Faecal haemoglobin concentration predicts all-cause mortality

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.

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.

Insights Into Colorectal Cancer Screening: A Multidatabase Cohort Study of Over 1.5 Million Taiwanese

INTRODUCTION

Colorectal cancer (CRC) remains a significant public health concern. This study aims to provide a comprehensive understanding of the effectiveness of fecal immunochemical test (FIT) screening on CRC incidence and mortality, leveraging the scale of over 1.5 million randomly selected Taiwanese and more than 11.7 million person-years of follow-up.

METHODS

This prospective cohort study merges data from 3 robust Taiwanese health databases: the CRC screening program, cancer registration, and death registration databases. Incidence and mortality rates of CRC were calculated based on age, sex, urbanization, and past screening status. Cox proportional hazard models were used to assess the association between screening statuses and CRC incidence or mortality, adjusting for age, sex, and urbanization levels. Statistical analysis of the data was conducted in 2021-2022.

RESULTS

FIT screening was associated with a 33% reduction in CRC incidence and a 47% reduction in mortality. The study identified a dose-response relationship between the fecal hemoglobin concentration (f-HbC) levels and CRC risk. Participants with consistent FIT-negative results had significantly reduced CRC incidence and mortality risks, while those with one or more positive FIT results faced increased risks. Notably, compliance with follow-up examinations after a positive FIT significantly lowered mortality risk.

CONCLUSIONS

This large-scale study validates the efficacy of FIT screening in reducing CRC incidence and mortality. It offers a nuanced understanding of how various screening statuses impact CRC risks, thus providing valuable insights for public health strategies aimed at CRC prevention.

Socioeconomic differences in discrepancies between expected and experienced discomfort from colonoscopy and colon capsule endoscopy

Background

Social inequalities in colorectal cancer screening participation are evident. Barriers to screening participation include discomfort from diagnostic modalities. We aimed to describe the discomfort experienced from colonoscopy and colon capsule endoscopy (CCE) and investigate the discrepancy between expected and experienced discomfort stratified by socioeconomic status.

Methods

A randomised controlled trial was conducted offering half of the colorectal cancer screening invitees the choice between CCE and colonoscopy after a positive faecal immunochemical test. This paper includes those who elected to undergo CCE. A positive CCE elicited referral for a therapeutic colonoscopy. Participants reported their discomfort from CCE and from any following colonoscopies in electronically distributed questionnaires. Discomfort was measured using visual analogue scales and compared between socioeconomic subgroups determined by educational level and income.

Results

The experienced discomfort from CCE and colonoscopy differed significantly between educational levels but not income levels. The bowel preparation contributed the most to the experienced discomfort in both CCE and colonoscopy. The discrepancy between expected and experienced discomfort from colonoscopy increased with increasing educational and income levels. A similar trend was seen in CCE between educational levels but not income levels.

Conclusions

None of the results indicated a higher discomfort in lower socioeconomic subgroups. Regardless of the investigation modality, the bowel preparation was the main contributor to experienced discomfort. The discrepancy between expected and experienced discomfort did not seem to be larger in lower socioeconomic subgroups, indicating that this is not a major barrier causing inequalities in screening uptake. This is the first study investigating individual discomfort discrepancy in both CCE and colonoscopy, while being able to stratify by socioeconomic status.

Carrot Juice Intake Affects the Cytokine and Chemokine Response in Human Blood after Ex Vivo Lipopolysaccharide-Induced Inflammation

In vitro and animal studies have shown that carrot juice containing bioactive natural products, such as falcarinol (FaOH) and falcarindiol (FaDOH), can affect inflammation. The present study was designed to test whether oral intake of carrot juice containing the bioactive acetylenic oxylipins FaOH and FaDOH affects mediators of acute inflammation or the innate immune response in human blood. Carrot juice (500 mL) was administered orally to healthy volunteers, and blood samples were drawn before and 1 h after juice intake. Next, the blood samples were split in two, and one sample was stimulated ex vivo with lipopolysaccharide (LPS) and incubated at 37 °C for 24 h. The concentrations of 44 inflammatory cytokines and chemokines were examined using multiplex electrochemiluminescence analysis. In blood samples not stimulated with LPS, a significant increase in IL-15 was measured 1 h after carrot juice intake. Cytokines like IFN-ɣ, IL-12/IL-23(p40), IL-23, IL-17A, IL-17B, IL-17D, and IL-22 were significantly increased in LPS-stimulated blood samples after carrot juice intake. The upregulation of the immunostimulating cytokines belonging to the IL-23/IL-17 Th17 axis suggests that carrot juice intake could benefit diseases where inflammation plays a role, like in the early stages of diabetes or cancers.

Faecal haemoglobin: Measurement, applications, and future potential

Faecal hemoglobin concentrations (f-Hb) can be quantitated using faecal immunochemical test for haemoglobin (FIT) analytical systems. FIT are of proven value and widely used in colorectal cancer (CRC) screening. Several factors affect f-Hb including sex, age, deprivation, geographical region, and FIT system. Thus, FIT data may not be transferable. Women are disadvantaged in programmes using a single f-Hb threshold for all participants, but risk scoring or sex stratified thresholds could be used to minimise this problem. In addition, low but detectable f-Hb, below the threshold, implies future risk of CRC. In several countries, where colonoscopy resources are constrained, FIT are now accepted as of added value in assessment of patients presenting in primary or secondary care with symptoms, although some serious colorectal disease is missed. Elevated f-Hb in the absence of any discernible colorectal lesions is common and has been found in several diseases with a systemic inflammatory component, including circulatory, respiratory, digestive, neuropsychological, blood and endocrine diseases, and others. There is growing evidence for the value of f-Hb in post-polypectomy surveillance, potentially saving costs and colonoscopy. There may be a role for FIT systems which have lower limits of detection than currently available methods. The faecal material remaining in FIT specimen collection devices could be used for further studies, including assessment of the microbiome. The estimation of f-Hb is now a mature investigative tool but further research will undoubtedly expand applications of value.