“The pill” increases breast cancer risk for some
31 October 2024
A Peter Mac-led study has provided an answer on whether taking a hormonal contraceptive further increases risk for women who already have elevated lifetime risk of breast cancer.
The study took in data from almost 5,400 women with a BRCA1 or BRCA2 gene mutation, and who had joined one of several major longitudinal studies which tracked their health over time.
None had cancer when they joined these studies and there was common use of “the pill” (mini and combined) or other hormonal contraceptives (implants, injections, intrauterine devices).
Among 3,882 women with a BRCA1 mutation, 53% had used a hormonal contraceptive for at least a year and 488 went on to develop breast cancer.
Professor Kelly-Anne Phillips led the research“Hormonal contraceptives were associated with increased breast cancer risk for BRCA1 mutation carriers, especially if used for longer durations,” says Peter Mac’s Professor Kelly-Anne Phillips.
“Decisions about their use in women with BRCA1 mutations should carefully weigh the risks and benefits for each individual.”
The results for BRCA2 mutation carriers were inconclusive and while Prof Phillips said there was no evidence of increased risk, more research was warranted.
Hormonal contraceptives are some of world’s most commonly prescribed medications, and Prof Phillips said they otherwise provide excellent contraception and can have other health benefits.
Her paper titled “Hormonal Contraception and Breast Cancer Risk for carriers of Germline mutations in BRCA1 and BRCA2” published earlier this month in the Journal of Clinical Oncology.
October is also Australia’s Breast Cancer Awareness Month, and did you know:
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Breast cancer is the most common cancer affecting Australian women.
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This year 20,973 women and 221 men were expected to be diagnosed with breast cancer.
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The BRCA1 and BRCA2 genes help protect against this cancer and people who inherit an abnormal version of these genes have elevated lifetime risk.
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These gene abnormalities occur in just 0.2% of the Australian population however BRCA1 or BRCA2 mutations account for about 5% of all breast cancer cases.
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Overall, breast cancer survival is improving. Between 1989–1993 and 2014–2018, five-year relative survival for breast cancer improved from 77% to 92%.
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Peter Mac has an online tool called “iPrevent” you can use to better understand your personal risk of breast cancer. Go to: www.petermac.org/iprevent