result requires a subsequent colonoscopy, a costly and invasive examination. Therefore, the use of diagnostic tests with optimal sensitivity and specificity is warranted. In this study, we evaluated four different fecal occult blood tests in 176 patients undergoing colonoscopy and compared their results.

OBJECTIVE

To assess the sensitivity, specificity and predictive values of chemical and immunochemical fecal occult blood tests in patients undergoing colonoscopy and to evaluate the degree of concordance between the tests and colonoscopy.

METHODS

Patients with indications for colonoscopy also underwent fecal occult blood testing by chemical (toluidine test) and immunochemical methods, employing three commercially available kits. Based on the endoscopic findings, the colonoscopy was rated as positive or negative for colorectal bleeding. The degree of concordance between the fecal occult blood tests and the colonoscopy was evaluated by the kappa index.

RESULTS

Forty-four (25%) colonoscopies were categorized as positive for colorectal bleeding. The toluidine test presented lower concordance than the immunochemical tests, which showed moderate concordance with the colonoscopy. The toluidine test had the least sensitivity, specificity, and positive and negative predictive values.

CONCLUSION

The immunochemical fecal occult blood tests showed greater sensitivity, specificity and predictive values in detecting colorectal bleeding. The immunochemical tests had superior indexes of agreement with colonoscopy compared to the toluidine test.

Introduction of a colorectal cancer screening programme: results from a single-centre study

AIM

In 2014, a national colorectal cancer (CRC) screening programme was launched in the Netherlands. It is difficult to assess for the individual patients with CRC whether the oncological benefits of surgery will outweigh the morbidity of the procedure, especially in early lesions. This study compares patient and tumour characteristics between screen-detected and nonscreen-detected patients. Also, we present an overview of treatment options and clinical dilemmas when treating patients with early-stage colorectal disease.

METHOD

Between January 2014 and December 2016, all patients with nonmalignant polyps or CRC who were referred to the Department of Surgery of the Leiden University Medical Centre in the Netherlands were included. Baseline characteristics, type of treatment and short-term outcomes of patients with screen-detected and nonscreen-detected colorectal tumours were compared.

RESULTS

A total of 426 patients were included, of whom 240 (56.3%) were identified by screening. Nonscreen-detected patients more often had comorbidity (P = 0.03), the primary tumour was more often located in the rectum (P = 0.001) and there was a higher rate of metastatic disease (P < 0.001). Of 354 surgically treated patients, postoperative adverse events did not significantly differ between the two groups (P = 0.38). Of 46 patients with T1 CRC in the endoscopic resection specimen, 23 underwent surgical resection of whom only 30.4% had residual invasive disease at colectomy.

CONCLUSION

Despite differences in comorbidity, stage and surgical outcome of patients with screen-detected tumours compared to nonscreen-detected tumours were not significantly different. Considering its limited oncological benefits as well as the rate of adverse events, surgery for nonmalignant polyps and T1 CRC should be considered carefully.

Educational Video Followed by Retelling Bowel Preparation Process to Improve Colonoscopy Bowel Preparation Quality: A Prospective Nursing Intervention Study

Background

This study investigated the effect of a patient education video followed by retelling the process of bowel preparation on colonoscopy bowel preparation quality.

Material/Methods

This was a prospective, randomized, controlled clinical trial of outpatients undergoing colonoscopy. Patients were randomized (1: 1) to the video + retelling group or the control group. The primary endpoint was to assess the bowel preparation quality using the Ottawa Bowel Preparation Quality scale (Ottawa score). Risk factors associated with poor bowel preparation were also evaluated.

Result

The video + retelling group had a higher percentage of patients with adequate colonoscopy bowel preparation (Ottawa score <6) than the control group (P<0.001). Mean Ottawa total scores significantly differed between the control group and the video + retelling group (4.18±1.4 vs. 3.05±1.3, P<0.001). The video + retelling group showed superior cleanliness in the right, middle, and recto-sigmoid colon segments (all Ps <0.001). Logistic regression analysis revealed that male gender (OR=2.10, 95%CI: 1.098–4.018, P=0.025), diabetes mellitus (OR=2.830, 95%CI: 1.257–6.372, P=0.012), and no educational video followed by retelling bowel preparation process (OR=3.02, 95%CI: 1.731–5.270, P<0.001) were independently associated with poor bowel preparation.

Conclusions

Use of an educational video followed by asking patients to retell the process of bowel preparation after receiving regular instructions is a convenient and risk-free practice that enhances the compliance with bowel preparation guidance and improves bowel preparation quality.

