Triple-negative breast cancer (TNBC) is a type of breast cancer. It tends to be more aggressive than other types of breast cancer, meaning it grows and spreads faster. About 15 to 20 percent of breast cancers are triple-negative.
Cancerous tumors are graded on a scale of 1 to 3. TNBC tumors are likely to be grade 3, which means the cancer cells bear little resemblance to normal, healthy breast cells. TNBC tumors also test negative for estrogen receptors (ER), progesterone receptors (PR), and a gene called human epidermal growth factor receptor 2 (HER2).
Because there are no receptors for ER, PR, or HER2, TNBC doesn’t respond to targeted therapies such as tamoxifen and trastuzumab (Herceptin). These are commonly used for other types of breast cancer.
Fortunately, TNBC can be effectively treated.
Your treatment plan for TNBC will likely include a combination of surgery, radiation, and chemotherapy.
In breast-conserving surgery, or a lumpectomy, the tumor and a small amount of surrounding tissue are removed.
In some cases, you may need a mastectomy instead of a lumpectomy. There are several types of mastectomy:
- Total or simple mastectomy, which is removal of the breast, nipple, areola, and most of the overlying skin.
- Modified radical mastectomy, which also includes removal of the lining over the chest muscles and axillary lymph nodes under the arm. Part of the chest wall is sometimes removed.
- Radical mastectomy, which is a rare procedure that also includes removal of the chest muscles.
If you plan on reconstruction, a skin-sparing or nipple-sparing mastectomy may be an option, but only if there’s no evidence of cancer near the skin or areola. In most cases, a mastectomy requires an overnight hospital stay. Recovery time is about six weeks. Breast reconstruction requires additional procedures.
After a mastectomy, surgical drains will be left in your chest to allow fluids to escape. They’ll be removed in a week or two. Side effects of a mastectomy can include:
- tenderness and swelling of the chest
- underarm pain or shoulder stiffness
- phantom breast pain and unusual sensations
Lymph node removal may increase your risk of swelling of the arm, known as lymphedema.
The type of surgery you have depends on a variety of factors, including:
- number, size, and location of tumors
- whether there is cancer in the skin or nipple area
- if there are other abnormalities of the breast
- whether or not you plan on breast reconstruction
If you’re not having reconstruction, you can be fitted for a prosthetic breast in about six weeks.
Radiation is used to kill any cancer cells that might have been left behind after surgery. Radiation beams will be targeted to the area where cancer was found. This may be especially important if cancer was found close to the chest wall or in your lymph nodes.
To help target the radiation beams, your chest will be marked with tiny tattoos. Because radiation can’t be repeated in the same location should cancer recur, the tattoos will help guide future treatment.
Radiation is usually given five days a week for five or six weeks. Great attention will be given to getting your body in the proper position. The treatment itself takes only a few minutes, during which you’ll have to remain perfectly still.
Side effects of radiation therapy may include:
- sunburn-like skin color and irritation
- dry, itchy skin
Chemotherapy drugs are a type of systemic treatment. This means they’re designed to destroy cancer cells, no matter where they’ve traveled in your body. The goal is to prevent breast cancer from spreading or metastasizing.
Chemotherapy can be used to shrink a tumor prior to surgery, or it can be given after surgery to kill wayward cancer cells.
There are a variety of chemotherapy drugs used to treat TNBC, including:
- AC: doxorubicin (Adriamycin) with cyclophosphamide
- FAC (or CAF): AC plus fluorouracil (5FU)
- FEC (or CEF or EC): epirubicin (Ellence) given in place of doxorubicin
- taxanes: paclitaxel and docetaxel (Taxotere) given with AC (ACT) or FEC (FEC-T)
These drugs are usually given intravenously in cycles of 1-3 weeks. The entire treatment may last 3-6 months or longer in some cases. Side effects of chemotherapy may include:
- nausea or vomiting
- loss of appetite and weight loss
- mouth sores
- changes to fingernails and toenails
- hair loss
Clinical trials are a way to test the effectiveness of potential new therapies for TNBC. By taking part in a clinical trial, you’re helping to advance research into treatment for TNBC.
Trials can offer access to treatments that aren’t yet approved for general use. You’ll be closely monitored, but there’s no guarantee that the treatment will work. Or you’ll receive standard (or routine) treatment so researchers can compare your results to patients taking the experimental (or investigational) treatment. Some studies use a combination of standard treatment and investigational treatment. In these studies, you can still benefit from standard treatment while also helping advance research into TNBC with new treatments.
There are some things you should consider before participating in a clinical trial:
- the proximity of treatment to where you live
- how often you’ll be required to see a doctor or have additional testing
- unknown side effects
- what will be covered by your health insurance and what your potential direct and indirect out-of-pocket expenses might be
To participate, you’ll have to meet certain qualifications regarding your diagnosis, treatments you’ve already received, and your overall health.
Your doctor can provide more information on clinical trials for which you might qualify. You can also visit the National Cancer Institute’s searchable database.
TNBC is more aggressive and sometimes harder to treat than some other types of breast cancer. Your outlook depends on a variety of factors, such as the number and size of tumors, grade, and lymph node involvement.
The survival rate after relapse is shorter than that of other types of breast cancer. Relapse rates are high in the first five years, with a peak at three years post-surgery. After that, the relapse rate declines significantly.
A 2007 study found that 77 percent of women with TNBC survived five years. Women with other types of breast cancer had a 93 percent five-year survival rate.
It’s worth noting that the majority of women treated for TNBC do not relapse.