Genotype-phenotype correlation of small-intestinal polyps on small-bowel capsule endoscopy in familial adenomatous polyposis.

BACKGROUND AND AIMS: In familial adenomatous polyposis (FAP), neoplastic lesions outside the colon have become increasingly important. The genotype-phenotype correlation has been established for duodenal polyps, and regular screening is recommended. However, this correlation remains unclear for small-intestinal lesions, except for reports on the relationship between their occurrence and Spigelman stage. Here, we used small-bowel capsule endoscopy (SBCE) to investigate the genotype-phenotype correlation of small-intestinal polyps in FAP. METHODS: The genotype-phenotype correlation of small-intestinal polyps was investigated in patients with FAP who underwent SBCE, Esophagogastroduodenoscopy (EGD), and adenomatous polyposis coli (APC) gene analysis. Of 64 patients with FAP who underwent SBCE, 41 were included in the final analysis, 4 did not undergo a complete small intestine examination, and 19 did not undergo genetic analysis. RESULTS: The prevalence (median number) of small-intestinal polyps by Spigelman stage was 26% (1.5), 0% (0), 44% (5), 60% (4), and 73% (25.5) for stages 0 to IV, respectively. Significantly more small-intestinal polyps were found in Spigelman stage III and IV groups than in the stage 0 group (P < .05). The APC variant was negative for 6 patients (15%), and the sites associated with more than 5 small-intestinal polyps were codons 278, 1062, 1114, 1281, 1307, 1314, and 1504. CONCLUSIONS: In FAP patients, SBCE surveillance is potentially recommended for patients with pathogenic variants in the APC gene at codons 278 and 1062 to 1504 or with Spigelman stage III or higher.

Endoscopic features of colorectal lymphoma according to histological type.

Background and Aim: This study aimed to investigate the relationship between the histological type of colorectal lymphoma and its endoscopic features. Methods: We retrospectively analyzed patients with primary colorectal lymphoma who were diagnosed using colonoscopy and biopsy specimens at the National Cancer Center Hospital, Tokyo, Japan. The lesions were macroscopically classified into the following types via colonoscopy: polypoid, ulcerative, multiple lymphomatous polyposis, diffuse, and mixed. Results: A total of 117 lesions were identified in 90 patients enrolled in this study. Of these, 59 (50%) were located in the ileocecal region, 23 (20%) in the rectum, 9 (8%) in the transverse colon, 8 (7%) in the sigmoid colon, 7 (6%) in the descending colon, and 4 (3%) in the ascending colon. Moreover, the most common histological subtypes were diffuse large B-cell lymphoma (DLBCL) in 39 patients (43%) and mantle cell lymphoma (MCL) in 23 patients (26%), followed by follicular lymphoma (FL; 17%), mucosa-associated lymphoid tissue (MALT) lymphoma (9%), peripheral T-cell lymphoma-NOS (2%), monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL; 2%), and Burkitt lymphoma (1%). More than half of the DLBCL (52%), MCL (52%), and MALT (56%) lymphomas were macroscopically classified as polypoid types. In contrast, FL lesions showed various macroscopic types. The majority of DLBCL (62%) and FL (78%) lesions were distributed in the ileocecal region. MCL lesions tended to be widely spread in various sites of the large intestine. Conclusions: Colorectal lymphomas showed macroscopically distinctive features depending on the histological type. Understanding the macroscopic classification of the lesions by colonoscopy and its distribution may be helpful in diagnosing the type of lymphoma and determining the malignant grade based on the histological types.

Association of Escherichia coli containing polyketide synthase in the gut microbiota with colorectal neoplasia in Japan.