Forensic luminol reaction for detecting fecal occult blood in experimental mice

Fecal occult blood (FOB) is a sign of gastrointestinal diseases, such as intestinal ulcers and colorectal cancer. In experimental animal studies, there is no standard method to detect FOB. Here, we present a simple protocol to detect FOB in mice, using the Luminol Reaction Experiment Kit^® that was originally designed to detect bloodstains at a crime scene in criminal forensics. To obtain positive control bloody feces, we used an indomethacin-induced intestinal ulcer model in mice. By mixing small pieces of feces with a luminol solution, the fecal solution emitted visible blue–white chemiluminescence in dark field when feces contained hemoglobin. We also established a method for semi-quantification of hemoglobin content in the fecal solution, using a luminometer. This method is simple, quick, economical and semi-quantitative, allowing researchers to detect FOB in experimental mice.

Potential of Aucklandia Lappa Decne Ethanolic Extract to Trigger Apoptosis of Human T47D and Hela Cells

Breast and cervical cancers are global health concerns and major cause of deaths among women. Current treatments such as chemotherapy are associated with several drawbacks that limit their effectiveness. Several anticancer remedies have been found with natural products in the past and the search continues for more examples. Cytotoxic natural compounds may have considerable benefits for cancer therapy either in potentiating the impact of chemotherapy or curtailment of harmful effects. Therefore, discovery and identification of new drugs for breast and cervical cancer treatment are of high priority. The present study addressed the potential role of the ALD (Aucklandia lappa Decne) in suppressing proliferation of T-47D, HeLa and HEp-2 cells in comparison with the non-cancer HCC1937 BL cell line. Treatment with an ALD extract of T-47D, HeLa, and HEp-2 cells resulted in reduction in cell viability in MMT assays. Furthermore, lyophilized ALD principally suppressed cancer cell line growth and proliferation through induction of either intrinsic or extrinsic apoptotic pathways as demonstrated by significantly suppressed release of LDH, and NO production in a dose-dependent manner, and activation of death receptors in T-47D and HeLa cells but not the HEp-2 cell line. Interestingly, lyophilized ALD significantly (p<0.005) repressed the growth of HEp-2 and T-47D cells after treatment for 48hrs while 24hrs treatment significantly suppressed T-47D and HeLa cells. We report for the first time that lyophilized ALD selectively influences apoptosis through alternative apoptotic pathways in both breast and cervical human cancer cells.

Colorectal Cancer: How Familiar Are Our Future Doctors with the Cancer of Tomorrow?

Background

Colorectal cancer (CRC) is one of the common cancers affecting both genders. Although the incidence of CRC is low in India there has been an increase in the past few decades.

Objective

To assess the awareness regarding colorectal cancer and its screening among medical students and interns.

Methods

This cross-sectional study was conducted among 290 participants (final year medical students and interns) from Kasturba Medical College, Mangalore. A pretested semistructured questionnaire was used to collect information. Data was analyzed using SPSS 17.0.

Results

Majority of participants had satisfactory knowledge regarding CRC. 38% of them scored excellently, 64.8% had good knowledge, and 5.2% scored poorly. Knowledge regarding CRC symptoms was good (95%). 92% of the participants were aware of risk factors of CRC. Only 49% of the participants identified FOBT as a screening tool and 30.7% participants knew that 50 years is the recommended age to begin CRC screening. Interns and international students had better knowledge than final year medical students and Indian students and this was found to be statistically significant.

Conclusion

There is a need to improve participant's knowledge regarding CRC screening although majority of them are aware of CRC symptoms and risk factors.

Identification of risk factors for neoplastic colonic polyps in young adults with bloody stool in comparison with those without symptom

BACKGROUND AND AIMS

The incidence and disease burden of colorectal cancer (CRC) in young adults were increasing. However, there was a dearth of advice on how to identify young population at risk for neoplastic colonic polyps (NCPs) and CRC. We aimed to identify risk factors for NCPs and CRC in young adults presenting with bloody stool.

METHODS

A total of 1496 subjects younger than 40 years old who underwent colonoscopy due to bloody stool from 2005 to 2014 were enrolled in this retrospective study as the study group, and 1481 age-matched and gender-matched asymptomatic subjects who underwent colonoscopy for health checkup from 2011 to 2016 were enrolled as the control group at a tertiary center hospital.

RESULTS

Multivariate analysis results showed that increasing age (odds ratio [OR] = 1.11, 95% confidence interval [CI]: 1.07-1.15, P < 0.001), higher body mass index (BMI) (OR = 1.07, 95%CI: 1.03-1.12, P = 0.001), diabetes mellitus (OR = 2.80, 95%CI: 1.06-7.42, P = 0.038), and positive family history of CRC (OR = 13.28, 95%CI: 5.70-30.97, P < 0.001) were identified as independent risk factors for NCPs in study group. The best cut-off values by receiver operating characteristic curve for age and BMI were 32 years old and 24.8 kg/m² , respectively. More risk factors were associated with the higher risk for NCPs (OR = 2.17 every increasing one risk factor, P < 0.001). In the control group, no independent risk factors were identified.

CONCLUSIONS

Adults aged ≤ 40 years with bloody stool who had increasing age (> 32 years old), higher BMI (> 24.8 kg/m² ), diabetes mellitus, and positive family history of CRC had a higher detection rate of NCPs and CRC.

