How worried should we really be about the Pill and breast cancer? As Oxford scientists find all forms of hormonal contraceptives increase a woman’s risk by up to a third, experts answer your most pressing questions
- The study stated that progestogen-only forms of contraception could increase a woman’s chance of developing breast cancer by up to 30 per cent
- Researchers analysed data from more than 27,000 women: a third of whom developed breast cancer between ages of 20 and 49, and two-thirds who didn’t
Just a little pill, popped out of a packet, placed on the tongue — and swallowed with barely a second thought.
It’s a daily ritual for 100 million women worldwide, and a third of British women currently using contraception, who still — 62 years after its invention — rely on the Pill to control their reproductive cycle.
But a major study by the University of Oxford has sparked concern after it linked progestogen-only forms with a heightened risk of breast cancer, stating it could increase a woman’s chance of developing the disease by up to 30 per cent.
So are you at risk? Should you stop taking the Pill? And what are the alternatives?
Here, SARAH RAINEY addresses key questions about the study…
It’s a daily ritual for 100 million women worldwide, and a third of British women currently using contraception, rely on the Pill to control their reproductive cycle. But a major study by the University of Oxford has sparked concern after it linked progestogen-only forms with a heightened risk of breast cancer, stating it could increase a woman’s chance of developing the disease by up to 30 per cent (file photo)
WHAT DO I NEED TO KNOW ABOUT THE STUDY?
Researchers analysed data from more than 27,000 women: a third of whom developed breast cancer between the ages of 20 and 49, and two-thirds who didn’t.
Over a 15-year period, they found a link between those who were taking — or had recently stopped taking — the progestogen-based contraceptive pill — and those who developed breast cancer.
The increased likelihood of a cancer diagnosis was as high as 20 to 30 per cent.
WHICH TYPES ARE UNDER SCRUTINY?
There are two types of oral contraception: the combined Pill (which contains synthetic versions of both oestrogen and progestogen, the two female hormones that are found naturally in the ovaries) and progestogen-only.
The latter used to be less popular, but interest is growing — due to fewer side-effects — and now NHS prescriptions for both stand at around three million.
This study focused on progestogen-based contraception, also known as the ‘mini Pill’ or ‘progestogen-only’.
However, research has previously linked the combined Pill with an increased risk of breast cancer. Experts say the likelihood is around the same for both.
ARE COILS/IMPLANTS A CONCERN?
The new research applies to whatever form of hormonal contraception you use: whether oral, implant or injection — all of which release progestogen into the body.
If you have the coil, however, it depends which type.
Women with a traditional copper coil (also called an ‘IUD’ or ‘intra-uterine device’) aren’t affected because these release copper, not hormones, to impede sperm movement and prevent pregnancy.
If you have an IUS — ‘intra-uterine system’ — however, the new research does apply. This more modern, plastic device works by releasing progestogen.
Researchers found the cancer risk factor to be slightly higher — 32 per cent — for women with an IUS compared with other forms of hormonal contraception.
WHAT ABOUT THE PILL I CAN BUY?
Since July 2021, progestogen-only contraception has been on sale at pharmacies and online.
This applies only to pills containing desogestrel, a substance which stops a woman’s eggs from forming properly. Whether you get your pills over the counter or on prescription, the risk is the same.
AM I AFFECTED IF I’M TAKING HRT?
The study didn’t look at HRT — hormone replacement therapy —taken by around 15 per cent of women aged 45 to 64 to counteract symptoms of the menopause.
However, Oxford experts suggest that it, too, many be covered by the results.
Combined HRT contains both oestrogen and progestogen and has previously been linked — in a 2021 study of 99,000 women — with an increased risk of breast cancer while women are taking it.
Oestrogen-only HRT (used by women who’ve had a hysterectomy) contains no progestogen, so the latest research doesn’t apply.
Still, earlier research has shown a very small link between long-term use of oestrogen-only HRT and breast cancer.
Researchers analysed data from more than 27,000 women: a third of whom developed breast cancer between the ages of 20 and 49, and two-thirds who didn’t (pictured, file photo of the copper coil)
SO HOW BIG IS THE RISK IN REALITY?
An increased risk of 20-30 per cent of developing breast cancer may sound high, but experts insist that there is no cause for alarm.
Dr Susan Walker, an associate professor in contraception, reproduction and sexual health at Anglia Ruskin University, describes the link as a ‘small increased risk’.
Other experts say there are limitations to the latest research. Dr Kotryna Temcinaite, of the charity Breast Cancer Now, explains: ‘The study didn’t look at which hormonal contraceptives the women may have used in the past or consider how long they may have been on progestogen-only contraception.
‘It also didn’t factor in whether a family history of the disease contributed to their level of risk.’
