Occult Blood in Feces Is Associated with Increased Risk of Psoriasis

Systematic review: Mortality associated with raised faecal immunochemical test and positive faecal occult blood results

BACKGROUND

Faecal haemoglobin (f-Hb) testing is used in colorectal cancer (CRC) screening and increasingly to guide the investigation in patients with symptoms suggestive of CRC. Studies have demonstrated increased mortality with raised f-Hb.

AIMS

To assess the association of raised f-Hb with all-cause, non-CRC (any cause excluding CRC) and cause-specific mortality.

METHODS

We searched Medline and Embase on 9 February 2024 to identify papers reporting mortality after faecal immunochemical (FIT) or guaiac faecal occult blood tests (gFOBT). The primary outcome was all-cause mortality following a positive compared to a negative test.

RESULTS

The search identified 3155 papers. Ten met the inclusion criteria: three reported gFOBT and seven reported FIT results, as screening tests. These reported a total of 14,687,625 f-Hb results. Elevated f-Hb was associated with an increased risk of all-cause, non-CRC and cause-specific mortality including death from cardiovascular, digestive and respiratory diseases. Crude risk ratios for all-cause mortality with a positive versus negative test were derived from six papers (three reporting gFOBT, three FIT). An increased risk was demonstrated in five, with RRs ranging from 1.11 (95% CI: 1.06-1.16) to 2.95 (95% CI: 2.85-3.05). For non-CRC mortality risk, RRs ranged from 1.09 (95% CI: 1.04-1.15) to 2.79 (95% CI: 2.70-2.89). We did not perform meta-analysis due to a limited number of papers reporting suitable results for each type of f-Hb test.

CONCLUSIONS

All-cause, non-CRC and cause-specific mortality appear higher in those with raised f-Hb. Population-based studies are warranted to elicit whether this association occurs in symptomatic patients.

Positive Results from the Fecal Immunochemical Test Can Be Related to Dementia: A Nationwide Population-Based Study in South Korea

BACKGROUND

The fecal immunochemical test (FIT) is widely used in screening for colorectal cancer (CRC), but FIT results can be positive for diseases other than CRC.

OBJECTIVE

We investigated the association between positive results of FIT and the incidence of dementia using a nationwide database.

METHODS

FIT-positive participants were collected from a database provided by the Korean National Health Insurance Service.

RESULTS

The incidence of all kinds of dementia was higher in FIT-positive than FIT-negative subjects (p < 0.0001). FIT-positive participants had a higher risk of Alzheimer's disease (AD) (p < 0.0001) and vascular dementia (p = 0.0002), compared to participants with FIT negativity. The risk of all kinds of dementia or AD in FIT-positive participants was higher in younger (age < 65 years) than older participants (p < 0.0001 for all kinds of dementia; p = 0.0002 for AD).

CONCLUSION

FIT positivity was correlated with an increased risk of dementia, especially in participants under 65 years of age. The study suggests that clinicians can consider dementia when FIT-positive participants fail to show any malignancies.

Positive faecal immunochemical test predicts the onset of inflammatory bowel disease: A nationwide, propensity score-matched study

Background & aims

The faecal immunochemical test (FIT), a non-invasive test for screening colorectal cancer (CRC), is being increasingly understood to reflect heightened inflammation. We aimed to investigate the association between abnormal FIT results and onset of inflammatory bowel disease (IBD), a disease characterized with chronic gut mucosal inflammation.

Methods

Participants in the Korean National Cancer Screening Program for CRC between 2009-2013 were analysed and divided into positive and negative FIT result groups. The incidence rates of IBD after screening were calculated after excluding cases of haemorrhoids, CRC, and IBD at baseline. Cox proportional hazard analyses were used to identify independent risk factors for IBD occurrence during follow-up, and 1:2 propensity score matching was performed as a sensitivity analysis.

