July 2015 Ask the Expert: Medical Updates, Treatment Options and Follow-Up Care for Triple-Negative Breast Cancer
This July, Living Beyond Breast Cancer expert Rita Nanda, MD, answered your questions about triple-negative breast cancer – how it's different from other types of breast cancer, what treatments are available, what research is happening and how it applies to you.
Remember: we cannot provide diagnoses, medical consultations or specific treatment recommendations. This service is designed for educational and informational purposes only. The information is general in nature. For specific healthcare questions or concerns, consult your healthcare provider because treatment varies with individual circumstances. The content is not intended in any way to substitute for professional counseling or medical advice.
Dr. Nanda: One in eight women in the US will develop breast cancer in her lifetime and about 20 percent are triple-negative. While there are a number of risk factors that are known to increase risk, such as having a BRCA1 or BRCA2 mutation, up to 80 percent of women who develop breast cancer have no identifiable risk for developing breast cancer. And it is not well understood why some women develop triple-negative breast cancer versus other types of breast cancer.
Dr. Nanda: The risk of recurrence of triple-negative breast cancer (as is the case for other forms of breast cancer) is related to the size of the tumor, the number of lymph nodes that are positive for cancer, and the grade of the tumor. In general, the larger the tumor and/or the higher the number of involved lymph nodes, the higher the risk of recurrence.
Dr. Nanda: Processed foods do not selectively feed cancer cells. We do advise patients to follow a heart-healthy diet and some studies suggest that such a diet can reduce the risk of recurrence. General recommendations are for a low fat, high fiber diet, focusing on lean sources of protein (grains, fish, turkey, chicken over more fatty sources of protein; baked foods over fried) and plenty of fresh vegetables and fruits. In addition, reducing or limiting alcohol consumption to under three alcoholic beverages (on average) a week has also been show to help reduce the risk of breast cancer recurrence. Rich foods, sweets and alcohol are fine in moderation.
Dr. Nanda: Maintaining a healthy body weight, following a heart-healthy diet and exercising regularly have all been associated with a reduction in the risk of recurrence of breast cancer in a number of different studies. While it is hard to know to what degree these lifestyle changes reduce the risk, a number of studies have demonstrated a benefit and it is never too late to start healthy habits!
Dr. Nanda: Psychological stress describes what people feel when they are under mental, physical, or emotional pressure. Although it is normal to experience some stress from time to time, people who experience high levels of stress over a long period of time may be at increased risk for developing health problems. However, there are no clear data linking stress to the development of cancer.
People who have cancer may have increased stress related to the diagnosis and treatment of the disease. People who are able to use effective coping strategies to deal with stress, such as relaxation and stress management techniques, have been shown to have lower levels of depression, anxiety and symptoms related to the cancer and its treatment. Although there is still no strong evidence that stress directly affects cancer outcomes, studies suggest that patients can develop a sense of hopelessness when stress becomes overwhelming. It is therefore important for those who are experiencing symptoms of stress to seek help.
Dr. Nanda: The chemotherapy drugs that are routinely used to treat TNBC are drugs that have been around since the 1980s and 1990s. These drugs are generally well-tolerated, with manageable side effects. While our treatments haven’t significantly changed for the past 2 decades, our ability to manage the side effects has. Anti-nausea medications have improved and the vast majority of women who receive chemotherapy these days have little to no nausea. While fatigue, decreased blood counts and hair loss do occur with most regimens, these side effects are manageable.
Dr. Nanda: Zoledronic acid is a bisphosphonate, and bisphosphonates are routinely used to prevent or treat osteoporosis. Bisphosphonates do this by limiting the activity of certain bone cells, called osteoclasts, which help cause the bone weakening and breakdown that leads to osteoporosis. Investigators have also studied if bisphosphonates can reduce the risk of breast cancer recurrence. The studies performed to date have had mixed results, with some demonstrating a reduction in the risk of recurrence and others showing no reduction. A meta-analysis (an analysis of all of the studies lumped together) suggested that there is a modest reduction in the risk of relapse when bisphosphonates are given to women who are postmenopausal. While the use of bisphosphonates in this setting is somewhat controversial (given the conflicting results of the many studies performed), it is reasonable to consider its use, particularly in individuals who are postmenopausal and at high risk of recurrence.
Dr. Nanda: The risk of recurrence from breast cancer is based on the size of the cancer and lymph node status. While those who do not have lymph node involvement are at lower risk, there is still a risk of disease recurrence (your oncologist can help assess what your risk is based on your personal history and the features of your cancer). Chemotherapy can reduce this risk of recurrence by 50 percent. Therefore, even in the setting of negative lymph nodes, chemotherapy is routinely recommended for TNBC.
Dr. Nanda: The risk of recurrence after a diagnosis of breast cancer is related to the stage of the breast cancer (which is dependent on the size and the lymph node status). If TNBC recurs, the most common sites of recurrence include the lungs, the liver and the bones. Choosing to have a mastectomy or a double mastectomy does nothing to impact this risk of a recurrence. The primary medical reason for a person to consider prophylactic removal of both breasts is if she is found to be at high risk for developing a new breast cancer (e.g. if she has a BRCA1 or BRCA2 mutation).
Dr. Nanda: Immune checkpoint inhibitors have shown promise for women with advanced triple-negative breast cancer and studies exploring these agents alone or in combination with chemotherapy in the advanced cancer setting are ongoing. These drugs are purely investigational at this point, are not yet FDA approved for breast cancer, and thus not recommended outside of a clinical trial. Immune checkpoint inhibitors are being incorporated into therapy for early-stage disease in the neoadjuvant setting, and many studies for advanced cancer do allow patients with regionally advanced disease or locally recurrent disease that has not responded to standard chemotherapy.
Dr. Nanda: Breast cancers can be very heterogeneous and biopsies only sample a small area of the tumor, so they might not be representative of the entire tumor. I do think, however, that it would be reasonable to have both the first biopsy and the mastectomy specimen restained for ER, PR, and HER2 to confirm the result, given the differences between the two samples.
Dr. Nanda: Results from an early phase trial has suggested that targeting the tumor microenvironment with a copper-depleting agent, tetrathiomolybdate, creates an inhospitable environment for tumor progression in patients with breast cancer, with the effect most striking in those with triple-negative disease. The results were presented at the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting. Study investigators are currently developing a phase III randomized study of tetrathiomolybdate in breast cancer patients, but this study is not yet recruiting. Once it is, it will be listed on ClinicalTrials.gov. Tetrathiomolybdate is not FDA approved and is not available outside of a clinical trial.
Dr. Nanda: The American Society of Clinical Oncology (ASCO) has guidelines for follow-up care of breast cancer patients. After treatment is completed, patients should follow up with their physicians for physical examinations every 3-6 months for the first 3 years, every 6-12 months for years 4 and 5, and annually thereafter.
For women who have undergone breast-conserving surgery, a post-treatment mammogram should be done 1 year after the initial mammogram and at least 6 months after completion of radiation therapy. Unless otherwise indicated, a yearly mammographic evaluation should be performed.
The use of complete blood counts, chemistry panels, bone scans, chest x-rays, CT scans, PET scans, MRIs, and/or tumor markers (CA 15-3 and CA 27.29) is not recommended for routine follow-up in a patient with no symptoms and no specific findings on clinical examination. Some medical oncologists perform follow-up scans and tumor markers after the completion of treatment to monitor for a recurrence, however, intense surveillance has not been shown to improve outcomes for women with breast cancer, and I personally follow the ASCO guidelines. In fact, in many cases, intense surveillance can be quite detrimental as it can increase anxiety and lead to additional and oftentimes invasive and unnecessary testing.