Anastrozole (Arimidex®) is one of the medications that has been used for years to treat breast cancer in postmenopausal women. The United Kingdom has authorized a new use of this pill, which from now on will also be used to prevent this type of tumors in women with moderate or high risk of developing the disease, as decided by the Medicines and Healthcare products Regulatory Agency (MHRA). ) from this country. According to estimates from the British National Health Service (NHS), around 289,000 women could be included in this risk group.
“This is the first medicine to be repurposed through a new world-leading program to help us harness the full potential of existing medicines into new uses to save and improve more lives in the NHS. Through this initiative, we hope that greater access to anastrozole will allow more women to take steps to reduce their risk if they wish, helping them live without fear of breast cancer,” said Amanda Pritchard, NHS chief executive.
“It’s fantastic that this vital risk-reducing option can now help thousands of women and their families avoid the heartbreak of a breast cancer diagnosis.” “Enabling more women to live healthier, breast cancer-free lives is truly extraordinary, and we hope that licensing anastrozole for a new use today represents the first step in ensuring that it is accessible to all who can benefit from it.” to this risk reduction option,” he added.
This is how Anastrozole works, the pill to prevent breast cancer
Anastrozole is an aromatase inhibitor, which reduces estrogen levels in a woman’s body. In postmenopausal women, estrogen is produced mainly by androgens – sex hormones – converted into estrogens. This conversion is carried out by an enzyme called aromatase, and aromatase inhibitors block this conversion, lowering the level of estrogen in the body. Although estrogen does not cause breast cancer, cancer cells need this hormone to proliferate in estrogen receptor-positive breast cancers, so if estrogen is blocked, cancer cells that feed on this hormone could be unable to survive.
Prophylactic treatment against breast cancer consists of taking a 1 mg anastrozole tablet once a day for five years. Each pill costs less than five cents. However, this medication has side effects that may prevent some women from completing treatment. The most common adverse effects are hot flashes, weakness, joint pain or stiffness, arthritis, rash, nausea, headache, osteoporosis, and depression.
This preventive treatment against breast cancer consists of taking a 1 mg tablet of anastrozole daily for five years
The decision to use the drug as a preventive treatment, as reported by the MHRA, is based on the evidence provided by the IBIS-II study, an international, randomized, double-blind, placebo-controlled trial, which showed that women receiving anastrazole developed fewer breast tumors than those in the placebo group. The IBIS-II study was published in 2019 in The Lancet, with Jack Cuzick of Queen Mary University of London as lead author.
The results published then were based on data from 3,864 study participants, of whom 1,920 received anastrazole for five years, and 1,944 received placebo. The model to determine the level of risk of hormonal cancer in women took into account factors such as family history, breast density, obesity, alcohol consumption and a premalignant lesion, among others.
Follow-up lasted for 12 years, with a median of 10.9 years. At 12 years (seven after stopping treatment), the incidence of breast cancer was found to be 49% lower in women who took the drug than in those who received a placebo.
Adherence during the five years the pills were taken was 77% in the placebo group and 74.6% in the anastrozole group, suggesting that the side effects were not severe enough to stop the drug. medication. In fact, researchers have indicated that there were no significant long-term side effects in the years following the end of anastrozole treatment, especially an increase in bone fractures or the development of diseases.
