Triple Positive Breast Cancer Prognosis

HER2-positive, ER-positive, and PR-positive

Triple-positive breast cancer has three features that influence its prognosis and set it apart from other subtypes of breast cancer. It grows in response to two hormones and makes a lot of a protein called human epidermal growth factor receptor 2 (HER2).

While these features mean cancer grows fast, it also means that it has many treatment options. It responds to both hormone treatments and targeted treatments against HER2. However, new research suggests that it may not respond as well to these drugs as other breast cancers with HER2.

While triple-positive breast cancer can be aggressive, the outlook for this type of cancer is better than triple-negative breast cancer and cancers with HER2 but without hormone receptors. Triple-negative breast cancers have the lowest survival rate of all breast cancer subtypes.

This article explains the general outlook for triple-positive breast cancers and what you can do to improve your prognosis and quality of life. The article also covers how many people survive triple-positive breast cancer and how likely it is to return.

A Black adult with dark chin-length hair wearing a blue hospital gown standing in a mammogram exam room.

Isaac Lane Koval/Corbis/VCG / Getty Images

What Is Triple Positive Breast Cancer?

Triple-positive is one of the many subtypes of breast cancer. The subtypes are defined by their molecular characteristics—the proteins they make and the genes they express. The two main proteins that define a subtype are the hormone receptors and the HER2 protein. 

Hormone Receptors

The cell’s hormone receptors are proteins on its surface that see signals from hormones and make cancer cells grow. The most critical hormones in breast cancers are estrogen and progesterone. Cancers can be hormone receptor-positive (HR-positive), which means the cancer cells have estrogen receptors (ER), progesterone receptors (PR), or both.

Cancer cells with hormone receptors are typically slow growing and respond well to treatments that block the hormone signals.

HER2

HER2 is a growth-promoting protein expressed by some breast cancers. About 15% to 25% of breast cancers make a lot of HER2.

HER2-positive breast cancers grow and spread quickly, but there are treatments targeted at them. These treatments give people with HER2-positive cancers more options.

Subtypes of Breast Cancer

According to the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Result (SEER) cancer database, the four molecular subtypes of breast cancer are:

  • HR-positive/HER2-negative (sometimes called Luminal A) is the most common subtype, accounting for 68% of cases.
  • HR-positive/HER2-positive (sometimes called Luminal B) is tied for the second most common, accounting for 10% of cases.
  • HR-negative/HER2-negative (sometimes called basal-like or triple-negative) is tied for the second most common, accounting for 10% of cases.
  • HR-negative/HER2-positive (called HER2-enriched) accounts for about 4% of breast cancers. 

In approximately 7% percent of cases in the NCI database, the subtype is unknown.

Triple-positive breast cancers fall under the HR-positive/HER2-positive subtype, a heterogeneous group of cancers. HR-positive/HER2-positive breast cancer includes cancers that are:

  • ER or PR positive (though they most commonly have low ER levels and do not have PR)
  • Have high levels of HER2 or the protein Ki-67 (both of which indicate that the tumor is actively growing)

HR-positive/HER2-positive cancers are typically given a higher score that indicates how abnormal cancer cells look in the lab (grade) than HR-positive/HER2-negative cancers. They also have worse outcomes.

Triple-positive breast cancer falls under the HR-positive/HER2-positive category because it's HR-positive and HER2-positive. A small portion of these cancers and triple-positive cancers have some unique features because they have both ER and PR.

Survival Rates for Triple-Positive Breast Cancer

Triple-positive and other HR-positive/HER2-positive cancers are generally more aggressive and have a slightly less positive outlook than other breast cancers. However, the outlook for triple-positive breast cancer is better than it is for triple-negative breast cancer. 

There is not a lot of specific data on triple-positive breast cancer prognosis. In a small study of people with triple-positive breast cancers, 5.9% died within 33 months of diagnosis.

Generally, HR-positive cancers have a better prognosis because they respond to hormone therapies. They also typically grow slower than HR-negative cancers. While they may recur, this normally does not happen for many years after treatment.

HER2-positive cancers generally have a worse prognosis than HER2-negative cancers. However, this might change with the development of targeted therapies against HER2.

According to NCI data, the five-year relative survival rate for HR-positive/HER2-positive female breast cancer is 90.7%.

