FAQS: Triple Negative Breast Cancer
Q. I’ve been diagnosed with triple negative breast cancer. Is this a type of breast cancer like IDC or inflammatory breast cancer, or…?
A. No, it’s not a type of breast cancer like those you mentioned. You can have IDC and a triple negative diagnosis; or invasive lobular cancer, and be triple negative, too.
So, while IDC and ILC and DCIS are breast cancer sub-types, triple negative is a phenotype – that is, “triple negative” refers not to what the cancer is, but how it behaves.
And how does triple negative breast cancer behave? Well, it’s not cooperative, that’s for sure. “Triple negative” refers to the fact that your cancer cells are negative for estrogen and progesterone receptivity; and also negative for HER2-neu over-expression. Most women’s cancers are positive for at least one of those, giving them more treatment options.
Q. So this is a less-common type of breast cancer, then?
A. Actually, about 17% of women with breast cancer have triple negative cancer. It’s generally considered more aggressive; and it’s more common in younger women; in African–American women, and in women with BRCA1 or BRCA2 gene abnormalities.
Q. How will this diagnosis impact my treatment? Will I have surgery and radiation and chemo and all of that?
A. Yes, you’ll have the usual treatment (surgery, perhaps radiation, and definitely chemo). If the cancer has spread to your lymph nodes, you’ll probably have chemo prior to surgery, to track how effectively it shrinks the tumor.
What you won’t have is long-term drug treatment. Unfortunately, your cancer doesn’t depend on estrogen or progesterone to grow, as most breast cancers do. So denying your cancer access to those female sex hormones, via tamoxifen or an aromatase inhibitor, won’t stop it from growing.
Likewise, it doesn’t “over-express” the HER2-neu protein. And while this over-expression in and of itself isn’t a plus (HER2-neu over-expression signals a more aggressive cancer), it does mean women with this type of cancer can be successfully treated with the drug Herceptin.
Bottom line: Most women have ER/PR-receptive breast cancer, and receive long-term hormone-repression therapy to reduce their risk of recurrence. Women with HER2-neu positive breast cancer take Herceptin for a year, to reduce their risk of recurrence. For women with triple negative breast cancer, there’s no therapy beyond chemo that will help you keep the cancer at bay.
Q. Well, that doesn’t sound good….
A. Luckily, chemotherapy is generally quite effective for women with triple negative breast cancer – in fact, more effective than it is for most other diagnoses. You’ll receive chemo for sure, since you need to attack this cancer with everything available – which is chemo.
Most women with a triple-negative diagnosis receive ACT: Adriamycin (an anthracycline), Cytoxan (a cyclophosphamide), and Taxol (a taxane). Hopefully that’ll knock the cancer out for good. Two newer drugs in the pipeline, carboplatin and cisplatin, are showing promise as perhaps being more effective than ACT. Currently, they’re only being used to treat metastatic TNBC.
Q. What if chemo doesn’t work?
A. You’ll most likely find that out sooner rather than later. Women with a triple negative diagnosis are more likely to suffer a recurrence within the first three years than women with hormone-receptive or HER2-neu-positive cancer. In fact, the recurrence rate for TNBC is about 32% in the first 5 years, compared to around 15% for women with other breast cancers. If you can get through those first 5 years after treatment cancer-free, then your chances are excellent that you’ve beat it.
Q. And if the cancer comes back…?
A. There are other treatments on the horizon, some closer to becoming reality than others.
The use of the drug Avastin in conjunction with chemo has had good results in clinical trials, and has actually been approved by the FDA for use in advanced breast cancer. Avastin, a co-called antiangiogenic drug, keeps tumors from growing the blood vessels they need to ensure a steady blood supply.
One of the most popular diabetic drugs in the U.S., metformin (a.k.a. Glucophage, Fortamet, et. al.), has had extremely positive results against all types of breast cancer, including triple negative, when given at low levels with chemo drug Adriamycin. While still in Phase III clinical trials, the combination of these two drugs both eliminated tumors, and prevented their regrowth; while Adriamycin alone simply kept the tumors from growing, without fully eliminating them.
Another promising treatment is a class of drugs called PARP inhibitors. PARP1 is a gene involved in helping cells recover from the natural damage they incur as they grow. If this gene is inhibited – prevented from doing its job – cancer cells are unable to repair themselves, and they die.
A possible future treatment, currently in phase II clinical trials, is the drug Tarceva®, an EGFR inhibitor. EGFR (epidermal growth factor receptor) helps cells grow and proliferate; when it’s “inhibited” (disabled), cancer cells can’t grow.
Finally, a phase II trial using bisphosphonates – the drugs commonly used to treat osteoporosis – to inhibit the spread of TNBC to the bones has shown promising results.
Q. I still feel like I drew the short straw here…
A. A diagnosis of triple negative breast cancer, with its lack of multiple treatment options, may seem devastating at first. But researchers are making huge strides in discovering new ways, beyond hormone therapy and Herceptin, to stop the spread of all breast cancers.
And treatment for triple negative cancers are definitely getting front-burner treatment. As oncologist Mark Pegram, M.D., of the Sylvester Comprehensive Cancer Center in Miami notes, once researchers discover what TNBC is, rather than what it isn’t, “We’ll stop calling it triple-negative and start calling it something positive.” Just as Herceptin was developed to treat HER2-neu cancers – once their “Achilles heel” was identified – the same will be true for TNBC.
For more information, connect with the Triple Negative Breast Cancer Foundation. For professional support services by phone, call TNBC, 877.880.8622.