How Hormones Fit Into Breast Cancer Treatment
There is a common, and completely understandable, misconception out there that women with breast cancer are not supposed to undergo hormone therapy. But hormone therapy is different than hormone REPLACEMENT therapy (HRT). Hormone replacement therapy has been used for years to treat symptoms of menopause by increasing the level of certain hormones in your body, hormones whose level is dropping as your body slows down with age. Hormone replacement therapy is NOT recommended for breast cancer survivors; and healthy women are cautioned about its use, since it’s been shown to raise the risk of breast cancer.
Hormone therapy, on the other hand, involves the use of drugs to block the production of hormones in your body, or to block the hormones’ ability to attach themselves to your cells. Certain types of breast cancer rely on hormones to grow. Without the necessary hormones, cancer cells die, and the spread of the disease is stopped.
What are hormones again?
We hear about hormones (often “raging hormones”) all our lives, but what are they, exactly? As I've mentioned elsewhere: "Think of hormones as part of your body's communication system. Hormones are chemicals; they're manufactured in one part of your body, then travel to another part to direct and control certain processes."
Secreted by your glands (including thyroid, adrenal, et. al.), hormones are involved in almost every biological process, including reproduction, metabolism, growth, and disease protection. Basically, we’d be nowhere without hormones; they keep us alive and functioning. When they’re all in balance, we do fine; when they get out of whack (as they do during menopause), we feel it. Hot flashes, weight gain, sleeplessness, and nasty mood swings are all signs that our female sex hormone levels are dropping.
Female sex hormones: Estrogen and progesterone
Estrogen and progesterone are the main female sex hormones. They’re called that because they’re present in much greater quantities in females than in males; conversely, testosterone, a male sex hormone, is present in much greater quantities in males than females (although all of us, men and women alike, have at least some of each).
Estrogen plays a huge role in a number of biological processes. It impacts our ability to bear children as well as our weight (by controlling the speed of our metabolism, which is why we gain weight after menopause). It accelerates our growth during adolescence. It helps our circulation, and the elasticity of our skin (which is one reason why, as we grow older and estrogen production slows, we become increasingly wrinkled). It increases our HDL, and decreases our LDL, both of which help our cholesterol level. It even helps us breathe, by keeping the cells in our lungs elastic.
Progesterone is mainly concerned with reproduction. It regulates our periods, and has a major role in pregnancy, from conception to delivery. Progesterone also helps regulate estrogen; too much estrogen is just as harmful as not enough. (Some wags refer to estrogen as the wild teenager, and progesterone as the calm adult.) And it keeps us flexible (ligaments, joints, skin); helps our blood clot; makes sure our nerves work properly; and pitches in with a number of other body functions.
Many of us probably first heard about estrogen and progesterone in relation to birth control pills, which work by pumping synthetic estrogen and synthetic progesterone into your body on a set schedule. Estrogen prevents you from ovulating; no egg, no pregnancy. And progesterone is the backup, making it difficult for sperm and eggs to move, and for a fertilized egg to be implanted in the uterus.
Unfortunately, many of us also heard about estrogen and progesterone when our oncologist explained what type of breast cancer we’d been diagnosed with. About 70 percent of women with breast cancer have a type that grows with the help of estrogen and/or progesterone. Which is actually good news: there are drugs that are known to reduce the recurrence risk of hormone receptor-positive breast cancers. When you take any of these drugs – including tamoxifen, Evista, Arimidex, Femara, Aromasin, Zoladex, and Faslodex – you’re said to be undergoing hormone therapy.
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Breast cancer survivor and award-winning author PJ Hamel, a long-time contributor to the HealthCentral community, counsels women with breast cancer through the volunteer program at her local hospital. She founded and manages a large and active online survivor support network.
Updated on: May 13, 2016