Results

In total, 229,594 and 815,361 participants were assigned to the positive and negative FIT result groups, respectively. The age- and sex-adjusted incidence rates of IBD in participants with positive and negative test results were 1.72 and 0.50 per 10,000 person-years, respectively. Adjusted Cox analysis revealed that FIT positivity was associated with a significantly higher risk of IBD (hazard ratio 2.93, 95% confidence interval: 2.46, 3.47, P <.001), which was consistent for both disease subtypes of ulcerative colitis and Crohn's disease. The results of Kaplan-Meier analysis in the matched population yielded identical findings.

Conclusions

Abnormal FIT results could be a preceding sign of incident IBD in the general population. Those with positive FIT results and suspected IBD symptoms could benefit from regular screening for early disease detection.

Faecal haemoglobin concentrations are associated with all-cause mortality and cause of death in colorectal cancer screening

BACKGROUND

Colorectal cancer (CRC) screening reduces all-cause and CRC-related mortality. New research demonstrates that the faecal haemoglobin concentration (f-Hb) may indicate the presence of other serious diseases not related to CRC. We investigated the association between f-Hb, measured by a faecal immunochemical test (FIT), and both all-cause mortality and cause of death in a population-wide cohort of screening participants.

METHODS

Between 2014 and 2018, 1,262,165 participants submitted a FIT for the Danish CRC screening programme. We followed these participants, using the Danish CRC Screening Database and several other national registers on health and population, until December 31, 2018. We stratified participants by f-Hb and compared them using a Cox proportional hazards regression on all-cause mortality and cause of death reported as adjusted hazard ratios (aHRs). We adjusted for several covariates, including comorbidity, socioeconomic factors, demography and prescription medication.

RESULTS

We observed 21,847 deaths in the study period. Our multivariate analyses indicated an association relationship between increasing f-Hb and the risk of dying in the study period. This risk increased steadily from aHR 1.38 (95% CI: 1.32, 1.44) in those with a f-Hb of 7.1-11.9 μg Hb/g faeces to 2.20 (95% CI: 2.10, 2.30) in those with a f-Hb ≥60.0 μg Hb/g faeces, when compared to those with a f-Hb ≤7.0 μg Hb/g faeces. The pattern remained when excluding CRC from the analysis. Similar patterns were observed between incrementally increasing f-Hb and the risk of dying from respiratory disease, cardiovascular disease and cancers other than CRC. Furthermore, we observed an increased risk of dying from CRC with increasing f-Hb.

CONCLUSIONS

Our findings support the hypothesis that f-Hb may indicate an elevated risk of having chronic conditions if causes for the bleeding have not been identified. The mechanisms still need to be established, but f-Hb may be a potential biomarker for several non-CRC diseases.

Faecal Haemoglobin Estimated by Faecal Immunochemical Tests-An Indicator of Systemic Inflammation with Real Clinical Potential

Multimorbidity is the major cause of ill-health and premature death in developed countries. The ability to identify individuals at risk of developing chronic disease, particularly multimorbidity, reliably, and simply, and to identify undiagnosed disorders, is vital to reducing the global burden of disease. This narrative review, the first of recent studies, demonstrates that raised faecal haemoglobin concentration (f-Hb) is associated with increased all-cause and cause-specific mortality and with longer-term conditions including diabetes, hypertension, cardiovascular disease, and psoriasis, and with probable intake of particulate matter. We and others have hypothesized that elevated f-Hb (measured using a faecal immunochemical test) has considerable potential to identify individuals at risk of, or who already have, early stage, undiagnosed chronic disease. If f-Hb does prove to be an effective biomarker for chronic disease and multimorbidity, individuals with detectable f-Hb, but without an obvious source of gastrointestinal blood loss, could benefit from further assessment and early intervention. To test this hypothesis rigorously, longitudinal data-linkage methodology is required linking colorectal cancer screening data, and data on patients presenting with lower gastrointestinal symptoms, with routinely collected health information.