Elevated FIT Result Ups All-Cause and Non-CRC Mortality Risk

TOPLINE:

In an English cohort study, patients with symptomatic presentation of colorectal cancer (CRC) and faecal immunochemical test (FIT) results ≥ 10 µg of haemoglobin (Hb)/g had a higher risk for 1-year all-cause and non-CRC mortality than those with FIT results < 10 μg of Hb/g.

METHODOLOGY:

• Researchers conducted a retrospective study of a cohort of 49,889 adults with symptoms of CRC who underwent a FIT at Nottingham University Hospitals from November 2017 to November 2022.
• Of those included, 10,352 had a FIT result ≥ 10 μg of Hb/g (median age, 72 years; 52.5% women; 75.1% White) and 39,537 had a FIT result < 10 μg of Hb/g (median age, 63 years; 56.9% women; 67.8% White).
• Primary outcomes were all-cause and non-CRC mortality, with follow-up censoring at either death or 1 year after FIT.

TAKEAWAY:

• In the year following symptomatic FIT, mortality rates were significantly higher in patients with FIT results ≥ 10 μg of Hb/g than in those with FIT results < 10 μg of Hb/g (8.3% vs 2.8%); the rate of non-CRC deaths was 92.4%.
• The rate of all-cause mortality was higher among patients with higher FIT results than among those with lower FIT results (87.21 vs 28.41 per 1000 person-years). Similar outcomes were observed for non-CRC deaths (74.79 vs 27.72 per 1000 person-years).
• After adjusting for age, sex, and year, patients with FIT results ≥ 10 μg of Hb/g had a higher risk for all-cause mortality (adjusted hazard ratio [aHR], 1.96) and non-CRC mortality (aHR, 1.70; P < .0001 for both) than those with FIT results < 10 μg of Hb/g.
• Standardised mortality ratios for patients with FIT results ≥ 10 μg of Hb/g were higher for both all-cause mortality (2.12) and non-CRC deaths (1.86).

IN PRACTICE:

“We found in our regional study in England that patients undergoing FIT for investigation of symptoms were at increased risk of mortality at 1 year following the test, and mortality was highest among those with FIT results of 10 µg of haemoglobin per g or higher,” the authors wrote. “Both the risks of all-cause and non-colorectal cancer deaths were increased, and the relative risks were even greater among younger and female patients who were tested,” they added.

SOURCE:

This study was led by Francesca L. Malcolm, MSc, School of Medicine, University of Nottingham, Nottingham, England. It was published online on August 08, 2025, in The Lancet Primary Care.

LIMITATIONS:

A large proportion of ethnicity data were missing, potentially affecting the generalisability of the results. The researchers were unable to examine outcomes for individuals who did not return their FITs. Potential biases existed due to misclassification and residual confounding from unmeasured factors like comorbidity, colonoscopy results, and use of antiplatelets or anticoagulants.

DISCLOSURES:

This study did not receive any specific funding. Malcolm received funding through a National Institute for Health and Social Care Doctoral Fellowship when manuscript revisions were carried out. Three authors reported receiving grant funding from the UK National Institute for Health and Care Research. Additional disclosures are listed in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.