Estrogen-only therapy may prevent breast cancer in some women

The estrogen-only hormone replacement therapy may be younger postmenopausal women without a uterus of a benefit, a Canadian researcher said Thursday at the annual meeting of the Symposium in San Antonio Breast Cancer.

Dr. Joseph Ragaz, an oncologist at the University of British Columbia, presented a new analysis of the Initiative on the health of women - which originally concluded that both long-term estrogen alone and estrogen plus progestin hormone replacement have been too risky for most women.

But Ragaz said his analysis of the data suggest that use of estrogen alone - for women without a uterus and do not need progestin - protects against breast cancer. He found that subsets of women, postmenopausal women and young people with no family history of breast cancer or benign breast disease, a lower risk of breast cancer after use of estrogen and reaped the benefits health, such as, for example, a lower risk of heart disease.

Ragaz said that studies are needed to determine whether estrogen produced by the body, called endogenous estrogen and known to fuel cancer growth and external sources of estrogen (called exogenous) have different effects on cancer risk in.

"Our conclusion, made possible a new paradigm is that we see a double effect," said Ragaz. "In terms of research, we have the mechanisms or biology that distinguish exogenous estrogens and has carcinogenic effects of endogenous estrogens to identify."

The study was described as "provocative" by Dr. Judy Garber, professor of medicine at the Dana-Farber Cancer Institute. But he said the idea called for further study and that current guidelines for hormone therapy in women should not change.