Gastrointestinal cancer risk in patients with a family history of gastrointestinal cancer

Background/Aims

This study was performed to evaluate the relationship between family history of gastrointestinal (GI) cancers and incidence of any GI cancer in the Korean population.

Methods

Between January 2015 and July 2016, 711 GI cancer patients and 849 controls in 16 hospitals in Korea were enrolled. Personal medical histories, life styles, and family history of GI cancers were collected via questionnaire.

Results

There was a significant difference in the incidence of family history of GI cancer between GI cancer patients and controls (p=0.002). Patients with family history of GI cancer tended to be diagnosed as GI cancer at younger age than those without family history (p=0.016). The family members of GI cancer patients who were diagnosed before 50 years of age were more frequently diagnosed as GI cancer before the age of 50 years (p=0.017). After adjusting for major confounding factors, age (adjusted odds ratio [AOR] 1.065, 95% confidence interval [CI]; 1.053-1.076), male gender (AOR 2.270, 95% CI; 1.618-3.184), smoking (AOR 1.570, 95% CI; 1.130-2.182), and sibling's history of GI cancer (AOR 1.973, 95% CI; 1.246-3.126) remained independently associated with GI cancers.

Conclusions

GI cancer patients tended to have a first relative with a history of concordant GI cancer. Personal factors (old age and male) and lifestyle (smoking) contribute to the development of GI cancer, independently. Individuals with high risk for GI cancers may be advised to undergo screening at an earlier age.

A Simple and Novel Fecal Biomarker for Colorectal Cancer: Ratio of Fusobacterium Nucleatum to Probiotics Populations, Based on Their Antagonistic Effect

BACKGROUND

Gut microbial dysbiosis contributes to the development of colorectal cancer (CRC). We evaluated the utility of fecal bacterial biomarker candidates identified by our 16S rDNA sequencing analysis for CRC diagnosis.

METHODS

We measured the relative abundance of Fusobacterium nucleatum (Fn), Faecalibacterium prausnitzii (Fp), Bifidobacterium (Bb), and Lactobacillus (Lb) by quantitative PCR in fecal samples from 2 cohorts of 903 individuals. We evaluated and validated the diagnostic performance of these microbial ratios and investigated the antagonistic effect of Fn against 3 different indicator stains.

RESULTS

The microbial ratio of Fn to Bb (Fn/Bb) had a superior sensitivity of 84.6% and specificity of 92.3% in detecting CRC (area under the curve, AUC = 0.911). The combination of Fn/Bb and Fn/Fp improved the diagnostic value (AUC = 0.943). Moreover, the combination of Fn/Bb and Fn/Fp offered 60.0% specificity and 90.0% sensitivity in detecting stage I of CRC (AUC = 0.804). In particular, Fn was negatively correlated with Fp in the CRC group. The performance for CRC diagnosis was confirmed in the validation cohort II. The culture supernatant from Fn exhibited strong bactericidal activity against probiotics Fp and Bb strains.

CONCLUSIONS

This study found that Fn could play a role in microbiota dysbiosis via the secreted antagonistic substances against probiotics. Moreover, the ratio of Fn to the important probiotics Fp and Bb was identified as a valuable biomarker for screening early CRC.

Interval colorectal cancer: a challenging field in colorectal cancer

Accumulated evidence has shown that colonoscopy may not be a perfect tool in screening and reducing the incidence of the colorectal cancer (CRC), because interval CRC (I-CRC), a specific subgroup of CRCs, has been challenging the traditional detection technology in recent years. I-CRC is accounting for an increasing proportion in CRCs. However, the effective procedures to prevent and supervise I-CRC need to be explored. In this review, we summarized the incidence, causes, risk factors, characteristics and management of I-CRC. It would promote the awareness of the special value in the education and training for the gastroenterologists, which plays an important role in conquering CRC.

Predictors of non-adherence to colorectal cancer screening among immigrants to Ontario, Canada: a population-based study

Though colorectal cancer (CRC) screening rates have increased over time in Ontario, Canada, immigrants continue to have lower rates of screening. This study examines the association between non-adherence to CRC screening and immigration, socio-demographic, healthcare utilization, and primary care physician characteristics among immigrants to Ontario. This is a population-based retrospective cross-sectional study that uses healthcare administrative databases housed at the Institute for Clinical Evaluative Sciences. Our cohort comprised immigrants aged 60 to 74 years who lived in Ontario on March 31, 2015 and who had been eligible for the Ontario Health Insurance Plan for at least 10 years. The outcome was lack of adherence to CRC screening with any modality (fecal occult blood test, flexible sigmoidoscopy, colonoscopy) on March 31, 2015. Our cohort contained 182,949 immigrants. Overall 70,134 (38%) individuals were not adherent to screening. Risk of non-adherence to CRC screening was higher among immigrants who were from low (adjusted relative risk [ARR] 1.35, 95%CI 1.28-1.42) or low-middle (ARR 1.27, 95%CI 1.24-1.30, population-attributable risk [PAR] 9.8%) income countries and refugees (ARR 1.09, 95%CI 1.06-1.11). Compared to those from the United States, Australia, and New Zealand, immigrants from most other world regions, particularly Eastern Europe and Central Asia (ARR 1.28, 95%CI 1.21-1.37), had higher risks of non-adherence. Non-immigration factors such as low healthcare use and lack of primary care enrolment also increased the risk of non-adherence to screening. These findings can be used to inform future efforts to improve uptake of CRC screening among immigrant groups.

