Understanding mBC

HR+, HER2- Metastatic Breast Cancer

Understanding HR+, HER2- Metastatic Breast Cancer

About Metastatic Breast Cancer

There are multiple stages of breast cancer, ranging from 0–4. When breast cancer progresses to stage 3 or 4, it becomes advanced breast cancer. In stage 3 breast cancer, the cancer has not yet spread to distant sites throughout the body, but it has spread beyond the breast and into nearby lymph nodes and muscles.


Stage 4 breast cancer (also referred to as advanced breast cancer or metastatic breast cancer) occurs when cancer that began in the breast has spread to other parts of the body. It’s important to note that regardless of where breast cancer is found in the body, it’s still breast cancer, and should not be considered as any other type of cancer. Breast cancer can metastasize in any part of the body, but it most commonly spreads to the bones, lungs, liver, or the brain.


While there is no cure for metastatic breast cancer, there are medicines available that can help slow the growth and spread of breast cancer tumors for both younger and older women. And some clinical trial data is showing that women are also living longer with metastatic breast cancer. Although a metastatic breast cancer diagnosis means that treatment will now be a part of your daily life, you do have options when it comes to managing your condition.

Facts About Metastatic Breast Cancer:

For premenopausal women:

icon-less-than-50It is estimated that as of January 2017, more than 20,000 women with mBC in the United States were younger than 50. 

Premenopausal Frequency IconThe frequency of metastatic breast cancer in women under 40 years old has increased over the last 30 years. 

icon-dotdropsNearly 80% of young women diagnosed with breast cancer find abnormal changes in their breast themselves.


For postmenopausal women:

icon-exclamationMetastatic breast cancer can occur 5, 10, or even 15 years after an early-stage diagnosis.


icon-bloodcellcounts-orange-bg61 is the average age women are diagnosed with de novo metastatic breast cancer.


icon-dotdrops84% of metastatic breast cancer deaths occur in women over the age of 50.

Types of Metastatic Breast Cancer

There’s more than one type of metastatic breast cancer. Each type is determined by whether or not certain proteins are found on or in cancer cells. These proteins include hormone receptors (HRs) and human epidermal growth factor receptor 2 (HER2). A plus sign means that your cancer has the protein, while a minus sign means that it has either a small amount of the protein or none at all.

Some Subtypes Are More Common Than Others

Illustration showing that HR+, HER2- (hormone receptor-positive, human epidermal growth factor receptor 2-negative) is the most common type of breast cancer.

HR+, HER2- (hormone receptor-positive, human epidermal growth factor receptor 2-negative) is the most common type of breast cancer, affecting approximately 73% of all people with metastatic breast cancer. HR+ breast cancer can also be referred to as ER+ (estrogen receptor-positive) or PR+ (progesterone receptor-positive). This means that the breast cancer is fueled by the hormone estrogen or progesterone.


Knowing your type is very important, and will help your doctor determine the treatment approach that’s right for you.