Escherichia coli containing polyketide synthase in the gut microbiota (pks+ E coli) produce a polyketide-peptide genotoxin, colibactin, and are suspected to play a role in the development of colorectal neoplasia. To clarify the role of pks+ E coli in the early stage of tumorigenesis, we investigated whether the pks status of E coli was associated with the prevalence of colorectal neoplasia. This cross-sectional analysis of data from a prospective cohort in Izu Oshima, Japan included asymptomatic residents aged 40-79 years who underwent screening colonoscopy and provided a stool sample. We identified 543 participants with colorectal neoplasia (22 colorectal cancer and 521 adenoma) as cases and 425 participants with normal colon as controls. The pks status of E coli was assayed using stool DNA and specific primers that detected pks+ E coli. The proportion of pks+ E coli was 32.6% among cases and 30.8% among controls. Compared with those with pks- E coli, the odds ratio (OR) (95% confidence interval) for participants with pks+ E coli was 1.04 (0.77-1.41) after adjusting for potential confounders. No statistically significant associations were observed regardless of tumor site or number of colorectal adenoma lesions. However, stratified analyses revealed increased ORs among participants who consumed cereals over the median intake or vegetables under the median intake. Overall, we found no statistically significant association between pks+ E coli and the prevalence of colorectal adenoma lesions among this Japanese cohort. However, positive associations were suggested under certain intake levels of cereals or vegetables.

Risk Stratification Score Improves Sensitivity for Advanced Colorectal Neoplasia in Colorectal Cancer Screening: The Oshima Study Workgroup.

INTRODUCTION: Noninvasive colorectal cancer (CRC) screening methods with higher sensitivity for advanced colorectal neoplasia (ACN) than the fecal immunochemical test (FIT) alone are warranted. This study aimed to elucidate the diagnostic performance of a risk stratification score calculated using baseline individual characteristics and its combination with FIT for detecting ACN. METHODS: This cross-sectional analysis of data from a prospective cohort in Izu Oshima, Japan, included asymptomatic individuals age 40-79 years who underwent both 2-day quantitative FIT and screening colonoscopy. The 8-point risk score, calculated based on age, sex, CRC family history, body mass index, and smoking history, was assessed. Colonoscopy results were used as reference. RESULTS: Overall, 1,191 individuals were included, and 112 had ACN. The sensitivity and specificity of the 1-/2-day FIT (cutoff: 50-200 ng Hb/mL) for ACN were 17.9%-33.9% (4.9%-22.0% for right-sided ACN) and 91.8%-97.6%, respectively. The risk score's c-statistic for ACN was 0.66, and combining the score (cutoff: 5 points) with 1-/2-day FIT (cutoff: 50-200 ng Hb/mL) yielded a sensitivity and specificity for ACN of 46.4%-56.3% (43.9%-48.8% for right-sided ACN) and 76.6%-80.8%, respectively. The specificity of the risk score and FIT combination for all adenomatous lesions was 82.4%-86.4%. DISCUSSION: The 8-point risk score remarkably increased the sensitivity for ACN, particularly for right-sided ACN. Although the specificity decreased, it was still maintained at a relatively high level. The risk score and FIT combination has the potential to become a viable noninvasive CRC screening option.

Risk of metachronous neoplastic lesions during post-polypectomy surveillance in individuals with advanced colorectal neoplasia at initial screening colonoscopy.

BACKGROUND AND AIM: The evidence of associations between some types of advanced colorectal neoplasia (ACN) at baseline and the risk of metachronous neoplasia is inconsistent. This study aimed to elucidate the incidence of metachronous neoplasia during post-polypectomy surveillance in individuals with ACN at baseline and examine the risk factors for its high incidence. METHODS: Data from individuals who underwent endoscopic resection for ACN and received surveillance colonoscopy were analyzed. Data from individuals with no neoplastic lesions at baseline were used as reference. The incidence of metachronous ACN and clinically significant neoplasia (ACN and nonadvanced adenomas sized ≥ 5 mm) were evaluated. Risk factors for the higher incidence of these lesions were examined in individuals with ACN at baseline. RESULTS: During the median follow-up period of 61.8 months, metachronous ACN and nonadvanced adenomas sized ≥ 5 mm were detected in 9.6% and 32.4% of individuals with ACN at baseline (n = 136), respectively. The cumulative incidence of metachronous ACN and clinically significant neoplasia in individuals with ACN at baseline (3-year incidence: 5.5% and 16.9%, respectively) was higher than that in individuals with no neoplastic lesions at baseline (P < 0.01 for both). The presence of advanced histology at baseline, ≥ 5 neoplastic lesions at baseline, and family history of colorectal cancer were identified as risk factors for the higher incidence of clinically significant neoplasia. CONCLUSIONS: The relatively high incidence of metachronous neoplasia in individuals with ACN at baseline was confirmed; careful surveillance is required for these individuals, particularly in those with the risk factors.

