Triple Negative Breast Cancer: What Is It?
Understanding Triple Negative Breast Cancer
Triple-negative breast cancer (TNBC) is a type of breast cancer that does not respond well to hormone therapy. TNBC accounts for 15-20% of all breast cancers diagnosed each year. In fact, triple-negative breast cancer is the only subtype of breast cancer that cannot be treated with hormonal therapies. Hormonal therapies work by blocking estrogen receptors in order to stop tumor cells from multiplying. However, TNBC tumors do not have these receptors. Therefore, they do not respond to treatment with anti-estrogens.
What Is The Real Cause Of Triple Negative Breast Cancer?
There are several theories regarding what causes TNBC. One theory suggests that TNBC arises due to genetic mutations that lead to abnormal gene expression. Another theory suggests that TNBC results from epigenetic changes that affect how genes are expressed. A third theory proposes that TNBC may result from environmental factors, including exposure to certain chemicals or radiation.
How Does TNBC Affect Women?
Women who have TNBC tend to develop tumors at younger ages than women with other types of breast cancer. In addition, they may experience different symptoms than those associated with other forms of breast cancer. A diagnosis of triple-negative breast cancer requires a biopsy.
What are the Symptoms of TNBC?
Symptoms of TNBC may vary depending on the type of tumor. Symptoms of basal A tumors tend to occur earlier than those of basal B tumors. Common symptoms of basal A tumors include nipple discharge, swelling of the lymph nodes under the arm, pain in the armpit, skin irritation around the nipple, and bleeding after intercourse.
Common symptoms of basal B tumors include irregular menstruation, abnormal vaginal bleeding, abdominal bloating, weight gain, fatigue, nausea, vomiting, diarrhea, and loss of appetite. Other symptoms of TNBC may include fever, chills, night sweats, backache, chest pains, coughing, shortness of breath, bone pain, joint aches, headaches, eye problems, mouth sores, and changes in bowel habits.
- Changes in breast size – Breast cancer is not always detected early enough to prevent metastasis (spreading) to distant organs. When the tumor cells spread to the lymph nodes, they may cause swelling of the lymph glands under the armpit. If the tumor spreads to the chest wall, it may cause pain, thickening, and hardening of the skin overlying the affected area. In some cases, the tumor may press on nearby nerves and result in numbness, tingling, or burning sensations.
- Change in the menstrual cycle – Chemotherapy drugs affect the ovaries and interfere with the production of hormones. As a result, women who undergo chemotherapy treatments may experience irregular menstruation cycles.
- Loss of hair – Hair loss occurs in about half of all patients undergoing chemotherapy. Hair loss may begin at any time after diagnosis, but generally begins around the scalp and progresses downward. Women lose their hair first, then men.
- Weight gain – Weight gain is a side effect of many types of cancer therapy. Patients may feel tired and weak and may eat more than usual. Fatigue and weakness may last long after treatment ends.
- Nausea and vomiting – Nausea and vomiting occur frequently during chemotherapy. These symptoms may worsen if food smells bad or tastes bad. You may find yourself eating only liquids.
- Skin problems – Skin rashes, itching, dry skin, and sores may develop during chemotherapy. Your doctor may prescribe special creams or lotions to help relieve these conditions.
- Mouth sores – Chemotherapy drugs irritate the mouth lining, causing ulcers in the mouth and throat. Soreness and bleeding may occur.
- You may need additional tests – After breast cancer treatment, doctors sometimes recommend additional testing to make sure everything’s OK. Tests may include blood counts, bone scans, CT scans, mammograms, MRI exams, PET/CT scans, and ultrasound examinations.
What Causes TNBC?
- Genetics – One study showed that approximately 10 percent of patients with TNBC had a mutation in BRCA1 or BRCA2, two genes involved in DNA repair. However, many people with TNBC don’t carry any known mutations in those genes.
