Cancer Risk Terminates Hormone Therapy Study

Scandinavian scientists announced Tuesday that they have called off a study of the effects of hormone replacement therapy for women with a history of breast cancer because early results showed an unacceptably high risk of recurrence.

The researchers, led by Dr. Lars Holmberg of University Hospital in Uppsala, Sweden, had intended to monitor their patients for five years.

They said they called off the study Dec. 17 based on results from 345 women they had been monitoring for an average of two years. Half were given hormone replacement therapy and the other half received non-hormonal treatment for menopausal symptoms.

In the replacement therapy group, 26 women had a recurrence or developed a new case of breast cancer. That compared with seven women who took the other treatment. The findings were published Tuesday by the Lancet medical journal.

At the American Cancer Society, Dr. Harmon Eyre noted that doctors occasionally offer hormone replacement to breast cancer survivors with severe menopausal symptoms, because a handful of small, preliminary studies showed no risk.

“This study will no doubt change that,” Eyre said.

Unlike earlier studies, the Scandinavian trial did not find a significant difference in risk between types of hormone treatment.

Eighteen months ago, U.S. government scientists abruptly ended the nation’s biggest study of hormone replacement therapy using the combined hormones estrogen and progestin, saying long-term use significantly increases women’s risk of breast cancer, stroke and heart attack. That study involved older women who were well past menopause.

Last year, a British study concluded that women receiving hormone replacement therapy had a 22% higher risk of death from breast cancer than women who were not, and those who used estrogen and progestin together had a markedly higher risk than those who used estrogen alone.