Breast cancer: Better patient outcomes with current treatments

Breast cancer: Better patient outcomes with current treatments

24 Jul 2015

A class of hormonal drugs called aromatase inhibitors, substantially reduce the risk of death in postmenopausal women with the most common type of breast cancer, a major study of more than 30,000 women shows.

The research underlines the importance of aromatase inhibitors in the treatment of estrogen receptor (ER)-positive breast cancer and shows they reduce risk of death by significantly more than the older hormonal treatment tamoxifen.

Aromatase inhibitors suppress the synthesis of estrogens and are taken by postmenopausal women with hormone-sensitive (ER-positive) breast cancer. They have previously been reported to reduce the risk of recurrence more effectively than tamoxifen, but improvements in survival had not been demonstrated.

Combined results from more than 30.000 women

In the study, researchers from the Aromatase Inhibitors Overview Group, chaired by Professor Mitch Dowsett at The Institute of Cancer Research, London and The Royal Marsden NHS Foundation Trust, collaborated with colleagues at the Clinical Trials Service Unit at The University of Oxford, to combine the results from 31,920 women in nine clinical trials.

Each trial had used both aromatase inhibitors and tamoxifen at various times during the course of treatment.

The current study showed that:

Taking aromatase inhibitors for five years reduced the risk of postmenopausal women/with ER positive breast cancer dying of their disease by 40% within 10 years of starting treatment, compared with no hormonal treatment. This compares with the 30% reduction achieved by taking tamoxifen for five years.

Promising treatment but with important side-effects

Current clinical guidelines reflect the uncertainty in when to use aromatase inhibitors or tamoxifen in the course of treatment – but the new study could help clarify these recommendations.

Study lead author Professor Mitch Dowsett, Head of the Academic Department of Biochemistry and of the Centre for Molecular Pathology at The Royal Marsden and The Institute of Cancer Research, London, said:

“Aromatase inhibitors remove only the tiny amount of estrogen that remains in the circulation of women after the menopause, but that’s enough to have a substantial impact on a wide range of ER-positive tumors, despite their extraordinary differences at the molecular level.

“But aromatase inhibitor treatment is not free of side-effects, and it’s important to ensure that women with significant side-effects are supported to try to continue to take treatment and fully benefit from it.”

Another study also gives hope to patients

The study is published alongside another major breast cancer study of a different drug type, called bisphosphonates.

Commenting on both studies, Nell Barrie, Cancer Research UK’s senior science information manager, said: "These two studies give further evidence that aromatase inhibitors and bisphosphonates, both currently available treatments, help prevent breast cancer coming back in women who have been through the menopause.

“Bisphosphonates help keep bones healthy, and these results show they reduce the chance of breast cancer returning in the bones in post-menopausal women. Aromatase inhibitors block the body's ability to make estrogen, which can fuel the growth of breast cancer, and these results confirm that they can help to stop the disease from returning after treatment.”

These studies supported the recommendation by NICE that the drugs should be first-line hormone treatment for certain women after surgery.

Source: eCancer News