- Epigenetics – Another possible explanation for TNBC involves epigenetic changes. Epigenetics is the study of heritable traits. Epigenetic mechanisms control gene activity without changing the underlying DNA code. Scientists think that epigenetic changes could explain why some people inherit a predisposition toward developing TNBC.
- Environment – Some researchers suggest that TNBC may arise from environmental exposures. For example, studies show that women exposed to high levels of polycyclic aromatic hydrocarbons (PAHs), a class of carcinogens, were more likely to develop TNBC. PAHs are present in tobacco smoke and combustion products, such as car exhaust fumes. Other research shows that women who live near coal-fired power plants are more likely to develop TBC.
- Other Factors – Studies have shown that women who drink alcohol regularly are more likely to develop breast cancer. Obesity increases the risk of developing TNBC. Women who exercise frequently are less likely to develop TNBC than women who rarely exercise. And having children before age 30 reduces the risk of developing TNBC.
Treatment Options For TNBC
The good news is that TNBC is highly treatable. There are many different types of treatments that can be used to help patients with TNBC. These treatments include chemotherapy, radiation therapy, surgery, immunotherapy, targeted therapy, and others.
- Chemotherapy – kills the rapidly dividing cells. Chemotherapies are often given intravenously and may cause nausea, hair loss, mouth sores, fatigue, and diarrhea. Patients who receive chemotherapy should drink plenty of fluids to prevent dehydration.
- Radiation therapy – uses high doses of x-rays to destroy cancer cells. Radiation therapy is often combined with chemotherapy. Side effects of radiation therapy include skin irritation, dry mouth, and changes in taste.
- Surgery – involves removing the entire tumor or a portion of it. Surgery can be performed either before or after chemotherapy. If surgery is done first, then chemotherapy is administered afterward. After surgery, doctors remove any remaining cancerous cells.
- Immunotherapy – works by stimulating the immune system to attack cancer cells. Immunotherapy is sometimes called biological therapy. It is given directly into the bloodstream via injection. Common side effects include fever, chills, headache, muscle aches, cough, shortness of breath, and sore throat.
- Targeted therapy – targets specific molecules on the surface of cancer cells. Targeted therapy is often referred to as molecularly targeted therapy. Drugs that target HER2/neu are commonly used to treat TNBC.
There are several different types of targeted therapies. Examples include Herceptin, Avastin, Lapatinib, and Trastuzumab. Each drug works differently, but they all aim to block certain molecules on the surface of the cancer cells.
Triple-negative breast cancer (TNBC) is a type of breast cancer that does not respond well to hormone therapy, chemotherapy, or radiation treatment. TNBC accounts for about 15% of all breast cancers diagnosed each year. While some patients have good outcomes after surgery alone, others may need additional treatments to improve their prognosis.
Why should I know about triple-negative breast cancer?
Knowing about TNBC helps women understand how they can best treat themselves if they develop symptoms related to this disease. Women who have had a family history of breast cancer, especially first-degree relatives, are at increased risk of developing TNBC. Other factors associated with higher risks of developing TNBC include African American race/ethnicity, early menarche, late age at first live birth, nulliparity, obesity, alcohol consumption, and lack of physical activity.
What Foods Should I Eat to Help Fight Against TNBC?
A diet rich in fruits and vegetables can help fight against TNBC. These foods provide antioxidants that protect cells from damage caused by free radicals. Antioxidants also help reduce inflammation, which can cause problems with blood flow and lead to tumor formation.
What Foods Should I Avoid When Fighting Against TNBC?
Avoiding processed meats and red meat can help lower your risk of developing TNBC. Processed meats increase levels of estrogen, which can promote the growth of certain types of breast cancer. Red meat contains high amounts of iron, which can contribute to oxidative stress. Oxidative stress increases the risk of developing TNBC due to its effects on DNA.
Is There Hope?
Yes! Research shows that women who have had a lumpectomy followed by radiation therapy appear to experience fewer local recurrences than those who receive only mastectomy. Women with triple-negative breast cancer should discuss their treatment options with their doctors.