Associations between Ileal Juice Bile Acids and Colorectal Advanced Adenoma.

BACKGROUND: There is an urgent need to identify biomarkers for advanced adenoma, an important precursor of colorectal cancer (CRC). We aimed to determine alterations in ileal juice bile acids associated with colorectal advanced adenoma. METHODS: We quantified a comprehensive panel of primary and secondary bile acids and their conjugates using an ultraperformance liquid chromatography triple-quadrupole mass spectrometric assay in ileal juice collected at colonoscopy from 46 study subjects (i.e., 14 biopsy-confirmed advanced adenomas and 32 controls free of adenoma or cancer). Using analysis of covariance (ANCOVA), we examined the differences in bile acid concentrations by disease status, adjusting for age, sex, body mass index, smoking status and type 2 diabetes. RESULTS: The concentrations of hyodeoxycholic acid (HCA) species in ileal juice of the advanced adenoma patients (geometric mean = 4501.9 nM) were significantly higher than those of controls (geometric mean = 1292.3 nM, p = 0.001). The relative abundance of ursodeoxycholic acid (UDCA) in total bile acids was significantly reduced in cases than controls (0.73% in cases vs. 1.33% in controls; p = 0.046). No significant difference between cases and controls was observed for concentrations of total or specific primary bile acids (i.e., cholic acid (CA), chenodeoxycholic acid (CDCA) and their glycine- and taurine-conjugates) and total and specific major secondary bile acids (i.e., deoxycholic acid and lithocholic acid). CONCLUSIONS: Colorectal advanced adenoma was associated with altered bile acids in ileal juice. The HCA species may promote the development of colorectal advanced adenoma, whereas gut microbiota responsible for the conversion of CDCA to UDCA may protect against it. Our findings have important implications for the use of bile acids as biomarkers in early detection of colorectal cancer.

Association between Sleep Duration and Colorectal Adenomas: Findings from a Case-Control Study in Vietnam.

BACKGROUND: Colorectal cancer is one of the leading cancers worldwide and in Vietnam. Adenomas are important precursors of colorectal cancer. Study on the association between sleep duration and development of colorectal adenoma (CRA) is limited, particularly among Vietnamese population. METHODS: We conducted an individually matched case-control study of 870 CRA cases and 870 controls in a large-scale colorectal screening program involving 103,542 individuals ages ≥40 years old in Hanoi, Vietnam. Sleep duration was categorized in three groups: short: ≤6 hours/day, normal: 7 to 8 hours/day, and long: >8 hours/day. Conditional logistic regression was used to evaluate the association between sleep duration and adenomas risk after controlling for potential confounders. RESULTS: Overall, short-sleep duration was associated with increased risk of having CRA compared with normal duration [OR, 1.48; 95% confidence interval (CI), 1.12-1.97]. This pattern was present in both females (OR, 1.58; 95% CI, 1.14-2.18) and males (OR, 1.45; 95% CI, 1.08-1.93), with advanced adenomas (OR, 1.61; 95% CI, 1.09-2.38) and non-advanced adenomas (OR, 1.66; 95% CI, 1.19-2.32). Furthermore, the association between CRA development and short-sleep duration was more apparent among females who were nondrinker, nonobese, physically active, with proximal or both sided adenomas and with cardiometabolic disorder. Among males, the short-sleep duration was associated with CRA risk among never-smoking, cardiometabolic disorders, and obese. CONCLUSIONS: Short-sleep duration was associated with increased prevalence of both advanced and non-advanced CRAs among Vietnamese population. IMPACT: Findings from this study showed that maintaining an adequate sleep duration may have an important implication for colorectal adenoma prevention and control.

Findings from the first colorectal cancer screening among 103 542 individuals in Vietnam with systematic review of colorectal cancer screening programs in Asia-Pacific region.