NCI data is also broken down by how advanced the disease is when diagnosed:

  • Cancer that is still only in the breast tissue is localized.
  • Cancer that has spread to other tissues in the chest, including lymph nodes, is regional.
  • Cancer that has spread to organs in other body parts is distant.
Breast Cancer Occurance and Survival Rates by Subtype
Subtype Occurrence Survival rate (overall) Survival rates (localized/regional/distant)
HR-positive/HER2-negative 68% 94.4% 100% / 90.1% / 31.9%
HR-positive/HER2-positive 10% 90.7% 98.8% / 89.3% / 46.0%
HR-negative/HER2-positive "HER2 enriched" 4% 84.8% 97.3% / 82.8% / 38.8%
HR-negative/HER2-negative "Triple-negative" 10% 77.1% 91.3% / 65.8% / 12.0%
Data from the National Cancer Institute's SEER database on the occurrence and survival rates for different subtypes of breast cancer based on hormone receptor and HER2 status.

HR-positive/HER2-negative breast cancers have the best survival statistics of all breast cancer subtypes. HR-positive/HER2-positive, which includes triple-positive breast cancers, have the second-best survival pattern. HR-negative/HER2-positive cancers have worse survival rates, and HR-negative/HER2-negative (triple-negative) have the worst. 

A 2018 study that specifically looked at triple-positive breast cancer in Korea found a survival rate between that of HR-positive/HER2-negative and HER2-enriched subtypes, similar to the rates from the NCI database.

Recurrence

Triple-positive breast cancers can come back, but they’re usually slower to recur than other types of breast cancer. They often come back more than five years after initial treatment, which may give people a false sense of security. On the other hand, HER2-positive/ER-negative cancers typically come back before five years.

For example, in the 2018 Korean breast cancer study, people with an average follow-up of a bit over six years had the following rates of recurrence:

  • 6.5% of triple-positive breast cancers recurred
  • 4.0% of HR-positive/HER2-negative cancers recurred
  • 10.7% of the HER2-enriched cancers recurred

Treatment for Triple-Positive Breast Cancer

The primary treatment for breast cancers of all kinds is surgery to either remove the cancerous lump (breast-conserving surgery) or the entire breast (mastectomy). Surgery can also involve removing and testing lymph nodes in the chest for cancer.

In addition to surgery, breast cancer treatment can also include:

  • Chemotherapy drugs that kill fast-growing cells throughout the body
  • Radiation therapy with high energy waves that kill cells (given as a beam or implanted seed)
  • HER2-targeted therapy drugs that specifically impair growth and division in cells that express a lot of HER2
  • Hormone therapy drugs that block or stop hormones from helping cancer grow

For triple-negative breast cancers, chemotherapy might be needed before or after surgery if your cancer is advanced (stage 2 or stage 3) or has genetic signals that suggest it may come back after treatment.

In addition, many breast cancers are treated with radiation after surgery to make sure all of the cancer is killed. This is usually done when a person opted for breast-conserving surgery or cancer was found in four or more lymph nodes.

In addition to these typical treatments for breast cancers, triple-positive breast cancers can also benefit from HER2-targeted and hormone therapies.

HER2 therapy targets cells that express high levels of the HER2 protein. Therapies that specifically target HER2 include monoclonal antibodies, antibody-drug conjugates, and kinase inhibitors.

Monoclonal antibodies are manufactured versions of immune system proteins called antibodies that bind to cellular proteins (in this case, HER2). Examples include:

  • Herceptin (trastuzumab)
  • Perjeta (pertuzumab)
  • Margenza (margetuximab) 

Antibody-drug conjugates are anti-cancer drugs glued to antibodies targeting HER2. They find the cancer cells using HER2, block the HER2 signal, and drop off deadly drugs. Examples include:

  • Kadcycla (trastuzumab emtansine)
  • Enhertu (fam-trastuzumab-deruxtecan-nxki)

Kinase inhibitors block the signals that the HER2 protein uses to tell the cells to grow. Examples include:

  • Tykerb (lapatinib) 
  • Nerlynx (neratinib) 
  • Tukysa (tucatinib)

In addition to HER2 therapies, triple-positive cancers may respond to hormone therapy. These drugs stop or block hormones from reaching the cancer cells. They may stop your body from making hormones or binding to the cancer cells' receptors. These halt the growth signals that the hormones are sending to cancer.

