Longitudinal assessment of colonoscopy adverse events in the prospective Cooperative Studies Program no. 380 colorectal cancer screening and surveillance cohort

Risk-stratified screening and colorectal cancer incidence and mortality: A retrospective study from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

OBJECTIVE

To determine whether risk stratification can optimize the benefits of flexible sigmoidoscopy (FSG) screening.

METHODS

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial was conducted from 1993 to 2001 in the United States. A colorectal cancer (CRC) risk stratification tool was developed in the control arm (n = 64,207) from the PLCO cohort and validated in the UK Biobank (n = 270,726). PLCO participants (n = 130,021) were classified into low-, medium-, and high-risk groups. Cumulative incidence and mortality were estimated using the Kaplan-Meier method. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between screening and CRC incidence and mortality.

RESULTS

The CRC risk stratification tool was based on age, gender, body mass index, smoking status, family history of CRC, diabetes, regular use of aspirin, and CRC screening history. Compared with the control arm, FSG screening was significantly associated with a reduction in mortality in both the medium-risk (HR = 0.76, 95% CI = 0.63-0.92) and high-risk groups (0.58, 0.46-0.73), but not in the low-risk group (0.85, 0.61-1.19). FSG screening also reduced distal CRC incidence and mortality in the medium-risk and high-risk groups. Furthermore, it was associated with a reduction in incidence (0.74, 0.59-0.92) and mortality (0.59, 0.40-0.87) of proximal colon cancer in the high-risk group.

CONCLUSIONS

FSG screening yielded more benefits for the high-risk group than for the low-risk and medium-risk groups, supporting the development of a risk-stratified CRC screening strategy.

Colorectal Cancer Polygenic Risk Score Is Associated With Screening Colonoscopy Findings but Not Follow-Up Outcomes

Background and Aims

Colorectal cancer (CRC) polygenic risk scores (PRS) may help personalize CRC prevention strategies. We investigated whether an existing PRS was associated with advanced neoplasia (AN) in a population undergoing screening and follow-up colonoscopy.

Methods

We evaluated 10-year outcomes in the Cooperative Studies Program #380 screening colonoscopy cohort, which includes a biorepository of selected individuals with baseline AN (defined as CRC or adenoma ≥10 mm or villous histology, or high-grade dysplasia) and matched individuals without AN. A PRS was constructed from 136 prespecified CRC-risk single nucleotide polymorphisms. Multivariate logistic regression was used to evaluate the PRS for associations with AN prevalence at baseline screening colonoscopy or incident AN in participants with at least one follow-up colonoscopy.

Results

The PRS was associated with AN risk at baseline screening colonoscopy (P = .004). Participants in the lowest PRS quintile had more than a 70% decreased risk of AN at baseline (odds ratio 0.29, 95% confidence interval 0.14-0.58; P < .001) compared to participants with a PRS in the middle quintile. Using a PRS cut-off of more than the first quintile to indicate need for colonoscopy as primary screening, the sensitivity for detecting AN at baseline is 91.8%. We did not observe a relationship between the PRS and incident AN during follow-up (P = .28).

Conclusion

A PRS could identify individuals at low risk for prevalent AN. Ongoing work will determine whether this PRS can identify a subset of individuals at sufficiently low risk who could safely delay or be reassured about noninvasive screening. Otherwise, more research is needed to augment these genetic tools to predict incident AN during long-term follow-up.

Fecal Calprotectin in Gastrointestinal Disease

BACKGROUND

Inflammatory bowel disease (IBD) comprises a group of chronic conditions characterized by relapsing and remitting inflammation of the gastrointestinal tract. The incidence is increasing worldwide, and the therapeutic options for management are expanding. Endoscopy is the gold standard investigation for diagnosis of IBD and for assessing mucosal healing, which is increasingly being used as a measure of disease control. However, it is an invasive procedure that is unpleasant for patients and expensive and time-consuming for hospitals. Fecal calprotectin has been shown to be an accurate surrogate marker of gastrointestinal inflammation in IBD.

CONTENT

Fecal calprotectin was initially used for the diagnosis of IBD but is now recognized as having a role in assisting in assessment of disease activity, prediction of relapse, and informing decisions around therapy and may help to minimize requirement for endoscopy. However, there are various preanalytical and analytical factors that can affect interpretation of the results; these need to be understood to optimize clinical care.

SUMMARY

Preanalytical and analytical factors that can potentially influence fecal calprotectin concentrations are examined, and an overview is provided of clinical situations in which fecal calprotectin is commonly measured.

Application of a multispecies probiotic reduces gastro-intestinal discomfort and induces microbial changes after colonoscopy

Even after decades of research and pharmaceutical development, cancer is still one of the most common causes of death in the western population and the management of cancer will remain a major challenge of medical research. One of the most common types of cancer is colorectal cancer (CRC). Prevention by detection of early-stage precursors is the most reliable method to prevent CRC development. In dependence of age, familial predisposition, and other risk factors the preventative routine screening for CRC by colonoscopy should be performed at least twice in intervals of about ten years. Although colonoscopy is a life-saving clinical examination reducing both incidence and mortality of CRC significantly, it has still a bad reputation in the population as an uncomfortable procedure with unpleasant side effects lasting sometimes over days to weeks. These effects are most likely caused by the bowel preparation before colonoscopy, which is crucial for a successful colonoscopy with high quality. Beside pain, bleeding and other rare but severe complications of colonoscopy, cleaning of the intestinal mucosa alters the gut microbiome significantly and consistently. Abdominal pain, cramps, diarrhea, nausea, bloating, and constipation are common adverse events which can continue to affect patients for days or even weeks after the procedure. In this multicenter, placebo controlled, double blind clinical trial, we investigated the effect of an intervention with a multispecies probiotic formulation for 30 days on the adverse events due to bowel preparation. We show that the treatment of participants with the multispecies probiotic formulation decreases the number of days with constipation significantly, and reduced pain, bloating, diarrhea, and general discomfort. 16S based amplicon analyses reveal recovery of administered probiotic strains from stool samples and differences in alpha diversity dynamics with higher variability in the probiotic group compared to the placebo group. In conclusion, the probiotic ameliorates the side effects after colonoscopy and might be an important supplement to increase acceptance of this life-saving preventative examination. Further, we present here for the first time that probiotic intervention of only 30 days affects alpha diversity parameters in stool samples.