Women most at risk of developing breast cancer will be offered a pill that halves their risk of developing the disease.
NHS England and UK medicines watchdogs announced that the pill anastrozole will now be offered as a cancer preventative thanks to a new approval process that repurposes old drugs for new uses.
Health service chief executive Amanda Pritchard said: “It is fantastic that this vital risk-reducing option can now help thousands of women and their families avoid the distress of a breast cancer diagnosis.”
Women already taking the drug have described it as a “gift” that allows them to get on with their lives with less worry about a possible cancer diagnosis.
But what exactly is anastrozole? Who is eligible? And are there any side effects?
Here, MailOnline answers all your questions…
Traditionally, anastrozole has been used as a treatment for women suffering from breast cancer. But trials have found that hormone therapy can also cut a woman’s chances of developing it in half.
What is anastrozole and how does it work?
Anastrozole is a hormone therapy medication that has been used for years in the treatment of breast cancer.
It works by reducing the amount of aromatase that the body can produce. After women go through menopause, this enzyme is vital for the production of estrogen.
This reduces the risk of breast cancer, as estrogen drives the growth of some versions of the disease.
What has happened?
While anastrozole has been used as a breast cancer medication for years, doctors can now easily prescribe it as a cancer preventative.
The preventive benefits of the drug have been known since 2017.
However, obstacles had to be overcome before it could be offered for this use.
After AstraZeneca’s patent on anastrozole expired, it became a generic drug, meaning it could be made by any drug manufacturer, a process that generally makes drugs cheaper.
However, it also leaves little incentive for companies to take the necessary steps to obtain approval of a generic drug for another medical use (in this case, cancer prevention rather than treatment).
However, the Great Britain Medicines Repurposing Programme, created in 2021 by the NHS, the Government and the UK’s medicines and treatment regulators, takes charge of this process.
A small number of women were previously prescribed the drug as a cancer preventative “off-label,” meaning doctors were prescribing it outside of its officially approved use.
But the new official approval is expected to make it easier for more women to get it – NHS bosses say around 289,000 women will be eligible.
How effective is it in preventing cancer?
According to clinical trials, breast cancer cases were reduced by 49 percent among women at high risk of developing breast cancer who took anastrozole.
The study followed 4,000 postmenopausal women for 10 years and found that the reduced risk of breast cancer persisted even when the women stopped taking the drug.
Breast cancer is most commonly diagnosed in women over 50 who have gone through the menopause and accounts for 80 per cent of all cases in the UK.
How often should patients take it?
Anastrozole is taken in daily tablet form.
Women who are prescribed the drug for breast cancer prevention will take it for five years between ages 50 and 69.
Who will be eligible to receive the medication?
The NHS says around 289,000 women at moderate or high risk of breast cancer aged 50 to 69 could be eligible for the drug.
Women will be classified as moderate risk if they have a close relative, such as a mother, sister or daughter, who has breast cancer.
Their risk of developing the disease is about one in six, compared to one in seven among the general population.
Women are considered high risk if two close relatives or one close relative and a second, more distant relative, such as a grandmother or aunt, have breast cancer.
Your chance of developing the disease is one in three.
Women are expected to be offered anastrozole after seeing their GP, who will examine their family history. However, this process may involve additional consultation with a specialist.
What are the side effects?
The most common side effects are symptoms similar to those of menopause.
More than one percent of women taking the drug will experience hot flashes, difficulty sleeping, tiredness and low mood, as well as vaginal dryness or itching, mild aches and pains, and hair loss or thinning.
However, these side effects usually improve in the first few months of taking anastrozole.
Serious side effects occur in fewer than one in 100 women who take the drug. These include painful or swollen muscles and joints, liver problems, and blurred vision.
How many lives could it save?
There are no specific estimates for this.
But the NHS says that even if just a quarter of eligible women took up the offer of the drug, 2,000 cases of breast cancer would be prevented.
While not all of these would necessarily be fatal, they will prevent these women from having to undergo treatments such as surgery or grueling chemotherapy.
Breast cancer kills around 11,500 Britons a year, making it the fourth leading cause of cancer death in the UK.
Specifically for women, breast cancer is the second leading cause of death among all versions of the disease.
Why does the NHS believe that not all women eligible to receive it will take the drug?
This is probably due to side effects.
Some women will be more susceptible to them than others, or will suffer more severe symptoms while taking the medication, so they may choose to stop taking it.
Additionally, since anastrozole is a cancer preventative, there will be no evidence that a woman taking the drug has prevented her from developing breast cancer.
Considering that even a woman at high risk of developing breast cancer has a better chance of avoiding the disease than of receiving a cancer diagnosis, some women may decide that taking the drug for five years is not worth it.
How much does the medicine cost?
Anastrozole costs just 4p per tablet, meaning a five-year treatment costs a total of £70.
It would cost 72,250 women £5.3m to take the drug over five years.