Contraception: risks and benefits

All types of hormonal contraceptives linked to breast cancer risk

Natalia Pelezneva, Naked Science

A slight increase in the risk of developing breast cancer persists for five years after the end of taking hormonal contraceptives of all types, including new ones.

Researchers from the UK and Denmark analyzed the health information of about 1.8 million women and came to the conclusion that even new types of hormonal contraceptives increase the likelihood of developing breast cancer. However, for women who do not have additional risk factors for the development of the disease, this probability is low.

The material for the analysis was the data of a cohort study that included all Danish women aged 15 to 49 years, with the exception of those who suffered from cancer or venous thromboembolism, as well as those who were treated for infertility. The follow-up period was 10.9 years, during which time 11,517 women developed breast cancer.

The risk of developing the disease increased with age – most of the cases occurred in women over 40 years of age. Also, the danger was not much, but increased for those who used one or another method of hormonal contraception, including intrauterine spirals and pills containing one or more hormones. Of the 100,000 women who used these methods, breast cancer developed on average 68 per year. Among women who have never resorted to hormonal contraception, this figure is 55 per year. The risk increased significantly for those who had used such contraceptives for more than 10 years. At the same time, women who took them for less than a year did not increase the likelihood of developing the disease. Five years after the end of taking contraceptives, the risk of breast cancer decreased again.

According to the researchers, the results of their work show how important it is to develop new types of contraceptives. For some time it was believed that the pills of the last generations may be associated with a lower risk of breast cancer, because they contain smaller doses of hormones, and some of them do not include estrogen. However, the new study took into account which type of contraceptives were used, and the increased risk of breast cancer persisted when taking any type of drugs.

The authors of the work do not urge women to give up hormonal contraception and indicate that in each case it is necessary to weigh the ratio of risks. Hormonal contraceptives are not only one of the most effective contraceptives. Previous studies show that taking such contraceptives reduces the likelihood of developing other cancers, such as endometrial cancer (by an average of 34%) and ovarian cancer (by 33%).

The study was published in the journal New England Journal of Medicine (Mørch et al., Contemporary Hormonal Contraception and the Risk of Breast Cancer).

Previously, researchers have refuted the hypothesis that wearing a bra can increase the risk of breast cancer.

Portal "Eternal youth" http://vechnayamolodost.ru