Treating Metastatic Breast Cancer
There are two primary goals for treating metastatic breast cancer: controlling the cancer and controlling side effects and symptoms of the cancer and its treatments for as long as possible.
Your medical oncologist will be the person who has the job of controlling the cancer. A palliative care provider is someone who specializes in pain control. Palliative care can play an important role in improving your quality of life by helping to keep symptoms, side effects, and collateral damage under control.
You are likely to have a number of treatment options. You are also likely to find that your treatments change over time. If and when your cancer stops responding to the treatment you are on, your oncologist will recommend new options. These options are likely to include clinical trials. These may be large phase III trials or they could be smaller phase I or phase II trials in which you are one of the first people to try a new treatment. Some of these trials may be testing new types of targeted therapies that require you to have a metastatic site biopsied. This will allow the researchers to determine whether your tumor has the specific mutation or biological marker that makes it more likely to respond to the therapy.
Some of the newer treatments for metastatic breast cancer have been found to improve the time before the cancer begins to progress better than some of the older chemotherapy and hormone options. (In clinical trials, this time before a cancer progresses is referred to as “disease-free survival.”) Be sure not confuse “increased time to progression” with “increased survival.” Some treatments may do both. But just because a drug gives you more symptom-free time before the cancer recurs, doesn’t mean the drug will actually help you to live longer. Instead, it is more likely that you will live comfortably for a longer time and spend less time actually ill. Of course, living longer also is important. But you should know what a treatment can and can’t do.
The types of treatments for metastatic breast cancer include:
Hormone (Endocrine) Treatments
In women who have metastatic disease and a tumor that’s sensitive to hormones, using endocrine treatments before using chemotherapy often makes more sense, at least in the beginning, while the tumor still responds to these treatments. When a patient has responded to one hormone therapy, we know she’s likely to respond to a second and possibly a third one—or occasionally more—so we use them in sequence.
Breast cancer responds to many different kinds of chemotherapy drugs. Currently, 13 chemotherapy drugs are used commonly to treat breast cancer. Indeed, chemotherapy is the best choice for women whose tumors are not responsive to hormone therapy or have stopped responding to hormone treatment. Importantly, chemotherapy can reduce symptoms from metastatic disease even better than narcotics. These drugs are usually used in women with ER and PR negative tumors, and women who need a rapid response because the metastases are causing organ dysfunction. Symptoms generally improve within a few weeks. The average duration of the response is five to 13 months on the drug, but individual patients’ responses can last longer. Which drugs your oncologist will recommend will depend on what, if any, chemotherapy you have already had.
Many chemotherapy drugs produce the standard side effects (vomiting, bone marrow suppression, etc.), and when the drugs are combined these tend to be worse. For this reason, giving one chemotherapy drug at a time can significantly reduce side effects. Most chemotherapy drugs involve some hair loss. Most will decrease your white cell count.
Targeted therapies are drugs that target other molecules that might be specific to or overexpressed by the cancer cells. If your tumor is HER2-positive, you will be offered a HER2-targeted therapy.
There are many other targeted therapies in development. Your oncologist may talk to you about a new drug or a drug in a clinical trial that targets proteins or mutation such as PI3K, mTOR, CDK, IGF-1, HDAC, FGF, HSP, PARP, and others. All of these drugs are examples of what doctors mean when they talk about “personalized” or “precision” treatment. The goal is to find the treatment that is best for your specific tumor.
Vaccines for metastatic breast cancer are being tested in clinical trials and may be useful in the near future. Other approaches in immunotherapy include new drugs that block signals from the tumor that inhibit or prevent the immune system from working properly. These drugs, most of which are in clinical trial for metastatic breast cancer, change the way cells behave, allowing the immune system to play a stronger role in attacking the tumor cells.
Most breast cancer treatments kill or control the cancer cell. The other approach is to alter the tissue that the cancer cell is trying to grow in. Bisphosphonates, initially developed to treat osteoporosis, make it more difficult for the cancer cells to grow in the bone. They are used to prevent and treat bone metastases. These drugs also reduce the frequency of fractures and other bone symptoms.
Radiation for metastatic cancer is the same as for initial breast cancer, but its purpose is different—to alleviate pain or other symptoms. A couple of weeks usually pass before the pain noticeably lessens. After any treatment of any organ, and especially bone, healing of damage from the cancer must occur before fully normal function returns.
Surgery is best if there is one spot in the lung or brain, for example, in a woman who has had a reasonably long interval between primary diagnosis and development of metastatic disease. If the cancer has recurred in several places, however, systemic treatment is usually a better option.
In terms of palliation—getting rid of symptoms so you feel better—treatments of the cancer itself aren’t the only options. Anybody who has chronic pain because of metastatic cancer and isn’t getting relief should ask to be referred to a pain unit. Sometimes oncologists and people who work on cancer are so focused on treating and curing the disease that they forget about these ancillary things that can make an enormous difference in a patient’s life. So ask to see a pain specialist; even if it means having to travel to the local medical school. It can make a big difference to your quality of life.
Learn more about treatments for metastatic cancer in Recurrence.