A positive fecal occult blood test (FOBT) is now connected to a higher risk of death due to respiratory, neuropsychological and other causes, plus bowel and other cancers, says study.
- Stool test that tests positive for ‘invisible’ or occult blood indicates a high risk of dying from bowel cancer, plus more importantly, all other causes, including, respiratory, blood, circulatory, hormone and neuropsychological digestive diseases
- The positive test was strongly associated with all the conditions even after accounting for risk factors like age and gender
- The participants of a bowel cancer screening test might benefit if they are warned about the risk of other illnesses
Previous research has indicated that blood in the stool might predict life expectancy irrespective of whether a person has bowel cancer or not. But the research did not account for other potentially influential factors, including drugs like aspirin that might induce internal bleeding.
Study Design and Results
The researchers examined data of nearly 134,000 people, aged between 50 and 74 obtained from linked prescribing, bowel cancer screening, and death registry in Tayside, Scotland, from March 2000 to the end of March 2016. They tracked their survival from the date of the first test until death or the end of March 2016, whichever came first.- 2714 (just over 2%) tested positive for occult stool blood while 131,207 people tested negative during this period.
- Older people and those with increasing levels of deprivation, and belonging to the male gender were associated with a higher likelihood of a positive test result.
- Aspirin or other drugs that boost the risk of digestive tract bleeds were also influencing a positive test result.
- People who showed a positive FOBT result were nearly eight times as likely to die of bowel cancer compared to those who tested negative, after normalizing for gender, age, deprivation, and drug treatment.
- The most surprising result was that a positive FOBT result was also associated with a 58 percent heightened risk of death from all other causes like cardiovascular, respiratory, digestive tract, neuropsychological (how the brain correlates with the mind), blood disorders, and hormone imbalances, as well as other types of cancer, after normalizing for potentially influential factors.
"Although increased [unseen stool blood] cannot be a cause of death, it may reflect the reason why male gender, age and deprivation are such strong risk factors," they suggest.
The authors speculate that generalized inflammation that takes the form of gut inflammation and bleeding may be a suspect, as most solid cancers and Alzheimer's disease have been proved to develop against a background of chronic/systemic inflammation.
A positive FOBT result could be used in future to alert participants of a bowel cancer screening programme without the disease (which amounts to around half of those who test positive in the screening) that the test puts them at risk of other potentially life-limiting illness, and that they need a healthier lifestyle and/or preventive drug treatment.
Reference:
- Fecal Occult Blood Test (FOBT) - (https://medlineplus.gov/labtests/fecaloccultbloodtestfobt.html)