CONTRACEPTIVE pills increase the risk of breast cancer by up to 30 per cent, a study found.
The added risk is still tiny — less than 0.3 per cent — but above average for users of the newer progestogen-only “mini pill” as well as those who take the older combined pill.
GettyContraceptive pills increase the risky of breast cancer between 20 and 30 per cent, a study by Oxford University found[/caption]
Oxford University scientists said the risks were substantially higher in older women than those in their teens and 20s.
While the chances of developing cancer on the combined contraceptive were well-known, the new research provides fresh insight into the newer pill.
Study author Kirstin Pirie said the risks should be weighed against the “well-established benefits” of contraception.
She said: “All types of progestogen-only contraceptives are associated with a slight increase in breast cancer risk, similar to that of combined oral contraceptives.
“Absolute excess risk associated with use of either type of oral contraceptive will be smaller in women who use it at younger rather than at older ages.”
Around 27 per cent of women were prescribed contraceptive pills by NHS Sexual and Reproductive Health Services in 2021/22.
Separate studies show the proportion of women taking progestogen-only pills increased from 4.3 per cent in 2000 to 10.8 per cent in 2018 in the UK.
During the same period, the figure fell from 26.2 per cent to 14.3 per cent for combined hormonal contraception.
The combined pill uses two hormones — oestrogen and progesterone — to stop the ovaries releasing an egg each month, and is 99.7 per cent effective against pregnancy.
In contrast, the progestogen-only pill only contains one hormone and causes cervical mucus to thicken, preventing sperm from entering the womb, with a similar level of effectiveness.
Both pills can cause a variety of side effects, including tender breasts and feeling sick, and can also affect body weight, mood and libido in some women.
Doctors may discourage combined pills if you have a history of breast cancer.
The link between the pill and the disease is poorly understood, but the hormones used in them have been shown to increase the risk of some breast cancers.
What are the symptoms of breast cancer?
The first symptom of breast cancer that most women notice is a lump or an area of thickened tissue in their breast.
Most breast lumps are not cancerous, but it’s always best to have them checked by a doctor.
You should see a GP if you notice any of the following:
a new lump or area of thickened tissue in either breast that was not there before
a change in the size or shape of one or both breasts
a discharge of fluid from either of your nipples
a lump or swelling in either of your armpits
a change in the look or feel of your skin, such as puckering or dimpling, a rash or redness
a rash (like eczema), crusting, scaly or itchy skin or redness on or around your nipple
a change in the appearance of your nipple, such as becoming sunken into your breast
Breast pain is not usually a symptom of breast cancer.
Source: The NHS
The latest study, published in PLOS Medicine, compared how the two pills impact the risk of the disease.
Researchers tracked contraceptive use in nearly 10,000 under-50s with breast cancer from 1996 to 2017.
They were compared to just over 18,000 disease-free women.
Women taking either pill were between 20 to 30 per cent more likely to develop breast cancer.
Using either for five years increased cases by 8 per 100,000 for women aged 16 to 20 and 265 per 100,00 for 35- to 39-year-olds.
Dr Kotryna Temcinaite, of Breast Cancer Now, said: “There is a small increased risk of developing breast cancer for women while they are using a progesterone-only contraceptive.
“For both types of contraceptives, if you stop using them, this added risk of breast cancer reduces over time.”
She added: “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.”