Japanese Practice Guidelines for Anal Disorders I. Hemorrhoids

The pathogenesis of hemorrhoids is a weakening of the anal cushion and spasm of the internal sphincter. Bowel habits and lifestyles can be risk factors for hemorrhoids. The prevalence of hemorrhoids can encompass 4 to 55% of the population. Symptoms include bleeding, pain, prolapsing, swelling, itching, and mucus soiling. The diagnosis of hemorrhoids requires taking a thorough history and conducting an anorectal examination. Goligher's classification, which indicates the degree of prolapsing with internal hemorrhoids, is useful for choosing treatment. Drug therapy for hemorrhoids is typically utilized for bleeding, pain, and swelling. Ligation and excision (LE) is considered for Grade III and IV internal and external hemorrhoids. Rubber band ligation is used to treat up to Grade III internal hemorrhoids. Phenol almond oil is effective for internal hemorrhoids up to Grade III, while aluminum potassium sulfate and tannic acid have shown efficacy in treating prolapsing in internal hemorrhoids at Grades II, III, and IV. Procedure for prolapse and hemorrhoids (PPH) is surgically effective for Grade III internal hemorrhoids; however, the long-term prognosis is not favorable, with high recurrence rates. Separating ligation is effective surgical treatment for internal/external hemorrhoids Grade III and Grade IV. The basic approach to thrombosed external hemorrhoids and incarcerated hemorrhoids is conservative treatment; however, in some acute or severe cases, surgical resection is considered. Comparing the different instruments used for hemorrhoid surgery, all reduce operating time, blood loss, post-operative pain, and length of time until the return to normal activity. They do, of course, increase the cost of the procedure.

I-scan optical enhancement for the in vivo prediction of diminutive colorectal polyp histology: Results from a prospective three-phased multicentre trial

Background and aims

Dye-less chromoendoscopy is an emerging technology for colorectal polyp characterization. Herein, we investigated whether the newly introduced I-scan optical enhancement (OE) can accurately predict polyp histology in vivo in real-time.

Methods

In this prospective three-phased study, 84 patients with 230 diminutive colorectal polyps were included. During the first two study phases, five endoscopists assessed whether analysis of polyp colour, surface and vascular pattern under i-scan OE can differentiate in vivo between adenomatous and hyperplastic polyps. Finally, junior and experienced endoscopists (JE, EE, each n = 4) not involved in the prior study phases made a post hoc diagnosis of polyp histology using a static i-scan OE image database. Histopathology was used as a gold-standard in all study phases.

Results

The overall accuracy of i-scan OE for histology prediction was 90% with a sensitivity, specificity, positive (PPV) and negative prediction value (NPV) of 91%, 90%, 86% and 94%, respectively. In high confidence predictions, the diagnostic accuracy increased to 93% with sensitivity, specificity, PPV and NPV of 94%, 91%, 89% and 96%. Colonoscopy surveillance intervals were predicted correctly in ≥ 90% of patients. In the post hoc analysis EE predicted polyp histology under i-scan OE with an overall accuracy of 91%. After a single training session, JE achieved a comparable diagnostic performance for predicting polyp histology with i-scan OE.

Conclusion

The histology of diminutive colorectal polyps can be accurately predicted with i-scan OE in vivo in real-time. Furthermore, polyp differentiation with i-scan OE appears to require only a short learning curve.

The Effect of Centrifugal Force in Quantification of Colorectal Cancer-Related mRNA in Plasma Using Targeted Sequencing

