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More bad news about hormones and breast cancer. Last summer, a women's health initiative study linked combination hormone therapy to an increased risk of heart attack, stroke and cancer.
Now researchers have taken a closer look and found more bad news.
Valerie Marcon, 63, is part of the women's health initiative study. She was in the treatment group taking prempro, a combination of estrogen and progestin, until that part of the study ended abruptly due to safety concerns.
Valerie: "I never worried about the medication being harmful."
But now there's more data showing that estrogen and progestin in combination can be harmful when it comes to breast cancer. That's according to a new study in the Journal of the American Medical Association.
Rowan Chlebowski, M.D., Ph.D./ WHI Researcher: "Estrogen and progestin may stimulate breast cancer growth and hinder breast cancer diagnosis."
Researchers analyzed mammography data from the WHI study which tracked more than 16,000 post-menopausal women over five years. Half were treated with prempro, the others a placebo or dummy pill.
Dr. Rowan Chlebowski: "Estrogen and progestin increased breast cancers by about 24 percent, and the cancers were found at a more advanced stage."
The tumors were larger and more likely to have positive lymph nodes, two factors that affect survival.
Their findings strongly suggest that breast cancers linked to hormones are not the good ones, as we once thought, and they occur earlier than expected. And that's not all.
About one in 25 women who took estrogen and progestin for one year wuld have an otherwise avoidable mommogram requiring additional medical intervention.
Nine percent of women taking estrogen-progestin had abnormal mammograms after just one year, compared to about five percent taking the placebo. That means greater anxiety and further costly workups.
Valerie Marcon: "I did have to have mammograms taken over again, and I guess that might be because of the density, or they couldn't get a reading."
So far Valerie's mammograms have not shown breast cancer. But now she and all women need to consider the risks of estrogen-progestin in treating the symptoms of menopause.
Combination therapy can make breast tissue more dense, so that finding small tumors on a mammogram is more difficult.
The concern is that by the time the cancer is diagnosed it's at a more advanced stage, which makes treatment and survival more difficult.
If you're taking hormones for symptoms, doctors now recommend using the lowest dose possible for as short a time as possible.