- Women who have been through natural menopause have a higher risk of developing cancer because they are older, which is a risk factor for cancer.
- Combined hormone therapy to treat menopausal symptoms may increase a woman’s risk of cancer.
Menopause does not cause cancer, but the risk of developing cancer increases as a woman ages. Therefore, women who have been through natural menopause are more likely to develop cancer because they are older.
Menopause occurs when a woman’s ovaries stop releasing eggs. During natural menopause, a woman’s body makes less of the hormones estrogen and progesterone, causing irregular menstrual periods that eventually stop. It generally begins during a woman's mid-40s or early- to mid-50s. However, it may begin earlier if cancer treatment—such as surgery, chemotherapy, or hormone therapy—stops the ovaries from working; this is called premature menopause. Learn more about long-term side effects of cancer treatment.
The symptoms of menopause include hot flashes, night sweats, vaginal dryness, painful sexual intercourse, decreased sex drive, osteoporosis (thinning of the bones), bladder control difficulties, mood swings, and insomnia. Find out how to manage menopausal symptoms.
Menopause and cancer risk
A woman who experiences menopause after age 55 has an increased risk of ovarian, breast, and uterine cancers. The risk is greater if a woman also began menstruating before age 12. This is because a woman who menstruates longer than normal during her lifetime is exposed to more estrogen and has more ovulations. A longer exposure to estrogen increases a woman’s risk of uterine and breast cancers, and having more ovulations than normal increases a woman’s risk of ovarian cancer.
Menopausal hormone therapy and cancer risk
Combined hormone therapy (also called postmenopausal hormone therapy or hormone replacement therapy) may help relieve menopausal symptoms such as hot flashes and osteoporosis. It is a combination of estrogen and progestin (a form of progesterone made in a laboratory). However, the National Institutes of Health’s Women’s Health Initiative study found that women taking combined hormone therapy to manage menopausal symptoms have a higher risk of breast cancer, heart attack, stroke, and blood clots (although they did have a lower risk of colorectal cancer and bone fractures). Because of these risks, doctors typically do not recommend this treatment for women—particularly women who have a history of breast cancer or those who have a higher risk of breast cancer. Or, in some cases, it is given at a low dose for a short time.
In addition, research has shown that women who receive combined hormone therapy have a higher risk of dying from non-small cell lung cancer (NSCLC) if they develop the disease. However, woman in the study who were taking combined hormone therapy were not more likely to develop NSCLC than women who were not taking combined hormone therapy. The study also showed that the risk of dying from lung cancer is higher for women with NSCLC who smoke and take combined hormone therapy.
Hormone therapy with estrogen alone is a consideration only for women who have had their uterus surgically removed (a hysterectomy) because estrogen that is not balanced by progesterone can spur growth of the uterus lining, which increases the risk of uterine cancer.
The effects of combined hormone therapy on women are controversial, and the risks and benefits of the treatment are different for each woman. Research in this area is ongoing. If you are considering hormone therapy for menopausal symptoms, talk with your doctor about your symptoms, medical history, and options for relieving your symptoms, including the risks and benefits of those options.