In our previous study, we detected the effects of centrifugal forces on plasma RNA quantification by quantitative reverse transcription PCR. The aims of this study were to perform targeted mRNA sequencing and data analysis in healthy donors' plasma prepared by two centrifugation protocols and to investigate the effects of centrifugal forces on plasma mRNA quality and quantity. Targeted mRNA sequencing was performed using a custom panel with 108 colorectal cancer-related genes in 18 healthy donors' plasma that prepared by (1) 3,500 g for 10 min at 4°C and (2) 1,600 g for 10 min at 4°C followed by 16,000 g for 10 min at 4°C. Results showed that plasma ribosomal RNA was detected in 16/18 (88.9%) 3,500 g and 6/18 (33.3%) 1,600 g followed by 16,000 g centrifuged plasma. For targeted sequencing, 75/108 (69.4%) and 86/108 (79.6%) genes were detected in 3,500 and 1,600 g followed by 16,000 g, respectively, while 16/108 (14.8%) genes were not detected in both centrifugations. Detailed analysis showed that 2 of 108 (1.85%) genes showed lower expressions in 3,500 g than in 1,600 g followed by 16,000 g. The median expressions of genes in 3,500 g were positively correlated with the expressions in 1,600 g followed by 16,000 g (R² = 0.9471, P < 0.0001, Spearman rank correlation). Meanwhile, plasma samples were not distinctively clustered based on centrifugal forces according to hierarchical clustering. Targeted mRNA sequencing and subsequent data analysis were performed in this study to investigate the effects of two different centrifugal forces that are commonly used in plasma collection. Our targeted sequencing results help to understand the centrifugal force effects on plasma mRNA, and these findings show that the centrifugation protocol for plasma mRNA research using targeted sequencing can be standardized which facilitates multicenter studies for comparison and quality assurance in the future.

Correlating colorectal cancer risk with field carcinogenesis progression using partial wave spectroscopic microscopy

Prior to the development of a localized cancerous tumor, diffuse molecular, and structural alterations occur throughout an organ due to genetic, environmental, and lifestyle factors. This process is known as field carcinogenesis. In this study, we used partial wave spectroscopic (PWS) microscopy to explore the progression of field carcinogenesis by measuring samples collected from 190 patients with a range of colonic history (no history, low-risk history, and high-risk history) and current colon health (healthy, nondiminutive adenomas (NDA; ≥5 mm and <10 mm), and advanced adenoma [AA; ≥10 mm, HGD, or >25% villous features]). The low-risk history groups include patients with a history of NDA. The high-risk history groups include patients with either a history of AA or colorectal cancer (CRC). PWS is a nanoscale-sensitive imaging technique which measures the organization of intracellular structure. Previous studies have shown that PWS is sensitive to changes in the higher-order (20-200 nm) chromatin topology that occur due to field carcinogenesis within histologically normal cells. The results of this study show that these nanoscale structural alterations are correlated with a patient's colonic history, which suggests that PWS can detect altered field carcinogenic signatures even in patients with negative colonoscopies. Furthermore, we developed a model to calculate the 5-year risk of developing CRC for each patient group. We found that our data fit this model remarkably well (R²  = 0.946). This correlation suggests that PWS could potentially be used to monitor CRC progression less invasively and in patients without adenomas, which opens PWS to many potential cancer care applications.

Appropriateness and yield of surveillance colonoscopy in first-degree relatives of colorectal cancer patients: A 5-year follow-up population-based study

BACKGROUND AND AIMS

There are few prospective data about the use of surveillance colonoscopy and the risk of recurrent neoplasia in first degree relatives (FDRs) of colorectal cancer (CRC) patients. We examined the use and yield of surveillance colonoscopy in a population-based screening program (Trentino, Italy) METHODS: 1252 FDRs have been included in this study. We calculated compliance (percentage of FDRs who underwent surveillance colonoscopy among those eligible), appropriateness of colonoscopy (appropriate if performed within 6 months of the guidelines recommended interval) and diagnostic yield for neoplasia. We compared these data with those of 765 individuals without a family history (FH) of CRC who underwent screening colonoscopy in the same period (controls).

RESULTS

Compliance and appropriateness were higher in FDRs than in controls (93.0% vs. 48.0%; p < 0.001; 59.6% vs. 18.8%; p < 0.0001, respectively). Younger age, female sex, FH of CRC and both non-advanced adenomas (nAA) and advanced adenomas (AA) at screening colonoscopy were predictors of appropriate surveillance. The cumulative incidence of nAA and AA was similar in FDRs and controls (31.7% and 4.9% in FDRs, including three invasive cancers; 32.4% and 5.8% in controls, respectively).

CONCLUSION

FH does not increase the risk of AA in a 5-year follow-up; appropriate surveillance practices in FDRs could be highly expected in an organized screening program.

Updates on Translational Research on Prevention of Polyps and Colorectal Cancer

Morbidity and mortality from colorectal cancer (CRC) can be effectively reduced through early detection and prevention. To date, strategies for managing CRC risk have focused primarily on secondary prevention, through screening asymptomatic individuals for colorectal neoplasia. In the United States, implementation of screening among individuals age ≥50 has led to not only decreased CRC-related mortality but also reduced CRC incidence through colonoscopic removal of precancerous polyps. In contrast to screening's endpoint of early detection, the goal of primary prevention of CRC is to arrest and/or reverse colorectal carcinogenesis. Observational studies and randomized clinical trials continue to examine effects of specific pharmacologic agents (chemoprevention) and dietary interventions on development of advanced colorectal neoplasia. This review will present an overview of strategies for primary and secondary prevention of CRC, including endoscopic, pharmacologic, and dietary interventions.

