Navigating Treatment Options for Metastatic Breast Cancer

First Line Therapy Options for Metastatic Breast Cancer

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What treatments are available for metastatic breast cancer and which therapies are often used first line?. Hero Images / Getty Images

Before talking about all of the specific treatments which you may choose for metastatic breast cancer, it helps to talk about the types of treatments, the goals of treatment, and what particular treatments are often used first to address metastatic cancer.

Types of Cancer Treatments

Even though we now have many different types of treatment for cancer, these can be broken down into two main categories.

Local treatments – Local treatments address cancer in the place in which it begins (or in a single metastasis to an organ.) These treatments include:

  • Surgery
  • Radiation therapy

Systemic treatments, in contrast, address cancer cells wherever they happen to be in the body. These include:

For metastatic breast cancer, systemic treatments play the largest role in treatment. Local treatments such as surgery or radiation are used primarily to treat metastases when these are causing symptoms, such as bone metastases which pose the risk of fractures or metastases to the skin or chest wall which are bleeding and painful.

Many people wonder why breast surgeries such as a lumpectomy or mastectomy are not often done in people who have metastatic breast cancer, at least for the five to ten percent of people who have metastatic cancer at the time of diagnosis.

The reasoning for this is that with metastases, the cancer has already spread well beyond the breast.

These treatments are unable to potentially cure a cancer which has spread. Instead, surgery—due to recovery times and immune system suppression—might mean delaying systemic therapies, which ultimately play the largest role in treating your cancer.

“Lines”of Treatment

You will probably hear your doctor talk about “first line treatment,” “second line treatment,” and so forth. This term simply means the first treatment or treatments, second treatments, and so on which may be used sequentially to treat your cancer.

It is very common with metastatic breast cancer to have several different “lines” of treatment. First line treatment is usually selected based on what treatments are most likely to be successful with the fewest side effects, but there are many options available.

Factors Which Influence the Choice of Treatments

There are many factors which may be considered in choosing the right treatment for your cancer, both initially, and as time goes on. Some of these include:

  • Receptor status of the tumor
  • Previous treatments (breast cancers often become resistant to a treatment over time)
  • Tumor burden (how extensive your tumor(s) are and how large)
  • The specific symptoms you have related to your cancer and how bothersome these are for you
  • How fast the cancer is progressing
  • Your personal preferences for ease of treatment (oral vs IV for example), and tolerance of side effects (some people find some side effects more distressing than others)
  • Whether or not you are taking part in a clinical trial

    Typical First-Line Treatments for Metastatic Breast Cancer

    Everyone with metastatic cancer is different, and every cancer is different so it is difficult to talk about a “typical” cancer treatment. That said, the first treatments chosen for metastatic cancer are often related to the hormone receptor status of your cancer.

    These treatment approaches will depend on your receptor status after a “rebiopsy” of your tumor or a metastasis, not what your receptor status was when you were first diagnosed if your tumor is a recurrence. If your original cancer was estrogen receptor positive, it may now be negative, and vice versa.

    Again it’s important to note that the goal of treatment for metastatic cancer is usually to use the least amount of treatment possible to stabilize and control the disease. This is different than the “curative” approach used with most early stage breast cancers.

    Examples of possible first line treatments based on receptor status include:

    Estrogen receptor (ER) positive metastatic breast cancer

    The first treatment for estrogen receptor positive breast cancer is usually hormonal therapy, and this is often used alone. The choice of drugs will depend on whether you were on hormonal treatment when your cancer returned.

    For premenopausal women, tamoxifen is needed since the majority of estrogen produced by the body is from the ovaries. Alternatively, ovarian suppression with either Zoladex (goserelin) or less commonly, removal of the ovaries, may be followed by treatment with either tamoxifen or one of the aromatase inhibitors.

    For postmenopausal women, one of the aromatase inhibitors is usually used alone, unless a recurrence occurred while using one of these medications. If your tumor recurred while on an aromatase inhibitor, a different option may be using the anti-estrogen drug Faslodex (fulvesrant).

    If your tumor is estrogen receptor positive but is progressing rapidly, there are several options. If your tumor is also HER 2 positive, a HER 2 targeted therapy may be added to hormonal therapy. Chemotherapy may also be used in addition to hormonal therapy for those who have tumors which are growing rapidly.

    If you have significant symptoms related to metastases, other treatments may be added in as well. For bone metastases, radiation therapy or a bone-modifying drug may be used to lower the risk of a fracture, spinal cord compression, or to treat severe pain.

    Likewise, metastases to the lungs causing bleeding or obstruction, or brain metastases which are causing significant symptoms may also be treated with local therapies such as radiation or surgery.

    HER 2 positive metastatic breast cancer

    If you have a tumor which is estrogen receptor positive and HER 2 positive, first line treatment may begin with hormonal treatment alone or the combination of a hormonal drug and a HER 2 positive drug.

    First line treatment for HER 2 positive metastatic breast cancer also depends on whether or not you were being treated with one of these medications when you experienced a recurrence. If your cancer recurred while on Herceptin, one of the other HER 2 medications may be used. If your tumor is growing rapidly, chemotherapy may be considered.

    As with estrogen receptor positive tumors, symptomatic metastases may require local treatment as well. For example, painful bone metastases or metastases which increase the risk that you could fracture a bone may be treated with radiation therapy or a bone-modifying agent.

    Estrogen receptor negative, progesterone receptor negative and HER 2 negative tumors (triple negative breast cancer)

    Triple negative metastatic breast cancer is more difficult to treat, in general than breast cancers which are estrogen receptor or HER 2 positive, but there are still options.

    Chemotherapy is often used first line for these cancers, and the choice of medications often depends on whether chemotherapy was used previously.

    (Learn why​ ​targeted therapies don't work for triple negative breast cancer.)

    Metastatic breast cancer in men

    Metastatic breast cancer in men has several important differences, but in general, the same approach is taken. Treatment may begin with tamoxifen for those who have estrogen receptor positive tumors, or with chemotherapy.

    A Word From Verywell

    The examples of possible first line treatments above are only examples, and your oncologist may recommend a different approach based on the characteristics of your unique tumor. Many drugs are being evaluated in clinical trials, and one of these approaches may offer a different approach.

    The important thing is to talk with your doctor about why certain drugs would be recommended and to understand these choices as well as possible alternatives. Many people also find it helpful to ask about the treatments which would be recommended if this particular regimen does not control their tumor.

    Being one step ahead in your mind may help you cope just a little easier with the anxiety related to the unknowns ahead.


    Hayes, D. Patient education: Treatment of metastatic breast cancer (Beyond the Basics). UpToDate. Updated 12/07/16.

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