Association between dietary sugar intake and colorectal adenoma among cancer screening examinees in Japan.

Although intake of highly sugary foods is considered to be a potential risk factor for colorectal cancer through hyperinsulinemia, the association of sugar intake and colorectal adenoma, a precursor lesion to most colorectal cancer, is poorly understood, particularly in Asian populations. We undertook a cross-sectional study in a Japanese population to investigate the association between dietary sugar intake and the prevalence of colorectal adenoma. Study subjects were selected from participants who underwent magnifying colonoscopy with dye spraying as part of a cancer screening program and who responded to a self-administered questionnaire before the colonoscopy. A total of 738 cases with colorectal adenoma and 697 controls were enrolled. Dietary intakes of glucose, fructose, galactose, sucrose, maltose, lactose, and total sugars (sum of these six mono- or disaccharides) were calculated from a food frequency questionnaire, and divided into quartiles based on the distribution among controls. Odds ratios and 95% confidence intervals of colorectal adenoma were estimated using unconditional logistic regression models, with adjustment for potential confounding factors. Total sugar intake was not significantly associated with the prevalence of colorectal adenoma (odds ratio for the highest intake group compared to reference group = 1.18; 95% confidence interval, 0.81-1.73; P for trend = .34). Furthermore, no statistically significant positive associations were observed for any of the six mono- or disaccharides. Findings were similar on additional analyses by site, size, and number of adenomas. Our findings do not support an association between high sugar intake and increased odds ratios of colorectal adenoma.

Prevalence of serrated lesions, risk factors, and their association with synchronous advanced colorectal neoplasia in asymptomatic screened individuals.

BACKGROUND AND AIM: Serrated lesions (SLs) have attracted attention as precursors of colorectal cancer (CRC). However, their prevalence, risk factors, and clinical significance have not been satisfactorily elucidated. This study used high-quality colonoscopy data to determine the prevalence of SLs and to identify their risk factors and relationship with synchronous advanced colorectal neoplasia (ACN) in asymptomatic screened individuals. METHODS: This study included data for 5218 individuals who underwent first-time screening colonoscopy by highly experienced endoscopists. The relationships between baseline characteristics and the presence of SLs and those between the presence of SLs and synchronous ACN were assessed using the chi-squared test and multivariate logistic regression. RESULTS: The proportions of individuals with SLs and right-sided SLs were 23.3% and 7.6%, respectively. Age, sex, family history of CRC, smoking, and body mass index were significantly related with the presence of SLs, and current smoking was most strongly associated with SLs (adjusted odds ratio [aOR] 2.6, 95% confidence interval [CI] 2.1-3.2). The aOR (95% CI) of the presence of SLs, SLs sized ≥ 10 mm, and right-sided SLs ≥ 5 mm for synchronous ACN was 1.4 (1.1-1.9), 3.5 (1.3-9.6), and 1.9 (1.0-3.8), respectively. The presence of left-sided SLs ≥ 10 mm (without right-sided SLs) was also significantly associated with ACN (aOR 8.1, 95% CI 2.0-33.7). CONCLUSIONS: The relatively high prevalence of SLs and risk factors in screened individuals were elucidated and the significant relationship between SLs, particularly SLs ≥ 10 mm and right-sided SLs ≥ 5 mm, and synchronous ACN was confirmed.

Family history of colorectal cancer and prevalence of advanced colorectal neoplasia in asymptomatic screened populations in different age groups.

