The larger the breasts, the higher the risk of cancer

Large breasts may cause an increased risk of breast cancer, according to a study by the American biotechnology company 23andMe, based on a survey of 16 thousand women. Scientists have discovered genetic mutations associated with the disease that are also associated with the regulation of the female sex hormone estrogen, which can cause the growth of both breast glands and tumors.

Scientists previously knew the link between breast density and cancer risk, but there was little evidence of a relationship with breast size. Study participants were asked to indicate their bra size, and scientists read the women's genetic code, looking for millions of tiny mutations in their DNA associated with breast size and breast cancer.

One of the three mutations regulates the activity of the estrogen receptor gene, which plays an important role in the formation of the mammary gland and may be involved in the formation of breast cancer. Another mutation is concentrated in the female genome, which often has abnormalities associated with some types of breast cancer.

It also found that women with a body mass index of 25 or less and a bra size D or larger had a significantly higher risk of breast cancer than women with the same body weight and a bra size A or smaller.

Although breast size is not the only risk factor, it can be one of many. Excess weight, alcohol abuse and strong heredity can also increase the risk of breast cancer. However, these results do not mean that women with small breasts can feel safe, so it is strongly recommended that all women get checked by a breast specialist.

The 23andMe study supports earlier research from the Harvard School of Public Health, which found that slender young women with larger breasts are more likely to develop breast cancer later in life.

Understanding biology can help develop new mass screening technologies, so further research in this area may be useful for preventing breast cancer and maintaining women's health.