London: Breast cancer deaths can be halved if patients are treated with drug Tamoxifen for 10 years, a new study has revealed.
Researchers say the widely used drug prevents oestrogen fuelling breast cancer in hormone-sensitive patients, the Daily Mail reported.
Daily tamoxifen for five years, which is the current practice, is known to reduce death rates by around a third during the first 15 years after diagnosis.
The new trial, called Atlas, looked at the effect of taking tamoxifen for a total of 10 years after diagnosis.
Researchers recruited almost 7,000 women with oestrogen-sensitive cancer who were completing five years of tamoxifen treatment.
Half stopped their treatment immediately while the remainder continued taking the drug for five more years.
Initially little difference was seen between the two groups, said the scientists. But after 10 years the additional benefits of longer treatment emerged in women who continued taking tamoxifen.
The risk of dying during the second decade after diagnosis was further reduced by about a quarter, leading to a total halving of death rates.
Most of the extra protection occurred after the end of the 10-year treatment period.
“Around three-quarters of all UK women with breast cancer have hormone sensitive disease, and Atlas shows that 10 years of tamoxifen helps save lives not just during the decade women are taking the drug, but also during the second decade after diagnosis,” the paper quoted Atlas trial leader Dr Christina Davies, from Oxford University, as saying.
Tamoxifen is known to increase the risk of womb cancer in post-menopausal women. Atlas showed that the extra risk of dying from this disease due to tamoxifen was two per 1,000 women after five years, and four per 1,000 after 10 years.
The trial findings are published today in The Lancet medical journal.