Nor does the study compare the statistic to other risk factors for breast cancer, which include obesity, drinking, smoking and being physically inactive.
Dr Walker explains: ‘The risk related to use of hormonal contraceptives is similar to the risk associated with being overweight or drinking alcohol.’
In numerical terms, for every 100,000 women aged 16-20 who use progestogen-only contraception there are an extra eight cases of breast cancer; and for those aged 35 to 39, there will be around 265 extra cases in 100,000.
IS THIS THE FIRST CANCER SCARE?
No. Several studies have linked the Pill with cancer, both positively and negatively. Since the 1990s, the combined Pill has been linked with a higher incidence of breast cancer, and this research suggests it can increase the risk by around 25 per cent.
According to Cancer Research UK, there is also a slight increased risk of developing cervical cancer on the combined Pill, which increases the longer it is taken.
However, there is a more positive link. ‘The combined Pill decreases the risk of ovarian and endometrial cancer by 40-50 per cent,’ says Dr Walker. It has also been shown to reduce the likelihood of developing bowel cancer by 19 per cent.
HOW LONG DOES THE RISK LAST?
Once women stop taking the progestogen-only Pill, the study suggests, their cancer risk starts to drop. Within a year, it could still be as high as 33 per cent say the Oxford researchers. Between one and four years later, however, it drops to 17 per cent, and after five years it’s 15 per cent.
Your increased risk will, ultimately, disappear completely.
‘The study indicated the risk returns to normal ten years after stopping the hormonal method,’ says Dr Walker.
WHAT ABOUT ANY HORMONE BENEFITS?
Kirstin Pirie, one of the lead authors of the study, says it’s important to see the findings ‘in the context of the well-established benefits of contraceptive use’. First, there’s the proven reduced risk of ovarian, endometrial and bowel cancer in women who take the combined Pill.
Dr Walker says: ‘This is important because ovarian cancer in particular is a condition which is often undiscovered until it has reached a very late stage.’ Hormonal contraceptives enable women to regulate their menstrual cycles, alleviate painful periods, prevent anaemia and relieve symptoms of endometriosis, a condition which affects uterine tissue.
DOES IT MATTER HOW LONG I’VE TAKEN IT?
The study was based on GP records, which start only once a woman joins a particular practice — meaning the data was short- and not long-term. The researchers specifically looked at women who’d been taking the Pill for five years. But most women are on it for far longer — sometimes up to four or five times this.
Experts say it’s impossible to determine whether longer-term use means a higher risk without further studies — but the answer may well be yes. A similar piece of research into HRT, published in the BMJ in 2021, found that cancer risks in women were higher if they’d been taking it for more than five years.
DOES MY AGE HAVE BEARING ON RISK?
‘Age certainly matters,’ says Dr Walker, ‘because what the studies showed was that the underlying risk of breast cancer is multiplied by a factor of 1.2 to 1.3.
‘If the underlying risk is very small, as is the case with younger women, then this multiplication of risk does not cause much of an increase in absolute or real risk.
‘But if the underlying risk is larger, which it becomes as women get older, then this multiplication can increase the absolute risk by a greater amount.’
According to Cancer Research UK, average breast cancer rates in this country range from 2 cases in every 100,000 in women aged 20 to 24 up to 4,974 cases per 100,000 in women aged 45-49 (the oldest group in the recent study). The older you are, the greater your initial risk — so the greater your increased risk.
Over a 15-year period, they found a link between those who were taking — or had recently stopped taking — the progestogen-based contraceptive pill — and those who developed breast cancer (pictured, file photo of a contraceptive patch)
SO SHOULD I STOP TAKING IT?
No, says Prof Gillian Reeves of the Cancer Epidemiology Unit at Oxford University. ‘I don’t really see that there’s any indication here to say that women need to necessarily change what they’re doing.’
The purpose of the research, she adds, was to ‘fill a gap’ in scientific knowledge about the progestogen-only Pill — which experts already suspected to be just as much of a risk factor as the combined Pill. It remains your choice, in consultation with your doctor, about which — if any — contraception you take.
ARE THERE ANY ALTERNATIVES?
If you want to avoid hormonal contraception completely, there are several options. There’s the barrier method, including male or female condoms, or the diaphragm or ‘cap’, used in conjunction with sperm-neutralising gel, all of which prevent semen from getting into the vagina.
There has been a recent resurgence in natural family planning, also known as the ‘rhythm method’, which involves couples avoiding sex on a women’s most fertile days in the lead-up to and just after ovulation.
This requires daily temperature readings and monitoring a woman’s cervical secretions, often with the aid of a smartphone app, but is viewed with some scepticism by experts.
Finally, there’s the much-anticipated male Pill — currently still under research but with several promising trials — which could be available within a decade, removing the contraceptive burden from women once and for all.
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