Scientists have pinpointed a group of genetic markers that influence breast size.
According to a report in Live Science, some of these markers have previously been associated with breast cancer risk.
Study researcher Nicholas Erikkson and his team analysed responses from 16 175 women of European ancestry who answered questions about their bra cup size and band size, among others, and compared those answers to their genetics.
"There are surprising connections between some of the genes involved in determining breast size and the genes involved in breast cancer," Eriksson told the Huffington Post. However, the researchers emphasised that although a woman’s cup size and her risk of developing breast cancer could possibly be linked, the connection was "uncertain" and as yet "not a strong risk factor".
But while the study did not definitively link breast size to the risk of breast cancer, the findings could help clarify the role of breast structure in the risk of breast cancer, said a report in Live Science. Breast density has been established as a risk factor for breast cancer, for example, but the role of breast structure hasn’t been as well established.
More clear is the link between genes and breast size.
"Breast size is definitely heritable," Eriksson said. "But unlike height, where you can look at both parents and get some idea how tall you will be, you have much less data for breast size. A young woman can look at her mom. However, she won’t get the same insights by looking at her dad for his genetic contribution."
The study, published online in the journal BMC Medical Genetics, was conducted by genetic testing company 23andMe.