What Is Hormone-Positive Breast Cancer?

Hormone-receptor-positive breast cancer (HR+) is the most common subtype of breast cancer, affecting roughly 65 to 75 percent of breast cancer patients. It is one of several subtypes of breast cancer determined by the presence or absence of estrogen and/or progesterone hormone receptors. When patients are diagnosed with HR+ breast cancer, it suggests their cancer cells may be stimulated by the hormone estrogen.

How is HR+ breast cancer diagnosed?

The hormone-receptor status of the breast cancer cells is typically determined through a biopsy. The breast tissue sample is sent to a pathologist for analysis, where tests can determine if hormone receptors are present on the cancer cell.

How is HR+ breast cancer treated?

While the treatment plan is tailored to each patient, most approaches include hormonal therapies, also called endocrine therapies, that either reduce the body’s estrogen production or block hormonal signaling. The medications tamoxifen or aromatase inhibitors are often used to block the activity of estrogen in HR+ breast cancer patients. If a woman is premenopausal, turning off the ovaries can be another strategy to reduce estrogen in the body. If a cancer cell does not have hormone receptors, then the hormonal therapies are not included as part of the treatment plan. Today, doctors at Dana-Farber’s Susan F. Smith Center for Women’s Cancers are testing additional medications to enhance the effectiveness of hormonal treatments.