Does estrogen-only hormone replacement therapy decrease breast cancer risk?

April 2012

Nationally recognized endocrinologist Dr. Marina Johnson recently talked about the question: “Does estrogen-only hormone replacement therapy decrease breast cancer risk?”

Dr. Johnson, a pharmacist and UCLA/USC-trained physician, is board-certified in Endocrinology and Internal Medicine. Her book “Outliving Your Ovaries: An Endocrinologist Weighs The Risks And Rewards Of Treating Menopause With Hormone Replacement Therapy” is supported by 450 journal articles and 30 years of clinical experience.

A Synergy Note: At Synergy, hormone therapy doctors do not provide care through synthetic hormones. We only use bioidentical hormones, which is what more and more doctors are recommending for hot flashes, insomnia, anxiety, depression, sexual dysfunction, mental confusion, and weight gain. We agree with Dr. Johnson’s findings, which reinforce the health care we have been providing women for years in Chesapeake, Virginia Beach, Norfolk, Portsmouth, Suffolk, Williamsburg, Hampton Roads, Eastern Shore, Richmond, Virginia, North Carolina.

Here are Dr. Johnson’s thoughts on synthetic and natural/bioidentical hormones:

For years menopausal women heard that estrogen increases breast cancer risk. A March 2012 study in Lancet Oncology analyzing data from the Women’s Health Initiative (WHI) reported that menopausal women taking estrogen only have a lower risk of breast cancer while women who take a combination pill (Prempro) of estrogen-progestin have an increased risk.

At first glance this may seem contradictory since estrogen has been traditionally associated with increased breast cancer. It’s important for women to know that estrogen does not cause NEW cancer cells to grow. Most invasive breast cancers come from abnormal premalignant cells that take decades to grow. Estrogen can promote growth of these premalignant cells so they become detectable on clinical exam or mammogram.

When breast tissue is deprived of estrogen at menopause for 5 years or longer, premalignant cells shrink. This was the case in the WHI women who had been menopausal on NO Hormone Replacement Therapy (HRT) for 8 years or longer. When estrogen is initiated within 3 years of menopause there’s an increased risk of breast cancer. However, a French E3N cohort study showed that if you chose natural estradiol and progesterone over synthetic estrogens and progestins, there’s no increased breast cancer risk, even if you start it within 3 years.

You don’t need to delay starting HRT if you choose natural estradiol and progesterone over synthetic estrogens and progestins. Don’t endure symptoms like hot flashes, insomnia, anxiety, depression, sexual dysfunction, mental confusion, and weight gain. Start HRT within 10 years of menopause for the most protection against Heart Disease, Alzheimer’s and Osteoporosis.