Two Generics Reduce Breast Cancer Deaths, Studies Find

Two inexpensive generic drugs have been shown to reduce breast cancer deaths in postmenopausal women, according to studies published in The Lancet.

In one study of aromatase inhibitors (AIs), researchers analysed results of 30,000 menopausal women in 9 randomized trials and determined that 5 years of treatment with a newer endocrine therapy, like AIs, produces a better survival than treatment with a standard endocrine therapy, such as tamoxifen.

Women who took AIs for 5 years further reduced their likelihood of breast cancer recurrence by 30% and the risk of death from the cancer by approximately 15%.

“The impact of aromatase inhibitors is particularly remarkable given how specific these drugs are—removing only the tiny amount of oestrogen that remains in the circulation of women after the menopause—and given the extraordinary molecular differences between ER-positive tumours,” lead author Mitch Dowsett, FMedSci, PhD, of The Royal Marsden and The Institute of Cancer Research, said in a statement. “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.”

In the second study, researchers analysed evidence from another 20,000 women in 26 randomized trials and found that taking bisphosphonates for 2 to 5 years reduced the risk of breast cancer recurring in post-menopausal women and significantly extended survival. This class of drug seems to have little effect on premenopausal women. Overall, there was a 17% reduction in recurrence of cancer in the bone, but in postmenopausal women only the reduction was 28%.

According to the lead author of this study, since these treatments are well tolerated they should be considered routine use in treatment of early breast cancer in women with menopause. In addition, AIs and bisphosphonates are complementary treatments since the main side effect of AIs is an increase in bone loss and fractures, while bisphosphonates reduce bone loss and fractures.

“These studies provide really good evidence that both of these inexpensive, generic drugs can help to reduce breast cancer mortality in postmenopausal women,” Richard Gray, MA MSc, lead statistician for both studies and a professor at the University of Oxford, said. “About two-thirds of all women with breast cancer are postmenopausal with hormone-sensitive tumors, so could potentially benefit from both drugs.