Prospective Colonoscopy Study Research Articles

Validity of the Asia-Pacific Colorectal Screening Score as a Risk Prediction Score for Advanced Colorectal Neoplasia in Chinese Symptomatic Subjects: A Prospective Colonoscopy Study

Validity of the Asia-Pacific Colorectal Screening Score as a Risk Prediction Score for Advanced Colorectal Neoplasia in Chinese Symptomatic Subjects: A Prospective Colonoscopy Study

Tailoring choice between colonoscopy versus sigmoidoscopy for population-based colorectal cancer screening in Chinese patients: a prospective colonoscopy study

BackgroundThe rising incidence and mortality of colorectal cancer (CRC) in China highlights the pressing need for population-based screening. Flexible sigmoidoscopy (FS) is becoming increasingly popular as a primary screening tool; and in many regions of China, colonoscopy capacity is limited. However, FS is preferred for patients with a low risk of advanced proximal neoplasia (APN; ie, higher numbers needed to screen [NNS], since the test predominantly examines the distal colon. Tailoring endoscopic screening based on the risk of APN is necessary, especially in resource-deprived regions. Since old age and female sex are two important CRC risk factors, we hypothesised that younger Chinese women aged 50–59 years had a significantly lower APN rate than did older Chinese men. MethodsIn 2013–15, we recruited 5833 asymptomatic participants aged 50–75 years who were registered for CRC screening in a large hospital-based endoscopy unit in Shanghai, China. Those with poor bowel preparation and whose colonoscopy failed caecal intubation were excluded. All polyps were removed as deemed appropriate and examined by histopathologists who were masked to the patients' data. We used χ2 test to compare APN among different age and gender groups. The respective NNS were evaluated. Institutional ethics board approval was obtained by the hospital while informed consent was sought before subject recruitment. FindingsFor men, the prevalence of APN was 2·5% (31/1264, 95% CI 1·7–3·5) in those aged 50–59 years, 4·1% (30/735, 2·9–5·8) in those aged 60–64 years, and 5·2% (38/727, 3·8–7·1) in those aged 65–75 years. In women, the APN prevalence was 0·7% (11/1607, 0·4–1·2) in those aged 50–59 years, 0·8% (6/766,0·3–1·8) in those aged 60–64 years, 4·8% (35/734,3·4–6·6) in those aged 65–75 years in those aged 66 years or older (p<0·001). The NNS by colonoscopy to detect one APN was 124 (95% CI 80–270) women aged 50–59 years and 96 (57–310) women aged 60–64, compared with the significantly lower NNS in other age or gender subgroups (range 14–58; p<0·001). InterpretationThese findings supported the application of sigmoidoscopy for CRC screening among female individuals younger than 65 years, given their low risk of APN and high NNS. Colonoscopy could be favoured for Chinese individuals aged 65 years or older. The feasibility and cost-effectiveness of this simple, tailored screening strategy in different Chinese populations should be further examined. FundingNone.

Risk of Colorectal Neoplasia in Individuals With Self-Reported Family History: A Prospective Colonoscopy Study from 16 Asia-Pacific Regions.

We tested the hypothesis that the risk of colorectal cancer (CRC), advanced colorectal neoplasia (ACN), and colorectal adenoma among screening participants with different first-degree relatives (FDRs) affected by CRC was similar. A multi-center, prospective colonoscopy study involving 16 Asia-Pacific regions was performed from 2008 to 2015. Consecutive self-referred CRC screening participants aged 40-70 years were recruited, and each subject received one direct optical colonoscopy. The prevalence of CRC, ACN, and colorectal adenoma was compared among subjects with different FDRs affected using Pearson's χ2 tests. Binary logistic regression analyses were performed to evaluate the risk of these lesions, controlling for recognized risk factors including age, gender, smoking habits, alcohol drinking, body mass index, and the presence of diabetes mellitus. Among 11,797 asymptomatic subjects, the prevalence of CRC was 0.6% (none: 0.6%; siblings: 1.1%; mother: 0.5%; father: 1.2%; ≥2 members: 3.1%, P<0.001), that of ACN was 6.5% (none: 6.1%; siblings: 8.3%; mother: 7.7%; father: 8.7%; ≥2 members: 9.3%, P<0.001), and that of colorectal adenoma was 29.3% (none: 28.6%; siblings: 33.5%; mother: 31.8%; father: 31.1%; ≥2 members: 38.1%, P<0.001). In multivariate regression analyses, subjects with at least one FDR affected were significantly more likely to have CRC (adjusted odds ratio (AOR)=2.02-7.89), ACN (AOR=1.55-2.06), and colorectal adenoma (AOR=1.31-1.92) than those without a family history. The risk of CRC (AOR=0.90, 95% confidence interval (CI) 0.34-2.35, P=0.830), ACN (AOR=1.07, 95% CI 0.75-1.52, P=0.714), and colorectal adenoma (AOR=0.96, 95% CI 0.78-1.19, P=0.718) in subjects with either parent affected was similar to that of subjects with their siblings affected. The risk of colorectal neoplasia was similar among subjects with different FDRs affected. These findings do not support the need to discriminate proband identity in screening participants with affected FDRs when their risks of colorectal neoplasia were estimated.

