Treatment for Metastatic Disease

In this phase of breast cancer treatment, the goal is to extend high quality of life as long as possible.  No one can tell how long you will live with metastatic breast cancer.  For some patients, having breast cancer and being treated for it becomes a chronic disease.  Other breast cancers are more aggressive or less responsive to treatment.  Many options are available today to treat metastatic breast cancer.  Your doctors will try to find one that fits your circumstances and works for you, and you will take it for as long it continues to be effective and tolerable.  If the treatment works, you will go into remission, which is when the cancer appears to be completely gone, partially disappears or remains stable.  Once a treatment stops working, your doctor will recommend another approach, and you will stay on that for as long it continues to work.

The overall goal of treating metastatic breast cancer is to control its growth, but if it causes symptoms in a specific place or organ, the doctor will treat those symptoms with a locally directed therapy.

During this phase of treatment, communicate with your doctor about what is important to you.  You can always find a balance between choosing the most aggressive treatments that have the greatest chance of controlling the cancer and minimizing the side effects.  You need to talk to your treatment team and let them know your priorities throughout the treatment process.  These priorities may change, so communication with your doctors needs to be ongoing, open and honest.
 

Hormone Therapy for Metastatic Breast Cancer
If your metastatic breast cancer is hormone receptor positive(ER+ and/or PR+), hormone therapy is often the first treatment. It has proven effective, can be used for many years and has fewer side effects than most other forms of systemic therapy.  The mechanisms for hormone therapy and the various drugs used for this purpose are explained in the Hormone Therapy section.
 

Chemotherapy for Metastatic Breast Cancer
Many drugs and combinations of drugs are used to treat metastatic breast cancer.  Your doctor will recommend some form of chemotherapy if you are hormone receptor negative (ER- and PR-); if you are estrogen receptor positive but your cancer has spread despite receiving hormone therapy; if your cancer has spread to your liver or throughout your lung tissue, known as lymphangitic spread; or if you are HER2 negative (HER2-).  Women with triple negative breast cancer usually receive chemotherapy both as adjuvant treatment following surgery and for metastatic disease.
 

Herceptin (trastuzumab) for Metastatic Breast Cancer 
Approximately 25% of women with invasive breast cancer are HER2 positive (HER2+), meaning that their tumors over express a protein made by the HER2 gene that helps regulate cell growth.  HER2+ tumors are generally more aggressive and more likely to recur.  The HER2 gene, however, provides a target for cancer therapy.  Targeted therapies work differently from standard chemotherapy.  Chemotherapy drugs usually kill cells that are actively dividing and growing – like most cancer cells – but they also kill normal cells that are in the process of growing and dividing.  Targeted therapies kill only cancer cells by directing their action to a genetic mutation or characteristic that is found in the cancer cell but not normal cells.

Herceptin was among the first targeted therapies used to treat cancer.  It was developed to treat breast cancer, although it has proven to be useful for a number of other cancers.  Herceptin works only for patients with HER2+ tumors.  It has contributed significantly to lowering rates of recurrence for women with early stage cancer and to prolonging life for those with metastatic disease.  In most cases, Herceptin is combined with one or more chemotherapy drugs.  An advantage of Herceptin is that, if one combination stops working, it can be used with other drugs and remain effective.  It can take several months before the positive effects of Herceptin become apparent. Some breast cancers even appear to worsen before the drug takes effect.  Herceptin can be taken indefinitely – for as long as it works to control the cancer.

Herceptin does have side effects, although they are generally mild.  They include upset stomach, allergic type reactions, flu-like symptoms and sometimes a localized sensation of burning on the skin near where the drug is injected.  Herceptin does not cause hair loss, although some of the drugs given with Herceptin may have that side effect.  The most serious side effect of Herceptin is heart failure, which occurs in 2-5% of patients who receive it.  For this reason, Herceptin is never given at the same time as Adriamycin (doxorubicin), another drug that can cause heart problems.

Next: Managing Side Effects and Pain.