BACKGROUND: Colorectal cancer is a leading cancer incidence and cause of death worldwide and in Vietnam. Although screening is considered an effective measure to prevent and control colorectal cancer, there is no such effort in Vietnam. METHODS: Between 01 January 2018 and 31 October 2019, a population-based colorectal cancer screening program was conducted in Hanoi, Vietnam. A health advocacy campaign and follow-up phone calls were used to enroll residents aged ≥40 years old to complete an immunochemical-fecal occult blood testing. Positive immunochemical-fecal occult blood testing was followed by a colonoscopy. We also conducted a systematic review of the colorectal cancer screening programs in the Asia-Pacific region that used similar approach by searching Ovid Medline and PubMed databases. RESULTS: During study period, 103 542 individuals among 672 742 eligible residents attended the screening of whom 81.5% participants finished immunochemical-fecal occult blood testing test and the positive rate was 6.1%. The coverage rate for immunochemical-fecal occult blood testing test was 11.9%. Among 2278 individuals who underwent colonoscopy, 3.5% were histologically diagnosed with cancer, 17.8% with advanced adenomas, and 23.1% with non-advanced adenomas. Males had significantly higher detection rate of advanced adenomas, cancer or ≥ two polyps/tumor than females (P < 0.0001). The systematic review showed that in two-step modality (i.e. immunochemical-fecal occult blood testing/fecal immunochemical test and colonoscopy), the test positive was from 4.1 to 10.6%. Once colonoscopy was performed subsequently, the rate of cancer among positive participants was from 1.7 to 16.4% and that of advanced adenomas was from 7.1 to 23.1%. CONCLUSION: We showed that the two-step modality is a promising strategy for colorectal cancer screening in Vietnam that might apply to similar settings with limited resources.

Association between body mass index and colorectal adenomas: Findings from a case-control study in Vietnam.

Colorectal cancer is a leading cancer worldwide and in Vietnam. Adenomas (adenomatous polyps) is an important precursor of colorectal cancer. There is currently no study to determine the modifiable risk factors for colorectal adenomas, including body mass index (BMI) in Vietnam. We conducted an individually matched case-control study of 1149 colorectal adenomas and 1145 controls in a large-scale colorectal screening program involving 103 542 individuals aged 40-75 years old in Hanoi, Vietnam. Conditional logistic regression was used to evaluate the association between BMI and colorectal adenomas prevalence, after controlling for potential confounders. Overall, comparing to normal weight (ie, 18.5-22.9 kg/m2 ), underweight (ie, BMI < 18.5) was associated with a non-statistically significant increased prevalence of colorectal adenomas (odd ratio [OR] = 1.29 and 95% confident interval [CI]: 0.88-1.87). This association became significant among male (OR = 1.98, 95% CI: 1.20-3.27), male who were ever smokers (OR = 2.59, 95% CI: 1.33-5.03), nonregular exercise (OR = 2.44, 95% CI: 1.26-4.73) and individuals with cardiometabolic disorders (OR = 3.46, 95% CI: 1.19-10.00). The association between underweight and colorectal adenomas did not vary by smoking status, drinking status, family history of cancer, adenomas types or cardiometabolic disorders. No association was observed among obese individuals (BMI ≥ 25). In the population with low prevalence of obesity, we found that the association between BMI and colorectal adenomas followed a reversed J-shape that underweight was associated with increased prevalence. Further studies are, therefore, warranted to replicate our results and to investigate the biologic mechanism the effect of underweight on colorectal adenomas prevalence.

Attributable Causes of Cancer in Vietnam.

PURPOSE: Vietnam is undergoing rapid socio-economic transition with an increasing cancer burden. The contribution of modifiable risk factors to cancers in Vietnam has not been studied. Therefore, we sought to evaluate the attributable causes of cancer in Vietnam. METHODS: We reviewed the data on burden of cancer in Vietnam from 2 cancer registries in Hanoi and Ho Chi Minh City between 1995 and 2012. Next, we calculated the fractions of cancers occurring in 2018 attributable to established modifiable risk factors whose impact could be quantified. Data on exposure prevalence were obtained for the period from 2000 to 2010 from national sources wherever possible. RESULTS: Cancer incidence in Vietnam has decreased slightly in both sexes. Cancer related to infectious agents decreased sharply, whereas cancer related to nutrition and metabolism has increased. In 2018, established carcinogens included in the analysis explained 47.0% of cancer burden in Vietnam. Chronic infections accounted for 29.1% of cancers (34.7% in men and 22.1% in women), tobacco smoking for 13.5% (23.9% in men and 0.8% in women), and alcohol drinking for 10.3%. Passive smoking was responsible for 8.8% of cancers in women. Other risk factors, including overweight or obesity, nulliparity, and low vegetable and fruit intake, accounted for < 1% of all cancers each. CONCLUSION: Cancer incidence is slowly decreasing in Vietnam, and the causes of more than half of cancers remain unexplained. This result underlines the need for further epidemiologic and fundamental research. Our findings confirm the notion that controlling oncogenic infections and decreasing tobacco smoking are the most effective approaches to reduce the burden of cancer in Vietnam, but other risk factors, including alcohol drinking and diet, should not be neglected.