Breast cancer risk may increase with hormonal contraceptive use

The study indicates that the use of progestogen-only hormonal contraceptives is associated with a 20-30% higher risk of breast cancer.

Previous studies found that use of the combined contraceptive pill, which combines oestrogen and progestogen, is associated with a small increase in the risk of developing breast cancer that declines after stopping use.

According to the new findings, the absolute excess risk of developing breast cancer over a 15-year period in women with five years of use ranged from eight in 100,000 women for use from age 16 to 20 to 265 in 100,000 for use from age 35 to 39.

Excess risk for breast cancer increased slightly through the age groups who use contraceptives which combines oestrogen and progestogen

Women don't need to 'necessarily change' what they're doing

Gillian Reeves, Professor of statistical epidemiology and director of the Cancer Epidemiology Unit at the University of Oxford, was part of the research team.

When discussing the findings she said there should not be too much concern, and that women don't "need to necessarily change what they’re doing".

She added: "Yes, there is an increase here, and yes, nobody wants to hear that something that they’re taking is going to increase their risk for breast cancer by 25%.

“The main purpose of doing this research was really to fill a gap in our knowledge.

“We’ve known for many years that combined oral contraceptives, which women have been using for decades, also have an effect on breast cancer risk, a small increase in risk which is transient.

“We weren’t absolutely sure what the corresponding effect of these progestogen-only contraceptives would be.

“What we’ve shown is that they’re just the same in terms of breast cancer risk, they seem to have a very similar effect to the other contraceptives, and the effect that we’ve known about for many years.

The research should not cause too much concern, academics have said (Image: PA)

“I suspect that if women were prepared to accept those risks in the past, in return for the many benefits of taking hormonal contraceptives, then they may well be prepared to carry on doing that.”.

Why was the research conducted?

The research suggests use of progestogen-only contraceptives has increased substantially in recent years, but information on their association with breast cancer risk was limited.

In 2020, there were almost as many prescriptions issued in England for progestogen-only oral contraceptives as there were for the combined pill.

Dr Kotryna Temcinaite, head of research communications at Breast Cancer Now, said: “For both types of contraceptives, if you stop using them, this added risk of breast cancer reduces over time.

“The study didn’t look at what hormonal contraceptives the women may have used in the past or consider how long they may have been on the progestogen-only contraception.

“It also didn’t factor in whether a family history of the disease contributed to their level of risk. So further work is needed to help us fully understand the impact of using this type of contraception.

“Breast cancer is rare in young women. A slight increase in risk during the time a woman uses hormonal contraceptive means only a small number of extra cases of the disease are diagnosed.”