Bone drug can prevent breast cancer

A WIDELY-USED bone drug can prevent breast cancer and is safer and just as effective for post-menopausal women as tamoxifen, a study has shown.

At least two million women might benefit from raloxifene's cancer-reducing effects, US researchers said.

Until now, the decades-old tamoxifen has been doctors' only choice to reduce the chances of breast cancer striking high-risk women.

Manufacturer Eli Lilly already sells raloxifene, under the brand name Evista, to combat bone-thinning osteoporosis, another disease common after menopause.

Armed with the new study of nearly 20,000 women, Lilly now plans to seek Food and Drug Administration approval to market raloxifene as a cancer-preventer too.

Both drugs are "selective oestrogen response modulators" they act like the oestrogen hormone in some tissues, but like an anti-oestrogen in others.

Oestrogen can fuel certain breast cancers. But by acting like an oestrogen in the uterus and bloodstream, tamoxifen causes some rare but serious side effects, increasing users' risk of getting uterine cancer or a life-threatening blood clot.

Raloxifene is a close chemical relative. The National Cancer Institute (NCI) study found that taking either tamoxifen or raloxifene daily for up to five years cut in half women's chances of developing invasive breast cancer.

Raloxifene causes the same side effects, but not as many: Raloxifene users had 36% fewer uterine cancers and 29% fewer blood clots.