Senior Health Report -- Health News for Seniors About Breast Cancer

Post-menopausal breast cancer patients who switched to Aromasin after two to three years of tamoxifen were 17 percent more likely to be alive and 25 percent less likely to have a cancer recurrence than patients who continued on tamoxifen for a full 5 years, according to British researchers.

The results of a five-year trial of Aromasin, presented at the annual scientific meeting of the American Society of Clinical Oncology, provide the first proof of benefit to women who switch to one of the new breed of drugs called aromatase inhibitors after starting on the current treatment, tamoxifen.

The researchers looked at 2,352 postmenopausal women with early-stage breast cancer who switched to Aromasin after two to three years of treatment with what has been the "gold standard" hormone-blocking drug tamoxifen, and compared them to 2,372 treated with tamoxifen alone.

They found the risk of dying after five years was 6.6 percent for women who took the two drugs in sequence, compared with a death rate of 8.3 percent for women who took tamoxifen for the full five years and 11.9 percent for women who took no drugs at all.

The new drug also cut the risk of the cancer spreading by 17 percent and lowered the incidence of tumors in the opposite breast by 44 percent. The overall risk of any breast cancer recurrence or any new breast cancer was reduced by 24 percent.

Last month, Britain's National Institute for Health and Clinical Excellence (Nice) provisionally recommended the use of aromatase inhibitors -- which include Arimidex and Femara -- alongside tamoxifen but said there was no evidence the new drugs could improve survival.

The new data, from the Intergroup Exemestane Study, provides the first proof that women live longer when their treatment includes an aromatase inhibitor.

"We're talking about many hundreds of potential lives being saved purely by switching drugs at this early stage," said Mary McCormack, a consultant clinical oncologist at University College hospital in London. "We think up to a thousand."