These drugs are typically taken for many years after other treatments have stopped because they help reduce the chance that cancer will return. Hormone therapy, also called endocrine therapy, for breast cancer may include selective estrogen receptor modulators (SERMs) that block estrogen signals in the breast tissue but act like estrogen in other tissues. SERMs include:

Selective estrogen receptor degrader (SERD) can turn down the estrogen signals throughout the body. Examples include:

  • Faslodex (fulvestrant)

Aromatase inhibitors turn down the body's production of estrogen. They are only for post-menopausal people. Examples include:

One complicating factor is recent evidence that triple-positive breast cancers may not react as well to HER2 and hormone therapies as other cancers that are only HER2-positive or only HR-positive.

Targeting both pathways for treatment seems to cause "crosstalk" within the cancer cells, which appears to lower the efficacy of both types of treatment. According to an Italian study of people with triple-positive breast cancer, this is most evident in triple-positive cancers that express high levels of both hormone receptors.

In a 2018 Korean study, the HER2-targeted drug trastuzumab did not improve overall survival among people with triple-positive breast cancer. However, it did increase survival for people with the HER2-enriched subtype.

There is still debate about how effective HER2 or hormone therapies are against triple-positive breast cancers. They may prolong survival, even if they are less effective. Other HER2 treatments may work better than trastuzumab. 

How to Improve Outlook

Breast cancer is most treatable—and curable—when it's caught early. The best way to improve your breast cancer prognosis is to get screening mammograms regularly when your healthcare providers suggest and follow up with them about any concerning symptoms.

The less advanced your cancer is when it’s found, the more accessible treatment is and the better your outlook—no matter the subtype.

If you’ve already been diagnosed with triple-positive breast cancer, consider these steps to improve your outlook:

  • Talk to your healthcare provider about what treatments will work for you. 
  • Find a specialist oncologist who works with triple-positive breast cancers.
  • Consider clinical trials of new therapies.
  • Know that no two breast cancers are the same. 
  • Connect with other people with breast cancer through support groups.
  • Keep a positive outlook and take care of your mental health.
  • Follow a healthy lifestyle—for example, eat a nutritious diet and stay active. 

Summary

Triple-positive breast cancers are a newly recognized and unique subset of hormone receptor-positive and HER2-positive breast cancers. They make up a small portion of all breast cancers.

While there are many treatment options, this subtype of cancer's unique molecular characteristics may make some treatments less effective than they would be for other breast cancers.

Generally, the survival rate for triple-positive breast cancers is better than for triple-negative breast cancers but lower than it is for breast cancers that do not have high levels of HER2.

A Word From Verywell 

Any diagnosis of breast cancer is distressing. While triple-positive breast cancer can be aggressive, it will be comforting to know that it has many treatment options and an overall good outlook. 

Frequently Asked Questions

  • Which type of breast cancer is the most aggressive?

    Several factors influence a tumor's aggression, including its biological makeup, size, stage (how far it has spread), etc. Here are some key takeaways about the aggressiveness of different breast cancers:

    • HER2-positive breast cancers are more aggressive.
    • Inflammatory breast cancers are more aggressive.
    • Triple-negative breast cancers are harder to treat.
    • Breast cancer that has already spread to the lymph nodes (locally advanced) or other parts of the body (metastatic) before its discovered will need more aggressive treatment.
    • A rare breast cancer called angiosarcoma of the breast is more aggressive than other common breast cancers.
  • Does triple-positive breast cancer usually spread?

    Triple-positive breast cancer is a more aggressive subtype of cancer, as it has a lot of growth-promoting HER2 proteins. In a study of 85 people in the United States with triple-positive breast cancer, 58.9% had cancer in their lymph nodes when they were first diagnosed.

  • Can chemotherapy be used to treat triple-positive breast cancer?

    Chemotherapy is often used to treat triple-positive breast cancer, especially at stage 2 or 3. It can be used before surgery or after.

19 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Jennifer Welsh
Jennifer Welsh is a Connecticut-based science writer and editor with over ten years of experience under her belt. She’s previously worked and written for WIRED Science, The Scientist, Discover Magazine, LiveScience, and Business Insider.