BACKGROUND AND AIMS: The clinical significance of a family history (FH) of colorectal cancer (CRC) in first-degree relatives (FDRs) in CRC screening stratified by different age groups of screened individuals is not fully understood. We investigated the relationship between FH and the presence of advanced colorectal neoplasia (ACN) in screened individuals in different age groups. METHODS: Data from screened individuals aged 40 to 54 years (n = 2263) and 55 to 69 years (n = 2621) who underwent their first-ever screening colonoscopy were analyzed. The relationship between FH and ACN was examined, and a multivariate logistic regression analysis incorporating other baseline characteristics was performed. RESULTS: Among individuals aged 40 to 54 years, the prevalence of ACN was significantly higher in 249 individuals with affected FDRs than in those without (5.6% vs 1.6%; P < .01), with an adjusted odds ratio of 3.7 (95% confidence interval, 1.9-7.0; P < .01); the prevalence was particularly high in those having FDRs with CRC mortality (7.3%). Among individuals aged 55 to 69 years, the prevalence of ACN was not significantly different between 291 individuals with affected FDRs and those without (5.8% vs 5.8%; P = .95); however, individuals with 2 FDRs with CRC and mortality showed a high prevalence of ACN (17.4% and 42.9%, respectively). CONCLUSIONS: An FH of CRC in FDRs was associated with a higher prevalence of ACN in younger individuals, with a particularly high impact of FH of CRC mortality. In contrast, the impact of FH was weaker in older individuals except those having 2 FDRs with CRC or mortality.

Capsule Endoscopy after Hematopoietic Stem Cell Transplantation Can Predict Transplant-Related Mortality.

BACKGROUND AND OBJECTIVES: Allogenic hematopoietic stem cell transplantation (allo-SCT) is a curative therapy for hematological malignancies, but transplant-related mortality (TRM) remains a concern. This study aimed to determine the efficacy of capsule endoscopy (CE) by evaluating the correlation between inflammatory findings on CE and TRM. METHODS: The data of patients after allo-SCT were retrospectively collected. The association between findings on CE and TRM at 100 days from the CE was evaluated. RESULTS: Of the 94 patients included in the study, 47 showed inflammatory findings on CE. The findings were diagnosed as graft-versus-host disease (GVHD; n = 17), cytomegalovirus (CMV) infection (n = 14), and GVHD with CMV infection (n = 16). Of the 47 patients, 13 (28%) had TRM. Endoscopic diagnoses of these TRM cases were GVHD (n = 4), CMV infection (n = 0), and GVHD with CMV infection (n = 9). In contrast, in the remaining 47 patients who showed no inflammatory findings on CE, 2 patients (4%) had TRM. The proportion of TRM was higher in patients with inflammatory findings than in those without it (28 vs. 4%, p < 0.01). CONCLUSIONS: CE may predict TRM in patients who developed gastrointestinal symptoms after allo-SCT.

Feasibility of observational screening colonoscopy followed by deferred polypectomy.

BACKGROUND AND AIM: With the increasing necessity of colorectal cancer screening, observational screening colonoscopy during which only endoscopic observation and diagnosis is performed is worth consideration. However, whether detected lesions can be correctly identified at secondary colonoscopy performed for polypectomy is unclear. Further, whether new neoplastic lesions can be detected at secondary colonoscopy has not been fully examined. This study was performed to investigate the detectability of adenomatous polyps and advanced colorectal neoplasia (ACN) at secondary colonoscopy. METHODS: Data were analyzed from individuals who underwent initial observational screening colonoscopy followed by secondary colonoscopy for polypectomy. The proportion of correct detection at secondary colonoscopy of the lesions detected at initial colonoscopy was assessed. The number and characteristics of lesions that were newly detected at secondary colonoscopy were also evaluated. RESULTS: Data of 587 individuals were assessed. Among the 1 331 lesions detected at the initial colonoscopy, 1 151 (86.5%) were properly detected at the secondary colonoscopy. The proportions of correct detection at the secondary colonoscopy for ACN, non-advanced adenomas sized 5 to 9 mm, and non-advanced adenomas sized 1 to 4 mm were 100%, 95.4%, and 70.3%, respectively. In total, 175 adenomatous polyps and ACNs were newly detected at secondary colonoscopy in 112 individuals (19.1% of all individuals). Most of the lesions (165 lesions, 94.3%) were non-advanced adenomas, while advanced adenomas (5.7%) were also found. CONCLUSION: Screening by observational colonoscopy followed by deferred polypectomy is a feasible option in terms of lesion detectability, particularly when lesions sized ≥ 5 mm are the treatment target.

