Effect of Cotinine-Verified Change in Smoking Status on Risk of Metachronous Colorectal Neoplasia After Polypectomy

Design and verification of individualized follow-up strategy of colonoscopy for postoperative patients with colorectal cancer

BACKGROUND

Current guidelines do not establish an individual scheme for surveillance colonoscopy in postoperative colorectal cancer (CRC) patients.

AIMS

The purpose of the study was to screen possible risk factors for the development of metachronous adenoma in postoperative CRC patients and to develop a risk prediction model and verify it.

METHODS

Consecutive postoperative patients with CRC were enrolled from April 2007 to December 2013 as the derivation group. Baseline data of patients and clinicopathological features of the tumor were collected, logistic regression analysis was performed, and clinical model was established and was verified internally. The model was externally validated in an independent cohort (validation group) from January 2014 to October 2017 in the same hospital.

RESULTS

A total of 734 patients were included, with average (64.6 ± 11.5) years old. The overall incidence of metachronous adenoma was 35.4%. There was no significant difference in the incidence of metachronous adenoma between the derivation group and validation group (P > 0.05). Age, diabetes mellitus, right colon cancer, moderately to poorly differentiated adenocarcinoma and synchronous adenoma were independent risk factors for metachronous adenoma. The C-index of the metachronous adenoma line chart model was 0.932, and the index decreased by 0.022 after internal verification. The C-index of external validation was 0.910. The Hosmer-Lemeshow test showed that the P value of metachronous adenoma risk prediction model was 0.247.

CONCLUSIONS

Individual surveillance strategies should be designed for postoperative patients with CRC. For high-risk patients, it is appropriate to undergo more than two colonoscopies in 36 months after operation.

The risk of colorectal neoplasm in ex- and never-smokers according to urinary cotinine level

To investigate the relationship between urinary cotinine and colorectal neoplasm (CRN).The participants in the health screening cohort of the National Cancer Center who underwent screening colonoscopy between June 2007 and December 2009 were included. A total of 8121 subjects who underwent urinary cotinine measurement within 14 days from the index colonoscopy were included. Cotinine positivity was defined as having a urinary cotinine level ≥50 ng/mL. Follow-up colonoscopy data were collected by reviewing the patients' medical records.Patients were classified according to their urinary cotinine level and self-reported smoking status, and the number of patients with cotinine positivity was 1960 (24.1%). There was no significant difference in the cumulative CRN and advanced CRN (ACRN) risks according to the self-reported smoking status. However, cotinine positivity at the time of index colonoscopy was an independent risk factor for CRN (hazard ratio [HR]= 1.23, P = .006) in follow-up colonoscopy. Moreover, in never- and ex-smokers, cotinine positivity was an independent risk factor for CRN (HR = 1.95, P = .019; HR = 2.12, P = .003, respectively) and ACRN (HR = 8.89, P < .001; HR = 5.03, P = .003) during follow-up colonoscopy. The cumulative incidence of CRN and ACRN was higher in the cotinine-positive never- and ex-smokers than in the cotinine-negative never- and ex-smokers (P < .001 and P = .008, respectively).CRN or ACRN is more likely to occur at follow-up colonoscopy in the urinary cotinine-positive never- and ex-smokers than in the urinary cotinine-negative group. Therefore, urinary cotinine measurements may provide useful information on never- or ex-smokers undergoing screening colonoscopy.

Predictors of Metachronous Risk Polyps After Index Colonoscopy

INTRODUCTION

Guidelines for surveillance after polypectomy are lacking in strong evidence. Our aim was to identify some precursors of colorectal cancer lesions at 3 years after polypectomy to improve stratification and surveillance programs.

METHODS

We included patients with high-risk lesions (HRLs), defined as advanced adenoma (AA), large serrated polyps (SPs), and multiplicity (≥3 of any adenomas/SPs). Data on age, sex, cardiovascular risk factors, pharmacological treatment, and the histological characteristics in each individual, and mutations in genes involved in the most advanced index polyp, were collected. Parameters independently associated with a metachronous HRL diagnosis were evaluated through univariate and multivariate analyses. The results are reported as odds ratios and 95% confidence intervals along with P values.

RESULTS

A total of 537 cases (median age: 60.7 years; 66% male) were included. Dyslipidemia and smoking correlated with metachronous HRLs. Multivariate logistic regression analysis showed that the presence of multiplicity with ≥3 polyps on the index colonoscopy was significantly associated with metachronous HRL, AA, proximal AA, and ≥3 polyps at 3 years. In addition, independent predictors of metachronous proximal AA were increasing age, female sex, and the loss of expression of the MLH1 protein.

DISCUSSION

Multiplicity was a strong predictor of HRLs at 3 years, although the inclusion of other clinical variables (age, sex, smoking status, and dyslipidemia) improves surveillance recommendations. Without these risk factors, the surveillance could be extended to 5 years; we propose examining the somatic expression of MHL1 in all patients.

