In a new study, researchers have found how using hormonal contraceptive can increase risk of breast cancer. The most commonly used contraceptive is the progestin- only birth control pills and the research found that using the progestin-only contraceptive can increase breast cancer risk similarly as the combined contraceptives. Contraceptive pills are of 2 types: the progestin -only pill and the combined pill containing both progestin and estrogen based ingredients.

Between 2017 and 2019 around 65% women of the age 15 to 49 were using some sort of contraception and 14% of them were using the pill. Progestin or progesterone is a synthetic version of progesterone which is a naturally occurring hormone. A meta-analysis from 1996 showed that people taking combined contraceptives have a slightly increased risk of breast cancer within 10 years of using. The progestin-only methods of contraception include pills, injectables, intrauterine devices (IUDs) and implants.

For the study researchers analyzed health records from a UK primary care database and took data from 9,498 women aged under 50 years with breast cancer and 18,171 women who don’t have it and altogether 44% of women had breast cancer and 39% of those who don’t had a prescription for hormonal contraceptives and half of these were for progestin-only contraception. It was found that combined pill increased breast cancer risk by 23% and oral progestin- only contraceptive pills increased breast cancer risk by 29%. Researchers added that 5 years of oral contraceptive use was linked to breast cancer incidence in 8 per 100,000 users aged 16-20 years old and incidence of 265 per 100,000 users aged 35-39 years old.

Dr. Parvin Peddi not involved in the study stated that “on the other hand it is important to note that the absolute increased risk of breast cancer from any of these medications is quite low and this study should not dissuade women from using hormone containing birth controls” she also added “risk of breast cancer was seen in less than 0.5% of women age 35-39 years old due to use of these medications and in even fewer women who used these medications at a younger age.”