Incidence of Advanced Colorectal Neoplasia in Individuals With Untreated Diminutive Colorectal Adenomas Diagnosed by Magnifying Image-Enhanced Endoscopy.

OBJECTIVES: Because of the increasing number of detected diminutive colorectal adenomas, the "diagnose-and-do-not-resect" approach has recently attracted attention as an alternative to resection. We evaluated the cumulative incidence of advanced colorectal neoplasia (ACN) in individuals with untreated diminutive adenomas and compared this incidence in individuals without adenomas. METHODS: Data from 1,378 individuals who underwent first screening colonoscopy (CS) and at least one follow-up CS without polypectomy were analyzed. Patients with no adenomas or with only nonadvanced diminutive adenomas (<5 mm) diagnosed by magnifying image-enhanced endoscopy were scheduled to undergo a follow-up CS within 5 years after the initial CS without treatment. The participants were divided into 2 groups: those with untreated diminutive adenomas (group A) and those with no adenomas (group B). The cumulative incidence of ACN and the hazard ratio were assessed using Gray's test and the Fine and Gray model. RESULTS: During the median follow-up period of 60.9 months, 21 ACNs were detected. The 5-year cumulative incidences of ACN in group A (n = 361) and group B (n = 1,017) were 1.4% (95% confidence interval [CI]: 0.5-3.4) and 0.8% (95% CI: 0.3-1.7), respectively, without a statistically significant difference (P = 0.23). No ACNs developed from unresected adenomas. The smoking status was significantly associated with the incidence of ACN, and the hazard ratio for ACN in group A vs group B adjusted for smoking status was 1.43 (95% CI: 0.52-3.90; P = 0.48). DISCUSSION: The low 5-year cumulative incidence of ACN suggests the potential to adopt the "diagnose-and-do-not-resect" strategy as an alternative option for diminutive adenomas not requiring excessive surveillance.

A scoring model for predicting advanced colorectal neoplasia in a screened population of asymptomatic Japanese individuals.

BACKGROUND: Risk stratification of screened populations could help improve colorectal cancer (CRC) screening. Use of the modified Asia-Pacific Colorectal Screening (APCS) score has been proposed in the Asia-Pacific region. This study was performed to build a new useful scoring model for CRC screening. METHODS: Data were reviewed from 5218 asymptomatic Japanese individuals who underwent their first screening colonoscopy. Multivariate logistic regression was used to investigate risk factors for advanced colorectal neoplasia (ACN), and a new scoring model for the prediction of ACN was developed based on the results. The discriminatory capability of the new model and the modified APCS score were assessed and compared. Internal validation was also performed. RESULTS: ACN was detected in 225 participants. An 8-point scoring model for the prediction of ACN was developed using five independent risk factors for ACN (male sex, higher age, presence of two or more first-degree relatives with CRC, body mass index of > 22.5 kg/m2, and smoking history of > 18.5 pack-years). The prevalence of ACN was 1.6% (34/2172), 5.3% (127/2419), and 10.2% (64/627) in participants with scores of < 3, ≥ 3 to < 5, and ≥ 5, respectively. The c-statistic of the scoring model was 0.70 (95% confidence interval, 0.67-0.73) in both the development and internal validation sets, and this value was higher than that of the modified APCS score [0.68 (95% confidence interval, 0.65-0.71), P = 0.03]. CONCLUSIONS: We built a new simple scoring model for prediction of ACN in a Japanese population that could stratify the screened population into low-, moderate-, and high-risk groups.

Genetic and epigenetic alterations in normal tissues have differential impacts on cancer risk among tissues.