A structured light laser probe for gastrointestinal polyp size measurement: a preliminary comparative study

BACKGROUND AND STUDY AIMS

 Polyp size measurement is an important diagnostic step during gastrointestinal endoscopy, and is mainly performed by visual inspection. However, lack of depth perception and objective reference points are acknowledged factors contributing to measurement errors in polyp size. In this paper, we describe the proof-of-concept of a polyp measurement device based on structured light technology for future endoscopes.

PATIENTS AND METHODS

 Measurement accuracy, time, user confidence, and satisfaction were evaluated for polyp size assessment by (a) visual inspection, (b) open biopsy forceps of known size, (c) ruled snare, and (d) structured light probe, for a total of 392 independent polyp measurements in ex vivo porcine stomachs.

RESULTS

 Visual assessment resulted in a median estimation error of 2.2 mm, IQR = 2.6 mm. The proposed probe can reduce the error to 1.5 mm, IQR = 1.67 mm ( P  = 0.002, 95 %CI) and its performance was found to be statistically similar to using forceps for reference ( P  = 0.81, 95 %CI) or ruled snare ( P  = 0.99, 95 %CI), while not occluding the tool channel. Timing performance with the probe was measured to be on average 54.75 seconds per polyp. This was significantly slower than visual assessment (20.7 seconds per polyp, P  = 0.005, 95 %CI) but not significantly different from using a snare (68.5 seconds per polyp, P  = 0.73, 95 %CI). However, the probe's timing performance was partly due to lens cleaning problems in our preliminary design. Reported average satisfaction on a 0 - 10 range was highest for the proposed probe (7.92), visual assessment (7.01), and reference forceps (7.82), while significantly lower for snare users with a score of 4.42 ( P  = 0.035, 95 %CI).

CONCLUSIONS

 The common practice of visual assessment of polyp size was found to be significantly less accurate than tool-based assessment, but easy to carry out. The proposed technology offers an accuracy on par with using a reference tool or ruled snare with the same satisfaction levels of visual assessment and without occluding the tool channel. Further study will improve the design to reduce the operating time by integrating the probe within the scope tip.

Fecal immunochemical test for predicting mucosal healing in ulcerative colitis patients: A systematic review and meta-analysis

BACKGROUND AND AIM

Fecal immunochemical test (FIT) is a promising marker for assessment of inflammatory bowel disease activity. However, the utility of FIT for predicting mucosal healing (MH) of ulcerative colitis (UC) patients has yet to be clearly demonstrated. The objective of our study was to perform a diagnostic test accuracy test meta-analysis evaluating the diagnostic accuracy of FIT in predicting MH of UC patients.

METHODS

We systematically searched the databases from inception to November 2017 that evaluated MH in UC. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

Six studies comprising 625 UC patients were included in the meta-analysis. The pooled sensitivity and specificity values for predicting MH in UC were 0.77 (95% confidence interval [CI], 0.72-0.81) and 0.81 (95% CI, 0.76-0.85), respectively. The FIT level had a high rule-in value (positive likelihood ratio, 3.79; 95% CI, 2.85-5.03) and a moderate rule-out value (negative likelihood ratio, 0.26; 95% CI, 0.16-0.43) for predicting MH in UC. The results of the receiver operating characteristic curve analysis (area under the curve, 0.88; standard error of the mean, 0.02) and diagnostic odds ratio (18.08; 95% CI, 9.57-34.13) also revealed improved discrimination for identifying MH in UC with FIT concentration.

CONCLUSION

Our meta-analysis has found that FIT is a simple, reliable non-invasive marker for predicting MH in UC patients.

Applications of Colon Capsule Endoscopy

PURPOSE OF REVIEW

This is a review of colon capsule endoscopy (CCE) with a focus on its recent developments, technological improvements, and current and potential future indications.

RECENT FINDINGS

Based on the current literature, CCE II demonstrates comparable polyp detection rates as optical colonoscopy and CT colonography, and improved cost-effectiveness. The main limitation to patient acceptance is the requirement of a rigorous bowel preparation. Preliminary studies show good correlation between CCE and optical colonoscopy for assessment of colonic disease activity in inflammatory bowel disease (IBD). CCE II is currently FDA, approved as an adjunctive test in patients with prior incomplete colonoscopy, and in the evaluation of patients with suspected lower gastrointestinal bleeding. The test is approved in Europe as one of the options for average-risk colorectal cancer screening, and high-risk screening in patients with contraindications or unwilling to undergo colonoscopy. CCE has a potential role in the evaluation and monitoring of colonic disease activity in IBD. Future technological advances should focus on minimizing bowel preparation, improvement in reading times, and development of therapeutic capabilities. • With technological improvements, the second-generation colon capsule has a significantly higher sensitivity than the first-generation capsule for detection of colon polyps. • Colon capsule endoscopy has been approved in Europe as an option for average-risk colorectal cancer screening, and high-risk screening in patients with contraindications or unwilling to undergo colonoscopy. • Colon capsule endoscopy has received FDA approval as an option for colorectal cancer screening in patients with prior incomplete colonoscopy, and in evaluation of patients with suspected lower gastrointestinal bleeding. • Colon capsule endoscopy may have a role in evaluation and monitoring of inflammatory bowel disease. • Colon capsule endoscopy currently requires a bowel preparation that is more rigorous than colonoscopy.

