Better breast cancer treatments
Two separate studies find improvements to existing breast cancer treatments
6th December 2012 - New breast cancer studies have found that doubling the amount of time women stay on the drug tamoxifen and having fewer but larger doses of radiotherapy could well be the way forward when it comes to tackling the disease.
Around three-quarters of women with breast cancer in the UK are diagnosed with oestrogen-receptor positive (ER+) form of the disease, which is driven by the female hormone, oestrogen. After any surgery, radiotherapy or chemotherapy, many women receive some years of treatment with a drug like tamoxifen or with an aromatase inhibitor, to prevent any remaining cancer cells being 're-fuelled' by oestrogen.
The current standard duration of treatment with tamoxifen is for it to be taken daily for five years after the cancer has been surgically removed. This is already known to reduce death rates by around a third throughout the first 15 years after diagnosis, as the protective effects continue for at least a decade after the five years of treatment has ended.
The new study (the ATLAS trial) was carried out by an international group of researchers, led by Dr Christina Davies of the Clinical Trial Service Unit and Epidemiological Studies Unit at the University of Oxford. The results have been published in The Lancet and found that doubling the time that breast cancer patients take tamoxifen cuts the risk that the cancer will come back and further lowers the risk of dying of the disease.
The study compared nearly 7,000 women with early-stage, oestrogen-sensitive breast cancers. Early-stage cancers were considered to be any cases in which all detected disease could be completely removed.
About half the women in the study stopped taking tamoxifen after the recommended five years, while the other half took the drug for 10 years.
Over the next 10 years, 1,328 women in the study saw their cancer recur. There were 617 recurrences in the group that took tamoxifen for 10 years compared to 711 among women who took the drug for five years. Overall, women who stayed on tamoxifen cut their risk of having cancer come back from 25.1% to 21.4%.
There were also fewer deaths from breast cancer in the group the group that stayed on tamoxifen -- 12.2% in the 10-year group compared to 15% in the five year group.
Martin Ledwick, Cancer Research UK's head information nurse, said in a press release: "This important study adds further clarity to the question about the length of time women should take tamoxifen. Although treatment for hormone receptor positive breast cancer has become more complex in recent years with some women receiving aromatase inhibitors, these results will help in deciding the length of treatment for women who are prescribed tamoxifen alone."
Experts who were not involved in the study said it was likely to have a limited application, partly because newer drugs have displaced tamoxifen in older women and partly because it can be a difficult drug to take.