Genetic and epigenetic alterations are both involved in carcinogenesis, and their low-level accumulation in normal tissues constitutes cancer risk. However, their relative importance has never been examined, as measurement of low-level mutations has been difficult. Here, we measured low-level accumulations of genetic and epigenetic alterations in normal tissues with low, intermediate, and high cancer risk and analyzed their relative effects on cancer risk in the esophagus and stomach. Accumulation of genetic alterations, estimated as a frequency of rare base substitution mutations, significantly increased according to cancer risk in esophageal mucosae, but not in gastric mucosae. The mutation patterns reflected the exposure to lifestyle risk factors. In contrast, the accumulation of epigenetic alterations, measured as DNA methylation levels of marker genes, significantly increased according to cancer risk in both tissues. Patients with cancer (high-risk individuals) were precisely discriminated from healthy individuals with exposure to risk factors (intermediate-risk individuals) by a combination of alterations in the esophagus (odds ratio, 18.2; 95% confidence interval, 3.69-89.9) and by only epigenetic alterations in the stomach (odds ratio, 7.67; 95% confidence interval, 2.52-23.3). The relative importance of epigenetic alterations upon genetic alterations was 1.04 in the esophagus and 2.31 in the stomach. The differential impacts among tissues will be critically important for effective cancer prevention and precision cancer risk diagnosis.

Performance of 18-fluoro-2-deoxyglucose positron emission tomography for esophageal cancer screening.

AIM: To evaluate the performance of 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) for esophageal cancer (EC) screening. METHODS: We retrospectively analyzed the data of consecutive asymptomatic individuals who underwent FDG-PET and esophagogastroduodenoscopy (EGD) simultaneously for cancer screening at our institution from February 2004 to March 2013. In total, 14790 FDG-PET and EGD procedures performed for 8468 individuals were included in this study, and the performance of FDG-PET for EC screening was assessed by comparing the results of FDG-PET and EGD, considering the latter as the reference. RESULTS: Thirty-two EC lesions were detected in 28 individuals (31 squamous cell carcinomas and 1 adenocarcinoma). The median tumor size was 12.5 mm, and the depths of the lesions were as follows: Tis (n = 12), T1a (n = 15), and T1b (n = 5). Among the 14790 FDG-PET procedures, 51 examinations (0.3%) showed positive findings in the esophagus; only 1 was a true-positive finding. The screen sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET for ECs were 3.6% (95%CI: 0.1-18.3), 99.7% (95%CI: 99.6-99.7), 2.0% (95%CI: 0.0-10.4), and 99.8% (95%CI: 99.7-99.9), respectively. Of the 50 FDG-PET false-positive cases, 31 were observed in the lower esophagus, and gastroesophageal reflux disease was observed in 17 of these 31 cases. CONCLUSION: This study is the first to clarify the FDG-PET performance for EC screening. Based on the low screen sensitivity, FDG-PET is considered to be difficult to use as a screening modality for ECs.

Regional colorectal cancer screening program using colonoscopy on an island: a prospective Nii-jima study.

Objective: Colorectal cancer screening program using fecal immunochemical test had been conducted on an isolated island named Nii-jima. However, the participation rate of the program had been approximately 12%, which was lower than average level of Japan. This study aimed to evaluate the participation rate, safety and efficacy of a colorectal cancer screening program using colonoscopy on the island. Methods: Educational campaigns were actively conducted every month using information bulletins and special propaganda pamphlets. The primary recommended modality was colonoscopy, followed by fecal immunochemical test. The participants of this program were 1671 individuals aged 40­79 years (men, 819; women, 852). Results: A total of 789 (47.2%) individuals provided consent for this screening program, and 89.2% (704/789) of participants chose colonoscopy as the primary screening procedure. The completion rate of total colonoscopy was 99.7%, and there was no complication during this program. Detection rates of invasive cancer, intramucosal cancer, advanced neoplasia and any adenoma were 0.9% (n = 6), 2.4% (n = 17), 11.8% (n = 83) and 50.0% (n = 352), respectively. The adenoma detection rate and incidence of advanced neoplasia were significantly higher in men than in women in all age groups. Conclusions: The colorectal cancer screening program using colonoscopy that was conducted on an island achieved considerably higher participation rate than the conventional screening program using fecal immunochemical test. Completion rate and safety of screening colonoscopy were excellent during this program.

Sensitivity of 2-[18F]fluoro-2-deoxyglucose positron emission tomography for advanced colorectal neoplasms: a large-scale analysis of 7505 asymptomatic screening individuals.

