Hormone Receptor Positive Breast Cancer
Hormone receptor positive breast cancer is the most common form of breast cancer, accounting for 70 to 80% of all cases. This type of cancer uses the body’s natural hormones, particularly estrogen and progesterone, to fuel its growth—but understanding this characteristic also opens the door to targeted treatments that can effectively block these hormones and improve outcomes.
Table of contents
- What is hormone receptor positive breast cancer?
- Types of hormone receptors
- How hormone receptor status is determined
- Treatment approaches
- Managing treatment side effects
- Lifestyle factors and prognosis
What is hormone receptor positive breast cancer?
Hormone receptor positive breast cancer means that the cancer cells have special proteins, called hormone receptors, on their surface that respond to hormones in the body. When the hormones estrogen and progesterone attach to these receptors, they send signals that cause the cancer cells to divide and the tumor to grow.[1][2]
Approximately 67% to 80% of breast cancers in women are hormone receptor positive, making it the most common type of breast cancer. In men with breast cancer, about 90% are estrogen receptor positive and approximately 80% are progesterone receptor positive.[2][3]
This type of breast cancer typically grows more slowly than hormone receptor negative cancers. The presence of hormone receptors is actually good news because it means the cancer can be treated with therapies that block the effects of hormones or reduce hormone levels in the body.[3]
Types of hormone receptors
Breast cancer cells can contain two main types of hormone receptors: estrogen receptors and progesterone receptors. These receptors receive messages from hormones circulating through the body and respond by telling the cells what to do.[1]
When breast cancer cells contain estrogen receptors, the cancer is called estrogen receptor positive or ER-positive. Most breast cancers are ER-positive. Estrogen is a hormone that plays an important role in the reproductive system. In premenopausal women, estrogen is produced mainly by the ovaries, but some other tissues including fat and skin also produce it in both premenopausal and postmenopausal women and in men.[1][2]
If breast cancer cells contain progesterone receptors, the cancer is called progesterone receptor positive or PR-positive. Progesterone is another hormone involved in the female reproductive system. Most PR-positive breast cancers are also ER-positive.[1][4]
A tumor can be positive for one or both hormone receptors. Some cancers are also triple-positive, meaning they are ER-positive, PR-positive, and also positive for another protein called HER2 (human epidermal growth factor receptor 2).[3]
How hormone receptor status is determined
Healthcare providers determine hormone receptor status through testing on tumor tissue samples. This testing is done on tissue removed during a biopsy (removal of tissue to be examined under a microscope) or after surgery to remove the cancer.[1][2]
The test typically uses a method called immunohistochemistry, which measures how many hormone receptors are present on the cancer cells. Results are usually reported as a percentage. Higher percentages mean the tumor is more responsive to hormones.[3]
All invasive breast cancers (cancers that have the potential to spread to other parts of the body) should be tested for both estrogen and progesterone receptors. The information from these tests is critical because it helps doctors determine the best treatment plan for each patient.[1][4]
It’s important to know that if breast cancer returns or spreads to other parts of the body, the hormone receptor status can change. For example, if the first tumor was treated with hormone therapies, a cancer that returns may become resistant to that therapy. In other cases, the tumor may undergo changes to gain or lose hormone receptor presence. That’s why doctors may recommend retesting the cancer’s characteristics if it comes back or progresses.[3]
Treatment approaches
Hormone receptor positive breast cancer can be effectively treated with hormone therapy, also called endocrine therapy or anti-estrogen therapy. This type of treatment works differently from hormone replacement therapy used for menopause symptoms. While hormone replacement therapy increases estrogen levels, hormone therapy for breast cancer blocks or lowers estrogen levels in the body.[2][11]
Hormone therapy may be used in several ways. It can be given before surgery to shrink a large tumor, making it easier to remove. After surgery, it helps reduce the risk of the cancer coming back. For advanced-stage breast cancer, hormone therapy can help stop the cancer from growing. It can even be used preventively in women who have a much higher than average risk of developing breast cancer.[11]
There are three main types of hormone therapy medications. Aromatase inhibitors stop the body from making estrogen by blocking an enzyme called aromatase. Selective estrogen receptor modulators (such as tamoxifen) block the action of estrogen on certain cells. Selective estrogen receptor downregulators also block the action of estrogen on cells.[11][12]
