ONE of the most common blood types has been identified as a potential breast cancer risk factor by scientists.
is the most common cancer among women worldwide, so identifying risk factors is vital for early and prevention.
While many studies have explored lifestyle and genetic causes, a new study focused on the .
By pooling global data, the researchers found blood type A was the most common among breast cancer patients, and was linked to an 18 per cent increased risk compared to type O.
In the UK, the most common blood type isO positive (O+), followed by A positive (A+).
O positive is found in about 36 per cent of the population, while A positive is found in around 30 per cent.
AB negative (AB-) is the rarest blood type, making up only one per cent of the population.
The study didn’t find a significant association between breast cancer and blood types B, AB, or Rh factor.
Blood groups are determined by the presence or absence of specific antigens on the surface of red blood cells.
The ABO system, which includes the A, B, and O antigens, and the Rh factor (RhD antigen) are the most important determinants of blood type.
Rh-positive individuals have the RhD antigen, while Rh-negative individuals lack it.
The researchers suggested blood group antigens in breast tissue may influence how cancer develops and spreads by interacting with the immune system or affecting cell behaviour.
This study is the most extensive review to date on this topic, based on studies conducted across , , and the Americas.
The researchers also noted regional differences, genetic diversity, and study quality may affect individual results.
But the overall trend supports considering blood type A as a potential risk marker.
This insight could help shape guidelines, encouraging earlier or more frequent checkups for women with this blood type.
Further researcher is needed to understand why blood type A may play a role in development.
How to find out your blood type
To determine your blood type, a sample of your blood needs to be taken and tested, usually by a blood donation service or a doctor.
You can find out your blood type by donating blood through organisations likeNHS Blood Donation.
You can also attendNHS Blood Donation’s What’s Your Blood Type eventto register as a donor and get a free blood type test.
