- About 15-20 percent of people with breast cancer have triple negative breast cancer (TNBC).
- TNBC is often more aggressive than other types of cancers. That can make treatment more difficult.
- Hormone therapy isn’t usually an effective treatment for TNBC. Instead, treatment often involves chemotherapy, radiation, and surgery.
If you’ve been diagnosed with triple negative breast cancer (TNBC), you may wonder how your diagnosis will impact your life. Some questions you may have are:
- What is triple negative breast cancer?
- Is it treatable?
- What will treatment be like?
- What’s my long-term outlook?
The answer to those and other questions you have will depend on a lot of factors, such as the stage of your cancer and how well you respond to treatment. Keep reading to learn more about TNBC and your outlook.
The outlook for breast cancer is often described in terms of five-year survival rates. This survival rate represents the percentage of people who are still alive a minimum of five years after their diagnosis. Five-year survival rates tend to be lower for triple negative breast cancer (TNBC) than for other forms of breast cancer.
A 2007 study of more than 50,000 women with all stages of breast cancer found that 77 percent of women with TNBC survived at least 5 years. Ninety-three percent of women with other forms of breast cancer were found to survive at least five years. A 2009 study, however, found that the five-year survival rate for women with TNBC was similar to the survival rates for women with other cancers of similar stages. The 2009 study only included 296 women, so the study size was a lot smaller than the 2007 study group.
A separate study released in 2007 found that after 5 years of their diagnosis, women with TNBC no longer had a higher risk of death.
These survival rates shouldn’t be used to predict your outlook. Your doctor will be able to give you a more precise outlook based on the stage of your TNBC, your age, and your overall health. How well you respond to treatment will also determine your outlook.
If you’ve been diagnosed with breast cancer, one of the first things your doctor will do is determine whether the cancer cells are hormone receptive. Knowing if your cancer responds to certain hormones will help direct your treatment, and it can offer insight about your outlook.
Hormone receptors tell your cells how to behave. Some cancer cells have receptors for the hormones estrogen and progesterone, as well as an overexpression of the human epidermal growth factor receptor 2 (HER2) gene. If HER2 genes are overexpressed, the cells make too much of the protein HER2.
If your cells have hormone receptors, the hormones they receive will actually support the growth of your cancer cells. Not all breast cancer cells have these receptors and not all cancers overexpress the gene HER2. If your cancer isn’t receptive to these hormones and doesn’t have an increased amount of HER2, it’s called triple negative breast cancer (TNBC). TNBC represents 15-20 percent of all breast cancers.
Hormone therapy stops hormones from causing cancer growth. Because TNBC cells lack estrogen, progesterone, and their HER2 genes aren't overexpressed, the cells don’t respond well to hormone therapy or medications that block HER2 receptors. Instead of hormone therapy, treating TNBC often involves chemotherapy, radiation, and surgery.
Like other types of breast cancer, TNBC can often be treated successfully if it’s caught early. But in general, survival rates tend to be lower with TNBC compared to other forms of breast cancer. TNBC is also more likely than some other types of breast cancer to return after it’s been treated, especially in the first few years after treatment.
The stages of breast cancer are based on the size and location of the tumor, as well as whether the cancer has spread beyond the part of the breast in which it originated. To stage cancer, doctors use a scale of Stage 0 to Stage 4.
Stage 0 breast cancers are isolated in one part of the breast, such as duct or lobule, and show no sign of spreading into other tissue. Stage 1 breast cancer also often means that the cancer hasn’t spread outside of the breast. Stage 1 is typically localized, although further local spread may cause the cancer to move into stage 2.
In stage 3, the cancer has invaded the body’s lymph system. Stage 4 cancer is the most serious. Stage 4 cancer has spread beyond the breast and nearby lymph nodes, and into other organs and tissue of the body.
In addition to stages, breast cancers are given grades based on the size, shape, and activity of the cells in the tumor. A higher-grade cancer means a greater percentage of cells look and act unhealthy, or they no longer resemble normal, healthy cells. On a scale of one to three, with the three being the most serious condition, TNBC is often labeled Grade 3.
Even though TNBC doesn’t usually respond to treatment with hormone therapy, new medications called poly ADP-ribose polymerase (PARP) inhibitors are offering researchers hope. Finding a better treatment for TNBC is a major focus of breast cancer research.
In fact, research has found that there are six different subtypes of TNBC. Each one has its own abnormalities, but drugs geared toward those unique abnormalities are helping people with TNBC. Even though TNBC can be an especially aggressive type of breast cancer, your doctor may or may not recommend aggressive treatment. There is no standard recommendation for treating TNBC.
It’s also important to remember that no one, not even your doctor, can forecast exactly how your breast cancer will progress or respond to treatment. Survival rates are based on statistics, but everybody has an individual experience with the disease that cannot be predicted.
You asked, we answered
- I lost a family member to TNBC. Will I have a similar outlook? Is survival rate tied to genetics?
Survival rate of triple negative breast cancer is not tied to genetics. The BRCA1 and BRCA2 genetic mutations are the only breast cancer genes that scientists have linked to breast cancer. This means that if your family member has either of these mutations, you are 60-80 percent more likely to develop breast or ovarian cancer in your lifetime. If your family member has TNBC but does not carry the BRCA mutations, this does not suggest that you will have a similar outlook. However, there is an association between the BRCA1 mutation and TNBC. Among BRCA1 mutation carriers, at least one-third have triple negative breast cancers. If your family member has TNBC and was also a carrier of BRCA1 mutation, you should be tested for the BRCA genetic mutation to see if you are also a carrier to help you determine your prevention and treatment plans.- Helen Chen, MPH
- Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.