Most of the 40,000 women a year in the United Kingdom with the commonest form of cancer, known as oestrogen receptor positive, are prescribed aromatase inhibitors if they are postmenopausal and the older British drug tamoxifen if they have not reached the menopause. Doubling the duration of hormone therapy for women with early-stage breast cancer from five to 10 years reduces the risk of recurrence and developing tumours in the other breast, a study showed yesterday.
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Shona Robison, Scottish Health Secretary, said: “Our £450,000 joint partnership with Breast Cancer Now will allow for more Scottish-led research into breast cancer development to take place, helping to further enhance our knowledge and treatment of the disease”.
Dr Nick Turner, a breast cancer specialist from the Institute of Cancer Research in London, told the BBC News website: “It is a big deal, it’s going to be a change of treatment for a lot women. Prof Paul Goss, one of the researchers from Massachusetts General Hospital, said: “[The study] will have an enormous impact, a reduction in recurrences is a very important finding. “Future studies may better identify women for which metformin may be most beneficial, as well as the most effective dosing regimens”, she said.
He said: “In general, I would imagine that women who had riskier cancers will look to these data and think they are compelling for continuing on longer durations of treatment out to 10 or 15 years”.
“The important thing is that the AIs should be extended beyond five years to 10 years”, he said, adding that women reported no worse quality of life when taking the drugs for longer.
The research team conducted the trial in post-menopausal women, who were asked to undergo the aromatase inhibitor treatment for 10 years rather than 5.
While there were differences in how many women had their cancer return, and who therefore needed more treatment, there was no overall difference between the groups in how long women lived.
The researchers based their conclusion on the results of a clinical trial involving more than 1,900 breast cancer patients.
Those side effects, as well as the absence of a survival benefit, means doctors and patients will have to carefully weigh the risks and benefits of taking an aromatase inhibitor for a decade, said Leonard Lichtenfeld, deputy chief medical officer for the American Cancer Society who wasn’t involved in the research. It was also discovered that by the end of the study, 95% of women were still cancer-free if they would have continued taking extra medication, while the percentage for those not taking were 91%. Such tumors linked to estrogen have low, yet the persistent risk of returning after a few years. It enrolled 1,918 women, some of whom took an aromatase inhibitor called letrozole for 10 years, while the rest were given placebo pills.
Research suggests cancer patients can survive with shorter bursts of radiotherapy. The most common site of recurrence was distant: 42 in patients treated with Femara versus 53 in the placebo arm, followed by bone (28 vs 37, respectively) and locoregional (19 vs 30, respectively). The researchers divided the participants into two groups.
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“Using metformin as a cancer prevention strategy has been controversial and results have been inconsistent, but our analysis reveals that use of the drug is time-dependent, which may explain the disparity”.