Risk of venous thromboembolism in Asian patients with inflammatory bowel disease: a nationwide cohort study

Routine prophylaxis for venous thromboembolism (VTE) in Asian IBD patients has been controversial. We aimed to estimate the risk of VTE of Asian patients at different phases of IBD by incorporating patient-specific risk factors. In this cohort study, we analyzed the National Health Insurance claims data between 2012 and 2016 for the entire Korean population. We calculated incidence rates and hazard ratios for VTE. The overall VTE risk was higher in patients with IBD [adjusted hazard ratio (aHR), 2.06; 95% confidence interval (CI), 1.66–2.55], than in controls. When we compare the risk of VTE by different disease phases, the risk of VTE was the highest during post-operation period after IBD-related bowel surgery (aHR, 39.7; 95% CI 9.87–159.3), followed by during hospitalized periods with flare (aHR, 27.2; 95% CI 14.9–49.65) and during hospitalized periods with non-flare (aHR, 16.23; 95% CI 10.71–24.58). The incidence rate (per 1000 person-years) was 15.26 during hospitalized periods with a flare and 9.83 during hospitalized periods with non-flare. According to age groups, the incidence rate (per 1000 person-years) during hospitalized periods with flare was 14.53 in young patients (20–39 years) and 34.58 in older patients (60–80 years). During hospitalized periods with non-flare, the incidence rate was 3.55 in young patients and 23.61 in older patients. The prophylaxis of VTE for Asian patients with IBD should be recommended in older patients admitted to hospital and be considered in young patients who are hospitalized with a flare.

Helicobacter pylori Infection and the Development of Advanced Colorectal Neoplasia

BACKGROUND

An association between Helicobacter pylori infection and colorectal neoplasia has been reported in cross-sectional studies.

GOALS

We examined the association between H. pylori infection and the development of advanced colorectal neoplasia (AN) in a screening cohort.

STUDY

We identified 3753 adults, who underwent screening and subsequent surveillance colonoscopies. The primary outcome was the development of metachronous AN, as confirmed by surveillance colonoscopy. H. pylori infection status was assessed by an H. pylori-specific immunoglobulin G antibody test. Sensitivity analysis was also performed by H. pylori infection status on the basis of histology.

RESULTS

During a median follow-up of 41 months, the incidence of AN was 3.2% and 1.7% in participants with and without H. pylori infection, respectively. In multivariable analysis adjusted for age, body mass index, smoking status, alcohol intake, family history of colorectal cancer, and baseline adenoma characteristics, the hazard ratio [95% confidence interval (CI)] for metachronous AN was 1.74 (1.11-2.73) in participants with H. pylori seropositivity, compared with those without H. pylori seropositivity. The association was consistent with H. pylori infection status on the basis of histology (adjusted hazard ratio, 3.51; 95% CI, 1.64-7.51). In the subgroup analysis, the positive association was observed in both no-adenoma and adenoma removal subgroups.

CONCLUSIONS

In a cohort study, H. pylori infection was associated with an increased risk of AN development. This association was consistent in both the serological and histologic assessment of H. pylori infection. Prospective studies are necessary to determine whether H. pylori eradication can reduce the risk of colorectal neoplasia.

Changes in Abdominal Obesity Affect the Risk of Metachronous Advanced Colorectal Neoplasia Development after Polypectomy

PURPOSE

The impact of changes in body mass index and waist circumference on the development of metachronous colorectal neoplasia (CRN) after polypectomy has rarely been examined. We evaluated the association between changes in overall/abdominal obesity and metachronous CRN risk.

MATERIALS AND METHODS

We studied patients who underwent ≥1 adenoma removal and surveillance colonoscopy. Patients were classified into the following four groups based on the changes in overall obesity from index to follow-up colonoscopy: non-obesity persisted (group 1), obesity to non-obesity (group 2), non-obesity to obesity (group 3), and obesity persisted (group 4). Patients were also divided into another four groups based on similar changes in abdominal obesity (groups 5-8).

RESULTS

The number of patients in groups 1, 2, 3, and 4 was 5074, 457, 643, and 3538, respectively, and that in groups 5, 6, 7, and 8 was 4229, 538, 656, and 2189, respectively. Group 4 had a significantly higher risk of metachronous CRN compared to groups 1 and 2. However, metachronous advanced CRN (ACRN) risk was not different among groups 1, 2, 3, and 4. Metachronous CRN risk in group 8 (abdominal obesity persisted) was higher than that in groups 5 (non-abdominal obesity persisted) and 7 (non-abdominal obesity to abdominal obesity), and tended to be higher than that in group 6 (abdominal obesity to non-abdominal obesity). Additionally, group 8 had a significantly higher risk of metachronous ACRN compared to groups 5, 6, and 7.

CONCLUSION

Changes in obesity affected the metachronous CRN risk. In particular, changes in abdominal obesity affected the metachronous ACRN risk.