Two different classes of drugs, aromatase inhibitors and bisphosphonates, can improve survival prospects for postmenopausal women with early breast cancer, suggests latest research.
In addition, researchers suggest that the two types of drug can be used together, increasing the benefits while also decreasing some side-effects.
“These studies provide really good evidence that both of these inexpensive, generic drugs can help to reduce breast cancer mortality in postmenopausal women”
Two studies, published today in The Lancet, provide the best evidence yet for the effects of aromatase inhibitors and bisphosphonates on postmenopausal women with early breast cancer.
One study brings together evidence from 30,000 postmenopausal women in nine trials, showing that five years of treatment with the newer endocrine therapy – aromatase inhibitors – produces better survival than standard endocrine therapy with tamoxifen.
Compared to tamoxifen, taking aromatase inhibitors for five years further reduced the likelihood of the cancer recurring by 30% and the risk of dying from breast cancer by around 15% throughout the decade after beginning treatment.
The second study included evidence from 20,000 women in 26 trials. It showed that two to five years of treatment with bisphosphonates – usually used to treat osteoporosis – reduced the risk of breast cancer recurring in post-menopausal women, and also significantly extends survival.
Among postmenopausal women, bisphosphonate treatment produced a larger reduction in bone tumour recurrence of 28% and also reduced the risk of dying from breast cancer by 18% during the first decade after diagnosis.
“This is one of the most important steps forward in breast cancer treatment since the introduction of Herceptin over 10 years ago”
Bisphosphonates alter the bone microenvironment, which could make it less favourable for cancer cells and so reduce the risk of cancer recurrence in the bone and in other organs, suggested the study authors.
Professor Richard Gray, from Oxford University, was the lead statistician for both studies. He said: “These studies provide really good evidence that both of these inexpensive, generic drugs can help to reduce breast cancer mortality in postmenopausal women.
“About two-thirds of all women with breast cancer are postmenopausal with hormone-sensitive tumours, so could potentially benefit from both drugs,” he said.
He added: “The drugs are complementary, because the main side effect of aromatase inhibitors is an increase in bone loss and fractures, while bisphosphonates reduce bone loss and fractures as well as improving survival.”
Both studies were funded by Cancer Research UK and the UK Medical Research Council.
Baroness Delyth Morgan, chief executive of the charity Breast Cancer Now, especially welcomed the findings on bisphosphonates.
“We believe that this is one of the most important steps forward in breast cancer treatment since the introduction of Herceptin over 10 years ago,” she said. “But this time we’re talking about a few pence rather than thousands of pounds, and millions saved by the NHS.”
However, Baroness Morgan noted that the cheapness of the drugs meant there was “no commercial incentive” to license the drugs for the new indication.
“That’s why we want to see the governments and the regulatory bodies across the devolved nations, and the NHS make it a priority to look at ways in which they can support the routine availability of these low-cost, life-saving treatments,” she said.
“Given the minimal cost, surely this is exactly the type of money-saving opportunity the cash-strapped NHS can’t afford to miss,” she added.