Cell-Free DNA Cancer Screening May Delay Diagnosis
A new study published in JAMA found that population-based cancer screening using cell-free DNA—a type of liquid biopsy analyzing blood tests for DNA shed by cancer cells—may actually delay cancer diagnosis in some cases. Researchers examined data from 21 cancer alliance regions in England, with eight participating in cell-free DNA screening and 13 not using it, comparing diagnostic delays before and after screening implementation. They discovered approximately a 5% difference in diagnostic delay between regions with and without the screening.
The issue, according to the study, stems from false positives and resource constraints. When many people test positive on screening but do not have cancer, it can divert healthcare resources away from others who need screening, and when either the cancer is detected too early to find or the positive test is false, it disrupts normal diagnostic pathways. There are now 24 different companies offering liquid biopsies. A prior study from one company released in February showed that its screening did not increase early cancer detection or reduce detection of advanced cancers (stages III or IV), suggesting these tests are not yet ready for widespread clinical use despite frequent advertising.
Resistance Training and Mortality Reduction
A new study in The BMJ examined whether long-term resistance training reduces mortality using data from three large prospective cohorts: the Health Professionals Follow-up Study and two nurse health studies, involving 147,000 participants followed for up to 30 years. Compared with no resistance training, individuals doing between 1.5 to 2 hours per week of resistance training had a 13% lower risk of all-cause mortality, a 19% lower risk of cardiovascular mortality, and a 27% lower risk of neurologic disease mortality—regardless of whether they also did aerobic exercise.
The greatest benefit came from combining both activities: individuals engaging in both resistance and aerobic exercise achieved up to 45% lower mortality. Notably, doing more than 2 hours of resistance training per week did not yield additional benefit over the 1.5 to 2-hour range, offering an encouraging finding that a modest commitment to exercise can significantly improve health outcomes for both men and women.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.medpagetoday.com/podcasts/healthwatch/121624