Stool DNA Integrity Method for Colorectal Cancer Detection

Fluorescence long DNA (FL-DNA) is a non-invasive and simple-to-perform stool DNA test. This assay consists of a qualitative and quantitative real-time PCR (RT PCR) analysis. FL-DNA has great potential in colorectal cancer (CRC) lesions detection used alone or in combination with the standard CRC screening tool: immunochemical fecal occult blood test (iFOBT).

Cecal intubation rates in different eras of endoscopic technological development

Introduction

Colonoscopy plays a critical role in colorectal cancer (CRC) screening and has been widely regarded as the gold standard. Cecal intubation rate (CIR) is one of the well-defined quality indicators used to assess colonoscopy.

Aim

To assess the impact of new technologies on the quality of colonoscopy by assessing completion rates.

Material and methods

This was a dual-center study at the 2^nd Department of Surgery at Jagiellonian University Medical College and at the Specialist Center “Medicina” in Krakow, Poland. The CIR and cecal intubation time (CIT) in three different eras of technological advancement were determined. The study enrolled 27 463 patients who underwent colonoscopy as part of a national CRC screening program. The patients were divided into three groups: group I – 3408 patients examined between 2000 and 2003 (optical endoscopes); group II – 10 405 patients examined between 2004 and 2008 (standard electronic endoscopes); and group III – 13 650 patients examined between 2009 and 2014 (modern endoscopes).

Results

There were statistically significant differences in the CIR between successive eras. The CIR in group I (2000–2003) was 69.75%, in group II (2004–2008) was 92.32%, and in group III (2009–2014) was 95.17%. The mean CIT was significantly reduced in group III.

Conclusions

Our study shows that the technological innovation of novel endoscopy devices has a great influence on the effectiveness of the CRC screening program. The new era of endoscopic technological development has the potential to reduce examination-related patient discomfort, obviate the need for sedation and increase diagnostic yields.

Impact of feedback on adenoma detection rates: Outcomes of quality improvement program

BACKGROUND AND AIM

Feedback has been shown to improve performance in colonoscopy including adenoma detection rate (ADR). The frequency at which feedback should be given is unknown. As part of a quality improvement program, we sought to measure the outcome of providing quarterly and monthly feedback on colonoscopy quality measures.

METHODS

All screening colonoscopies performed at endoscopy unit at Mayo Clinic Arizona by gastroenterologists between October 2010 and December 2012 were reviewed. Quality indicators, including ADR, were extracted for each individual endoscopist, and feedback was provided. The study period was divided into four distinct groups: pre-intervention that served as baseline, quarterly feedback, monthly feedback, and post-intervention. Based on ADR, endoscopists were grouped into "low detectors" (≤ 25%), "average detectors" (26-35%), and "high detectors" (> 35%).

RESULTS

A total of 3420 screening colonoscopies were performed during the study period (555 patients during pre-intervention, 1209 patients during quarterly feedback, 599 during monthly feedback, and 1057 during the post-intervention period) by 16 gastroenterologists. The overall ADR for the group improved from 30.5% to 37.7% (P = 0.003). Compared with the pre-interventional period, all quality indicators measured significantly improved during the monthly feedback and post-intervention periods but not in the quarterly feedback period.

CONCLUSIONS

In our quality improvement program, monthly feedback significantly improved colonoscopy quality measures, including ADR, while quarterly feedback did not. The impact of the intervention was most prominent in the "low detectors" group. Results were durable up to 6 months following the intervention.

Risk of metachronous neoplasia on surveillance colonoscopy in young patients with colorectal neoplasia

BACKGROUND AND AIMS

Few prior reports exist that address the appropriate colonoscopy surveillance interval for individuals <50 years old. We compared the risk of metachronous neoplasia between younger (20-49 years) and older (50-54 years) cohorts.

METHODS

This multicenter retrospective cohort study compared the incidence of metachronous neoplasia in younger and older cohorts according to baseline risk stratification. Subjects were eligible if they underwent their first colonoscopy between June 2006 and May 2010 and had at least 1 or more surveillance colonoscopy up to June 2015.

RESULTS

Among a total of 10,477 subjects who underwent baseline colonoscopy, 9722 were eligible after excluding 755 subjects. Of those 9722 subjects, 43% underwent surveillance colonoscopy. In the baseline high-risk adenoma group (n = 840), the 3-year risk of metachronous advanced neoplasia was 10.7% in the younger patients on screening colonoscopy and 8.9% in the older patients (P > .1). In the baseline low-risk adenoma group (n = 1869), the 5-year risk of metachronous advanced neoplasia was 4.9% in the younger patients on screening colonoscopy and 5.1% in the older patients (P > .1). Similarly, in the baseline no neoplasia group (n = 7013), the 5-year risk of metachronous advanced neoplasia was 4.1% in the younger patients on screening colonoscopy and 5.6% in the older patients (P > .1).