Validation of a risk prediction score for proximal neoplasia in colorectal cancer screening: a prospective colonoscopy study.

This study developed a clinical scoring system to predict the risks of PN among screening participants for colorectal cancer. We recruited 5,789 Chinese asymptomatic screening participants who received colonoscopy in Hong Kong (2008–2014). From random sampling of 2,000 participants, the independent risk factors were evaluated for PN using binary regression analysis. The odds ratios for significant risk factors were used to develop a scoring system, with scores stratified into ‘average risk’ (AR):0–2 and ‘high risk’ (HR):3–5. The other 3,789 subjects formed an independent validation cohort. Each participant received a score calculated based on their risk factors. The performance of the scoring system was evaluated. The proportion of PN in the derivation and validation cohorts was 12.6% and 12.9%, respectively. Based on age, gender, family history, body mass index and self-reported ischaemic heart disease, 85.0% and 15.0% in the validation cohort were classified as AR and HR, respectively. Their prevalence of PN was 12.0% and 18.1%, respectively. Participants in the HR group had 1.51-fold (95% CI = 1.24–1.84, p < 0.001) higher risk of PN than the AR group. The overall c-statistics of the prediction model was 0.71(0.02). The scoring system is useful in predicting the risk of PN to prioritize patients for colonoscopy.

The discriminatory capability of existing scores to predict advanced colorectal neoplasia: a prospective colonoscopy study of 5,899 screening participants.

We evaluated the performance of seven existing risk scoring systems in predicting advanced colorectal neoplasia in an asymptomatic Chinese cohort. We prospectively recruited 5,899 Chinese subjects aged 50–70 years in a colonoscopy screening programme(2008–2014). Scoring systems under evaluation included two scoring tools from the US; one each from Spain, Germany, and Poland; the Korean Colorectal Screening(KCS) scores; and the modified Asia Pacific Colorectal Screening(APCS) scores. The c-statistics, sensitivity, specificity, positive predictive values(PPVs), and negative predictive values(NPVs) of these systems were evaluated. The resources required were estimated based on the Number Needed to Screen(NNS) and the Number Needed to Refer for colonoscopy(NNR). Advanced neoplasia was detected in 364 (6.2%) subjects. The German system referred the least proportion of subjects (11.2%) for colonoscopy, whilst the KCS scoring system referred the highest (27.4%). The c-statistics of all systems ranged from 0.56–0.65, with sensitivities ranging from 0.04–0.44 and specificities from 0.74–0.99. The modified APCS scoring system had the highest c-statistics (0.65, 95% C.I. 0.58–0.72). The NNS (12–19) and NNR (5-10) were similar among the scoring systems. The existing scoring systems have variable capability to predict advanced neoplasia among asymptomatic Chinese subjects, and further external validation should be performed.

226 Prospective Colonoscopy Study Identifies a Four-Fold Increased Risk of Advanced Colorectal Neoplasms Among Individuals With a Family History of Advanced Adenomas

Colorectal cancer (CRC) is the second most common cancer in Hong Kong. We previously showed that siblings of patients with CRC have an increased risk of colorectal neoplasms (Ng et al.) but there is a lack of prospective data on the risk estimates of colorectal neoplasms in siblings to subjects with adenomas. We assessed the prevalence of advanced adenomas and cancers in siblings of individuals with advanced adenomas compared with siblings with no such lesions.

Prospective Study of Sessile Serrated Adenomas Detected with Colonoscopy

About 15% of sporadic colorectal cancers exhibit high-frequency microsatellite instability (MSI-H) and inactivation of hMLH1 (a mismatch repair gene). In previous retrospective studies, similar molecular changes have been seen in hyperplastic polyps and sessile serrated adenomas in the proximal colon, leading to the theory that these lesions are precursors of sporadic MSI-H cancers in the proximal colon. In a new prospective colonoscopy study, investigators sought to determine the prevalence of serrated polyps, including hyperplastic polyps and serrated adenomas, and to describe the prevalence of BRAF and K -ras mutations in such polyps. BRAF and K -ras are involved in the same signaling pathway, and mutations in these genes are …