A new blood test could help detect signs of more than 50 types of cancer through a single blood sample. Known as a multi-cancer early detection test, it searches for DNA fragments released by tumours into the bloodstream.
Potential for Earlier Detection
The test could be particularly useful for cancers that currently have no routine screening methods. As per CNN, many cancers are diagnosed only after symptoms appear, when treatment can be more difficult. Early detection could therefore give patients more opportunities for timely treatment.
However, the test has important limitations. A negative result does not rule out cancer, while a positive result requires further tests to confirm whether cancer is actually present. In a major study, the test detected about one-third of cancers diagnosed during the following year and missed many others.
Not a Replacement for Existing Screening
Therefore, experts stress that the blood test should complement, rather than replace, established screening methods such as mammograms and colonoscopies. CNN also reported concerns that people who receive a negative result could wrongly assume they do not need routine screening.
More Research Needed
The US Food and Drug Administration’s advisory panel supported the test’s potential benefits but raised concerns about its effectiveness and the possibility of false reassurance or false alarms. Further studies are still needed to determine whether using such tests can reduce cancer deaths and improve long-term outcomes.