CONCLUSIONS

Considering the similar risk of metachronous advanced neoplasia in younger and older individuals, we suggest a 3-year surveillance interval for high-risk adenoma and a 5-year surveillance interval for low-risk adenoma in young individuals without a strong family history.

Diagnostic yield is not influenced by the timing of screening endoscopy: morning versus afternoon

BACKGROUND

Previous studies have shown the colonoscopy quality affected by the endoscopist's fatigue. This study was aimed to evaluate this potential factor in a colorectal cancer-screening cohort of Chinese patients.

METHODS

The attendances at department of gastroenterology for colorectal cancer screening between 2013 and 2015 were retrospectively analyzed. The procedure time-of-day and hours elapse were recorded. The primary outcome was defined as adenoma detection rate (ADR).

RESULTS

A total of 1342 screening colonoscopies were performed by 19 gastroenterologists in the study. Detection rates were 7.7% for all polyps and 20.0% for adenomas. Time-of-day was not significantly associated with ADR. With time elapsing, the first climax for ADR was presented at 09:00-10:00, and persistently rose again after the lunch break. Significant inclined trend in ADR was noted for each hour blocks of a full day (p =  .0021).

CONCLUSIONS

The procedure time-of-day, morning versus afternoon, did not affect the diagnostic efficacy of screening endoscopy in Chinese patients.

Germline Genetic Features of Young Individuals With Colorectal Cancer

BACKGROUND & AIMS

The incidence of colorectal cancer (CRC) in individuals younger than 50 years is increasing. We sought to ascertain the proportion of young CRC cases associated with genetic predisposition.

METHODS

We performed a retrospective study of individuals diagnosed with CRC at an age younger than 50 years, evaluated by the clinical genetics service at a single tertiary care cancer center from 1998 through 2015. We collected data on patient histories, tumor phenotypes, and results of germline DNA sequencing. For subjects with uninformative clinical evaluations, germline DNA samples were (re)sequenced using a research-based next-generation sequencing multigene panel. The primary outcome was identification of a pathogenic germline mutation associated with cancer predisposition.

RESULTS

Of 430 young CRC cases, 111 (26%) had a first-degree relative with CRC. Forty-one of the subjects with CRC (10%) had tumors with histologic evidence for mismatch repair deficiency. Of 315 subjects who underwent clinical germline sequencing, 79 had mutations associated with a hereditary cancer syndrome and 21 had variants of uncertain significance. Fifty-six subjects had pathogenic variants associated with Lynch syndrome (25 with mutations in MSH2, 24 with mutations in MLH1, 5 with mutations in MSH6, and 2 with mutations in PMS2) and 10 subjects had pathogenic variants associated with familial adenomatous polyposis. Thirteen subjects had mutations in other cancer-associated genes (8 in MUTYH, 2 in SMAD4, 1 in BRCA1, 1 in TP53, and 1 in CHEK2), all identified through multigene panel tests. Among 117 patients with uninformative clinical evaluations, next-generation sequence analysis using a multigene panel detected actionable germline variants in 6 patients (5%). Only 43 of the 85 subjects with germline mutations associated with a hereditary cancer syndrome (51%) reported a CRC diagnosis in a first-degree relative.

CONCLUSIONS

Approximately 1 in 5 individuals diagnosed with CRC at age younger than 50 years carries a germline mutation associated with cancer; nearly half of these do not have clinical histories typically associated with the identified syndrome. Germline testing with multigene cancer panels should be considered for all young patients with CRC.

Systematic evaluation of supervised classifiers for fecal microbiota-based prediction of colorectal cancer

Predicting colorectal cancer (CRC) based on fecal microbiota presents a promising method for non-invasive screening of CRC, but the optimization of classification models remains an unaddressed question. The purpose of this study was to systematically evaluate the effectiveness of different supervised machine-learning models in predicting CRC in two independent eastern and western populations. The structures of intestinal microflora in feces in Chinese population (N = 141) were determined by 454 FLX pyrosequencing, and different supervised classifiers were employed to predict CRC based on fecal microbiota operational taxonomic unit (OTUs). As a result, Bayes Net and Random Forest displayed higher accuracies than other algorithms in both populations, although Bayes Net was found with a lower false negative rate than that of Random Forest. Gut microbiota-based prediction was more accurate than the standard fecal occult blood test (FOBT), and the combination of both approaches further improved the prediction accuracy. Moreover, when unclassified OTUs were used as input, the BayesDMNB text algorithm achieved higher accuracy in the Chinese population (AUC=0.994). Taken together, our results suggest that Bayes Net classification model combined with unclassified OTUs may present an accurate method for predicting CRC based on the compositions of gut microbiota.