The study authors, based at Indiana and Harvard Universities in the US and INSERM, France, admit that whilst the findings are not definite, they believe that the number of moles could be used as a marker of breast cancer risk because moles are related to increased levels of sex hormones, a known risk factor for breast cancer.

Dr Matthew Lam, Senior Research Officer at Breakthrough Breast Cancer, said:

“This study doesn’t prove that moles can cause breast cancer, which the research team acknowledge, but there does seem to be an association between number of moles and the risk of developing the disease – potentially caused by the presence of higher levels of sex hormones, a known risk factor for breast cancer.

“Whilst the link is interesting, it’s not yet clear how useful asking women to report how many moles they have as part of risk estimation would be given that there are several other, more reliable, risk factors at play such as weight, age and genes. 

“Breakthrough scientists are discovering more and more each day about how various factors affect breast cancer risk, but based on past research we already know some proven steps women can take to reduce their chances of developing breast cancer. These include maintaining a healthy weight, limiting the amount of alcohol you drink and being regularly physically active – in fact, just 30 minutes of physical activity each day can reduce your risk of developing breast cancer by at least 20%.”