Socioeconomic inequalities in interval colorectal cancer are explained by differences in faecal haemoglobin concentration and age: a register-based cohort study

Interval cancer risk after the upper age limit of screening has been reached: Informing risk stratification in FIT-based colorectal cancer screening

Upper age limits are currently fixed for all fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening programs. A risk-stratified upper age limit may be beneficial. Therefore, we assessed differences in interval CRC risk among individuals who had reached the upper age limit of screening (75 years). Individuals with a negative FIT (<47 μg Hb/g feces) in the final round of the Dutch CRC screening program were selected from the national screening database and linked to the national cancer registry to identify CRCs diagnosed within 24 months (interval CRCs). Survival analyses assessed whether sex and last fecal hemoglobin (f-Hb) concentration were associated with interval CRC risk. A multivariable logistic regression assessed whether sex, last f-Hb concentration and screening round were associated with stage distribution (early vs. late). Last f-Hb concentrations were considered detectable when they were >0 μg Hb/g feces. Among 305,761 individuals with a complete follow-up (24 months), 661 were diagnosed with interval CRC (21.6 per 10,000 negative FITs). Individuals with detectable f-Hb (15%) were 5 times more likely to be diagnosed with interval CRC than those without (HR 4.87, 95%CI: 4.19-5.65). Moreover, their cancers were more often detected at a late stage compared to individuals without detectable f-Hb (OR 1.45, 95%CI: 1.06-2.01). Our results show that interval CRC risk among individuals aged ≥75 differs substantially by last f-Hb concentration, indicating a uniform age to stop screening is suboptimal. Future research, taking into account multiple screening rounds and FIT results, should determine the optimal risk-stratified screening strategy.

Fecal Hemoglobin Levels in Prior Negative Screening and Detection of Colorectal Neoplasia: A Dose-Response Meta-Analysis

BACKGROUND & AIMS

Prior studies have shown that individuals with fecal hemoglobin (f-Hb) concentrations just below the positivity cutoff have an increased colorectal cancer risk compared with those with no or low f-Hb. Understanding the dose-response association between f-Hb in a prior screening round and the detection of colorectal neoplasia is crucial for tailoring risk-based screening recommendations.

METHODS

We searched the literature to identify studies reporting the association between f-Hb in prior screening round and colorectal neoplasia detection in an average-risk population. Analysis involved a 2-stage approach using log-log regression models to assess dose-response relationships across studies, with effect sizes pooled using a random effects model. Heterogeneity was assessed by excluding individual studies in sensitivity analyses. Subgroup analyses examined variations in effects by outcome definitions and detection methods.

RESULTS

This systematic review and meta-analysis included 13 studies with 4,493,672 individuals. All studies demonstrated a positive association between f-Hb in prior screenings and colorectal neoplasia detection. Pooled analysis revealed that individuals with f-Hb concentrations of 5, 10, 20, and 40 μg/g had a 3-, 5-, 8-, and 13-fold higher risk of colorectal neoplasia, respectively, compared with individuals with 0 μg/g. Although significant heterogeneity (I2 = 97.5%, P < .001) was observed, sensitivity analyses confirmed the consistency of findings. Subgroup analyses indicated that f-Hb concentrations from previous negative tests were especially predictive of advanced neoplasia in subsequent screenings.

CONCLUSIONS

Our findings suggest that the risk of detecting colorectal neoplasia increases with prior f-Hb concentrations in negative tests, supporting the development of risk-stratified screening strategies based on these concentrations.

Factors associated with negative colonoscopy in participants with a positive faecal immunochemical test from the Danish Colorectal Cancer Screening Program - a population-based study

AIM

In the Danish Colorectal Cancer Screening Program (DCCSP), 37% of participants undergoing colonoscopy have a negative result with no obvious findings that can be attributed to a positive faecal immunochemical test (FIT). The aim of this work was to identify predictors for a negative colonoscopy in DCCSP participants with a positive FIT.

METHOD

We included 73 655 FIT-positive DCCSP participants using the Danish Colorectal Cancer Screening Database and linked their screening results with data from several other national health registers. We stratified participants by all predictors, and compared them using multivariate logistic regression analysis. Results are reported as odds ratios (ORs).

RESULTS

We found that having a condition linked to gastrointestinal bleeding, for example fissures, haemorrhoids and inflammatory bowel disease, was strongly associated with the probability of having a negative colonoscopy [OR 2.77 (95% CI 2.59, 2.96)]. FIT concentration was inversely related to the probability of a negative colonoscopy, the OR decreased steadily from 0.79 (95% CI 0.75, 0.83) in the 40-59 μg/g group, to 0.44 (95% CI 0.42, 0.46) in the ≥200 μg/g group. Women had a 1.64 (95% CI 1.59, 1.70) times higher probability of a negative colonoscopy than men.

CONCLUSION

Our findings indicate that baseline conditions linked to gastrointestinal bleeding are an associating factor with having a negative colonoscopy. The same is true for low FIT concentration and female sex. Further studies with similar findings could suggest that an incorporation of these factors into a personalized screening approach by differentiating between diagnostic modalities could improve the process for the participant while alleviating the health care system.