Does Hormone Replacement Therapy Cause Cancer?

If hot flashes and night sweats are your new normal, they don’t have to be. Menopause can be difficult and affect your quality of life in many ways. For some people, hormone replacement therapy (HRT) can help you feel like you again — but are there any health risks involved?

Ob/Gyn and menopause specialist Stephen Livingston, MD, explains how HRT might improve your menopause experience and what current research says about its possible cancer risks.

How does HRT help menopause symptoms?

Women and people assigned female at birth (AFAB) have two main sex hormones — estrogen and progesterone. This duo makes ovulation and menstruation possible.

Your hormone levels start to change in perimenopause, about eight to 10 years before menopause. When your estrogen starts to drop, it throws off the balance of estrogen and progesterone in your body. That’s when you may start to experience symptoms, while still having menstrual cycles. Then, when you reach menopause (typically around age 52), your body makes such a small amount of estrogen that your ovaries stop releasing eggs — and you stop having periods entirely.

For some people, hormone fluctuations can feel like a rollercoaster. Menopause symptoms can include:

• Frequent urges to pee.
• Hot flashes.
• Insomnia.
• Mood swings.
• Night sweats.
• Pain during sex.
• Vaginal dryness.

“The goal of HRT is to replace estrogen lost in menopause,” Dr. Livingston explains. “While the goal isn’t necessarily to eliminate 100% of your symptoms, HRT can significantly help most people with the majority of their menopause symptoms.”

There are two main types of hormone replacement therapy. The type you use depends on whether you have a uterus:

1. If you have a uterus: Your provider will prescribe estrogen progesterone/progestin hormone therapy (EPT). This HRT contains both estrogen and progesterone or progestin (a manmade form of progesterone). It’s also called combination therapy.
2. If you no longer have a uterus: Your provider will prescribe therapy that contains only estrogen. It usually comes in a pill or patch but is also available as a cream, vaginal ring, gel or spray.

Can hormone replacement therapy cause cancer?

Any risk is thought to be minimal. So, why is this such a hot topic? The debate about hormone replacement therapy goes back to the Women’s Health Initiative, a large study released in the early 2000s.

“That seems to be where the identification of a risk first occurred,” Dr. Livingston says. “Since then, though, additional studies and analysis have shed more light on the real risks of HRT. Not only is the cancer risk associated with HRT minimal, but HRT can even help reduce the risk of certain cancers in some people.”

Dr. Livingston explains the latest research on HRT and the risk of certain types of cancer.

Breast cancer and HRT

“While there does appear to be a very small risk of breast cancer from taking estrogen and progesterone/progestin therapy, it’s about 1 in 1,000 cases,” he notes. While this slightly increased risk might sound worrisome, he says recent data suggests no increase in mortality, and this cancer is typically treatable.

There’s even some good news for women who’ve had a hysterectomy and are taking estrogen-only HRT. With this HRT regimen, the rate of breast cancer is actually less than for those not taking HRT.

The bottom line? “The risk is not zero, but the risk of developing breast cancer from HRT is very low,” Dr. Livingston says.

Colon cancer and HRT

No matter which type of HRT you’re on, recent studies show a nearly 40% reduction in cases of colon cancer in post-menopausal people who take hormone replacement therapy.

Ovarian cancer and HRT

“The jury is still out here,” Dr. Livingston says. “While some studies point to a minor increase in the risk of ovarian cancer with HRT, the evidence isn’t conclusive.”

There are also studies that suggest estrogen therapy might improve the survival of people who’ve already been diagnosed and treated for ovarian cancer.

“With ovarian cancer, overall I’d say that any pluses or minuses seem to balance out,” he adds.

Is HRT right for you?

If menopause symptoms are affecting your ability to enjoy life, HRT might be the answer you’ve been looking for.

“In our evolution as menopause practitioners since the Women’s Health Initiative, we have determined the safest types of HRT and the safest ways to administer them to you,” Dr. Livingston reassures.

But most importantly, HRT is about you.

“It’s not just about what the lab tests show us,” he continues. “We want to hear how you’re doing. When we prescribe hormone replacement therapy, our goal is to help you feel and function much like you did before menopause.”