Another treatment approach involves blocking ovarian function. Because the ovaries are the main source of estrogen in premenopausal women, reducing ovarian function can lower estrogen levels. This can be done permanently through surgery to remove the ovaries or temporarily through medication.[2]
Doctors usually recommend that patients take hormone therapy for 5 to 10 years, depending on the risk of cancer recurrence. This type of treatment is remarkably effective. For localized, early-stage breast cancer, the five-year survival rate is now 99%.[17]
Hormone therapy is often used along with other treatments such as surgery, radiation therapy, chemotherapy, or targeted therapies. The specific combination depends on the individual characteristics of the cancer and the patient’s overall health.[1][13]
Managing treatment side effects
While hormone therapy is highly effective, it can cause side effects. Common side effects include hot flashes, bone and joint pain or stiffness, vaginal dryness, brain fogginess, and bone thinning in younger women. It’s important to note that not everyone experiences these side effects. Some people rarely have them, while others find they significantly affect quality of life.[17]
Many patients avoid taking hormone therapy for the full prescribed length of time because of side effects. However, there are several strategies that can help manage these symptoms and make it easier to continue treatment.[17]
For bone loss, medications like bisphosphonates can reduce the risk of osteoporosis. For hot flashes, certain medications normally used to treat anxiety or depression can also help manage flushing symptoms, though it’s important to discuss both benefits and risks with a doctor.[17]
Women experiencing sexual side effects can get relief with appropriate lubricants and, in some instances, topical estrogens. Recent data show no evidence that topical estrogens used by women with hormone receptor positive breast cancer increase the risk of breast cancer death, but the pros and cons should be reviewed with a healthcare provider.[17]
Lifestyle changes can significantly improve health without medications. Research shows that exercise is a key component for extending cancer survivorship and managing side effects. Exercise can range from vigorous aerobic activity to gentle yoga, tai chi, strength training, or walking. Doctors should supervise exercise plans based on the patient’s physical fitness at the start of treatment.[14][17]
Mindfulness practices including group therapy, behavioral therapy, education about managing psychological trauma, deep breathing, meditation, and yoga can alleviate anxiety, depression, fatigue, and other side effects. Acupuncture has also been shown to help with pain, hot flashes, joint pain, and nerve-related symptoms.[17]
It’s important to talk with healthcare providers about side effects. In many cases, medications, physical therapy, exercise, and complementary therapies can ease discomfort and help patients continue with their treatment.[14]
Lifestyle factors and prognosis
Several lifestyle factors can influence outcomes for people with breast cancer. Research suggests that making positive changes can reduce the risk of recurrence and improve overall health. Making these changes can also be psychologically beneficial, helping patients feel more in control after a cancer diagnosis.[16]
Maintaining a healthy weight is important. Women who gain weight during or after breast cancer treatment, or who are overweight or obese at the time of diagnosis, have been shown to have a poorer prognosis. Weight management through diet and exercise can help improve outcomes.[16]
Physical activity is consistently associated with better outcomes. Exercise can help manage treatment side effects, improve mental health, and may reduce the risk of cancer recurrence. The American Cancer Society recommends regular physical activity for cancer survivors.[16][17]
Diet also plays a role. Experts recommend eating a healthy diet that is high in fiber and low in saturated fats. High-fiber foods include whole grains, pulses like lentils and beans, vegetables, and fruits. Foods high in saturated fat, such as butter, fatty meats, and full-fat dairy products, should be limited.[18]
There is some evidence that fiber may reduce the risk of breast cancer recurrence, though more research is needed. Similarly, some evidence suggests that saturated fat may increase the risk of recurrence, but further research is needed to confirm this.[18]
Limiting alcohol consumption is recommended. The World Cancer Research Fund advises people who have had breast cancer to limit alcohol as part of reducing their risk of cancer coming back.[18]
Patients should discuss with their doctors before using herbal supplements, vitamins, energy drinks, protein powders, or other non-regulated health products, as some can interact with cancer treatment or cause other health problems.[17]
Family and friends provide important emotional support. Finding supportive communities, whether through groups, therapy, or education programs, can help with the psychological challenges of diagnosis and treatment.[14]
