What is HER2-positive breast cancer?
Breast cancer is not a single disease. It’s actually a group of diseases. When diagnosing breast cancer, one of the first steps is identifying what type you have. This provides key information about how the cancer may behave.
When you have a breast biopsy, the tissue is tested for hormone receptors (HR). It’s also tested for something called human epidermal growth factor receptor 2 (HER2). Each can be involved in the development of breast cancer.
HER2 is a gene that creates HER2 proteins, or receptors. These receptors help control growth and repair of breast cells. An overexpression of HER2 protein causes out-of-control reproduction of breast cells.
HER2-positive breast cancers tend to be more aggressive than HER2-negative breast cancers. Along with tumor grade and cancer stage, HR and HER2 status helps determine your treatment options.
What are the survival rates?
At this time, there has been no specific research on survival rates for HER2-positive breast cancer alone. Current studies on breast cancer survival rates apply to all types.
When considering your outlook, your doctor must analyze many factors. Among them are:
Stage at diagnosis:
The outlook is better when breast cancer hasn’t spread outside the breast or has spread only regionally at the start of treatment. Metastatic breast cancer, which is cancer that has spread to distant sites, is harder to treat.
Size and grade of primary tumor:
This indicates how aggressive it is.
Lymph node involvement:
Cancer can spread from the lymph nodes to distant organs and tissues.
HR and HER2 status:
Targeted therapies can be used for HR-positive and HER2-positive breast cancers.
Other health issues may complicate treatment.
Response to therapy:
It’s hard to predict if a particular therapy will be effective or produce intolerable side effects.
Younger women and those over the age of 60 tend to have a worse outlook than middle-aged women, with the exception of those with stage 3 breast cancer.
What is the prevalence of HER2-positive breast cancer?
Approximately 12 percent of women in the United States will develop invasive breast cancer at some point. Anyone, even men, can develop HER2-positive breast cancer. But it’s more likely to affect younger women. HER2-positive represents about 20 percent of all breast cancers.
Can HER2-positive breast cancer recur?
HER2-positive breast cancer is more aggressive and more likely to recur than HER2-negative breast cancer. Recurrence can happen anytime. But it usually takes place within five years of treatment.
The good news is that recurrence is less likely today than ever before. This is largely due to the latest targeted treatments. In fact, most people treated for early stage HER2-positive breast cancer don’t relapse.
If your breast cancer is HR-positive, hormonal therapy may help reduce the risk of recurrence.
HR status and HER2 status can change. If breast cancer recurs, the new tumor must be tested so treatment can be reevaluated.
What treatments are available?
Your treatment plan will probably include a combination of therapies such as:
- targeted treatments
The size, location, and number of tumors help determine the need for breast-conserving surgery or mastectomy, and whether to remove the lymph nodes.
Radiation therapy can target any cancer cells that may remain after surgery. It can also be used to shrink tumors.
Chemotherapy is a systemic treatment. Powerful drugs can seek out and destroy cancer cells anywhere in the body. HER2-positive breast cancer generally responds well to chemotherapy.
HER2-positive breast cancer can also be HR-positive. If so, hormone treatments may be an option.
What is the outlook?
Once treatment for nonmetastatic breast cancer ends, you’ll still need periodic testing for signs of recurrence. Most side effects of treatment will improve over time, but some may be permanent.
Metastatic breast cancer is not considered curable. Treatment can continue as long as it’s working. If a particular treatment stops working, you can switch to another.
According to estimations, more than 3.1 million women in the United States have a history of breast cancer.
The outlook for HER2-positive breast cancer varies from person to person. Advancements in targeted therapies continue to improve the outlook for both early stage and metastatic disease.