According to data presented at the 13th European Breast Cancer Conference, women who receive a benign breast disease diagnosis through screening have an almost doubled risk of developing breast cancer.

The study compared women who were diagnosed with any benign breast disease, including fibroadenomas and cysts, with those who had not received a breast disease diagnosis. It involved more than 7,00,000 Spanish women who participated in breast screening.

Researchers think this group of women could benefit from more regular screening to ensure those who get cancer are caught early when survival chances are at their highest. The elevated risk of breast cancer continued for at least two decades.

Dr Marta Roman from the Hospital del Mar in Barcelona, Spain, presented the study at the conference and it was also published in the International Journal of Environmental Research and Public Health.

It comprised 778,306 women between the ages of 50 and 69 who underwent breast screening at least once at one of 20 centres in Spain between 1996 and 2015. In Spain, mammography for breast cancer screening is provided to all women in this age group every two years.

Researchers monitored the women up until 2017, at which time 17,827 of them had benign breast illness diagnoses while 11,708 received breast cancer diagnoses.

According to the data, about 25 out of every 1,000 women with benign breast illness went on to receive a breast cancer diagnosis. About 15 out of every 1,000 women without benign breast illness received a breast cancer diagnosis. Regardless of age, women with benign breast disease were found to be at increased risk, and the risk persisted for at least 20 years.

Breast cancer diagnoses were 99 per cent more likely to occur in women who were followed up for less than four years than they were in those who were followed up for 12 to 20 years.

"This is important," Dr Roman explained. "It suggests that benign breast disease is a key indicator that a woman has a higher risk of breast cancer, rather than simply being something that could develop into cancer. In fact, we often find a benign disease in one breast and then cancer develops in the other breast."

"We can use this knowledge, alongside what we know about other risk factors, to help optimise the breast screening that we offer to women. For example, if a woman is diagnosed with a benign breast disease, and she has other high-risk factors, such as a family history of breast cancer, she could benefit from more frequent screening."

President of the European Breast Cancer Council, professor David Cameron, from the University of Edinburgh Cancer Research Centre, UK, represents the Council at EBCC13 and was not involved with the research.

He said: "Screening can help diagnose breast cancer at an earlier stage when the chances of survival are greater. This large study shows that women in a screening programme who are diagnosed with a benign breast disease appear to be at a higher risk of being diagnosed with breast cancer in the long term and they may therefore benefit from enhanced screening."

"Mammograms quite often pick up signs of breast disease that are not cancer, such as cysts and fibroadenomas, and it's important to remember that the majority of women with these conditions will not go on to develop breast cancer."