BACKGROUND: The sensitivity of 2-[18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) for advanced colorectal neoplasms among healthy subjects is not yet fully understood. The present study aimed to clarify the sensitivity by analyzing large-scale data from an asymptomatic screening population. METHODS: A total of 7505 asymptomatic screenees who underwent both FDG-PET and colonoscopy at our Cancer Screening Division between February 2004 and March 2013 were analyzed. FDG-PET and colonoscopy were performed on consecutive days, and each examination was interpreted in a blinded fashion. The results of the two examinations were compared for each of the divided six colonic segments, with those from colonoscopy being set as the reference. The relationships between the sensitivity of FDG-PET and clinicopathological features of advanced neoplasms were also evaluated. RESULTS: Two hundred ninety-one advanced neoplasms, including 24 invasive cancers, were detected in 262 individuals. Thirteen advanced neoplasms (advanced adenomas) were excluded from the analysis because of the coexistence of lesions in the same colonic segment. The sensitivity, specificity, and positive and negative predictive values of FDG-PET for advanced neoplasms were 16.9 % [95 % confidence interval (CI) 12.7-21.8 %], 99.3 % (95 % CI 99.2-99.4 %), 13.5 % (95 % CI 10.1-17.6 %), and 99.4 % (95 % CI 99.3-99.5 %), respectively. The sensitivity was lower for lesions with less advanced histological grade, of smaller size, and flat-type morphology, and for those located in the proximal part of the colon. CONCLUSIONS: FDG-PET is believed to be difficult to use as a primary screening tool in population-based colorectal cancer screening because of its low sensitivity for advanced neoplasms. Even when it is used in opportunistic cancer screening, the limit of its sensitivity should be considered.

Assessment of an electronic learning system for colon capsule endoscopy: a pilot study.

BACKGROUND: Training for colon capsule endoscopy (CCE) procedures is currently performed as a lecture and hands-on seminar. The aims of this pilot study were to assess the utility of an electronic learning system for CCE (ELCCE) designed for the Japanese Association for Capsule Endoscopy using an objective scoring engine, and to evaluate the efficacy of ELCCE on the acquisition of CCE reading competence. METHODS: ELCCE is an Internet-based learning system with the following steps: step 1, introduction; step 2, CCE reading competence assessment test (CCAT), which evaluates the competence of CCE reading prior to training; step 3, learning reading theory; step 4, training with guidance; step 5, training without guidance; step 6, final assessment; and step 7, the same as step 2. The CCAT, step 5 and step 6 were scored automatically according to: lesion detection, diagnosis (location, size, shape of lesion), management recommendations, and quality of view. Ten trainee endoscopists were initially recruited (cohort 1), followed by a validating cohort of 11 trainee endoscopists (cohort 2). RESULTS: All but one participant finished ELCCE training within 7 weeks. In step 6, accuracy ranged from 53 to 98 % and was not impacted by step 2 pretest scores. The average CCAT scores significantly increased between step 2 pretest and step 7 in both cohorts, from 42 ± 18 % to 79 ± 15 % in cohort 1 (p = 0.0004), and from 52 ± 15 % to 79 ± 14 % in cohort 2 (p = 0.0003). CONCLUSIONS: ELCCE is useful and effective for improving CCE reading competence.

Surveillance using capsule endoscopy is safe in post-colectomy patients with familial adenomatous polyposis: a prospective Japanese study.

The utility of capsule endoscopy (CE) for the surveillance of small intestinal lesions in familial adenomatous polyposis (FAP) patients has been reported. However, few studies have investigated the safety of CE in FAP patients who have undergone colon surgery. We aimed to assess the safety of surveillance CE in post-colectomy FAP patients and the endoscopic findings associated with small intestinal lesions. We assessed the safety of CE surveillance of small intestinal lesions in 41 FAP patients who had undergone colectomies. Forty-two CEs were performed in 41 patients at our facility from April 2012 to July 2014. CE was conducted safely and none of the capsules were retained, despite the inclusion of patients who had undergone several abdominal surgeries previously. Thirty-nine out of 42 capsules (93 %) were retrieved within the examination timeframe; hence, the retrieval rate was favorable. The findings from this study indicate that surveillance CE can be safely conducted in post-colectomy FAP patients.