Metastatic Breast Cancer

Breast Cancer

Metastatic breast cancer refers to the advanced form of breast cancer that has spread from its site of origin to distant organs. This form of breast cancer is designated as stage IV and has a poor prognosis.

This refers to the stage of breast cancer in which cancer cells from the breast have travelled to another part of the body. Bones, liver, and lungs are the most common sites to which breast cancer cells spread. Breast cancer detected at this stage is not curable.

Symptoms of metastatic breast cancer 

Other than the normal symptoms of breast cancer like development of lump in breast and other changes associated with its appearance, there are several other symptoms, which may indicate metastasis. These are the following:

  • Bone metastases is indicated by bone fracture and pain
  • Lung metastases is indicated by breathing difficulties
  • Liver metastases is indicated by weight loss and lack of appetite
  • Neurological metastases is indicated by headaches, seizures, weakness, and nausea

Organs to which breast cancer cells mostly spread

Bone: Around one-fourth of metastatic breast cancer leads to bone cancer. These are of two types:

Osteolytic cancer: Holes are formed in the bones, which leads to bone fractures. It causes severe pain.

Osteoblastic cancer: Density of the bones increases in this case, which makes them prone to fractures and breaks. It also causes severe pain.

Lung: Most deaths associated with metastatic breast cancer is due to the metastasis of the breast cancer cells to lungs.

Liver: Metastasis of breast cancer cells to liver is associated with two-thirds of metastatic breast cancers.

Brain: Breast cancer cells also spread to the brain in some cases.

Diagnosis

  • Clinical breast exams: This is the physical examination of the breast done by the doctor.
  • Mammogram: This imaging technique uses X-rays to produce images of soft tissue of the breast.
  • Chest X-ray: The chest x-ray remains probably the most valuable tool in diagnosing metastatic breast cancer.
  • Bone scan: A bone scan or bone scintigraphy is an imaging test used to determine metastasis of breast cancer cells to the bones. A radioactive substance is injected into a vein in one arm before the scan begins.
  • CT scan: It is an imaging procedure of the internal organs of the body with the help of X ray machine attached to a computer.
  • MRI scan: The imaging technique is based on the use of a strong magnetic field and radio waves. The images can be viewed on a computer screen. It helps to diagnose the size and location of the cancer.

Biopsy: Cells or small piece of tissue collected from the affected regions are viewed under a microscope to detect their characteristics.

Treatments for Metastatic Cancer

Metastatic breast cancer can have different modes of treatment, but systemic therapy is the best approach to treat metastatic breast cancer.

Surgery and Radiation therapy:

Surgery and/ or radiation therapy may be useful only for selected patients. Conditions for which this kind of therapy can be applied are:

Open wounds in the breast, limited metastases, bone fractures, pressing of the overgrown region on the spinal cord, liver blockage, pain, bronchial obstruction, lung, and brain metastases.

Strontium 89 can be administered to treat diffuse bony metastases.

Regional chemotherapy:

This therapy is applied in some cases where drugs directly reach the affected site.

Systemic Therapy:

Systemic therapy is the best mode of treatment for metastatic cancer for reducing the size of tumor, increasing life expectancy and relieving pain, but does not cure cancer and may include the following:

Hormone therapy: Patients with estrogen or progesterone receptor positive tumor can undergo hormone therapy. Tamoxifen is frequently used for this purpose. It blocks the effects of estrogen. There are also drugs called aromatase inhibitors that prevent estrogen from being made by postmenopausal women, who still produce small amounts.

In premenopausal women with metastatic breast cancer, estrogen production can be blocked by medication, or the ovaries can be removed.

One-fourth of breast cancer patients show higher expression of HER2/neu. Trastuzumab is a humanized monoclonal antibody that binds to the HER2/neu receptor. It can be administered in combination with chemotherapeutic agents or with the hormone therapy drug letrozole. Lapatinib (Tykerb), another agent for hormone therapy also blocks the activity of the HER2 protein.

Therapy to relieve pain: Bisphosphonates like pamidronate (Aredia) or zoledronic acid (Zometa) are used to reduce skeletal morbidity in patients with bone metastases. Calcium and vitamin D, along with these drugs are also recommended. Pain from bone metastases may also be treated with radiation.

Cytotoxic chemotherapy

Cytotoxic chemotherapy can be provided to patients whose tumors have progressed on hormone therapy. Patients with Her 2 negative tumors and visceral metastases can be treated with cytotoxic drugs such as Doxorubicin, Epirubicin, Mitoxantrone, Paclitaxel, Docetaxel, Cyclophosphamide, Capecitabine, 5-FU, Methotrexate, Vinorelbine, Cisplatin, Mitomycin C, and Gemcitabine in various combinations.

Prognosis

Prognosis of metastatic breast cancer depends on the extent of spread of the breast cancer cells, type or organ to which secondary cancer has developed, time between treatment and relapse, and a patient’s general health. Proper treatment is essential for increasing the time of survival after detection. Most patients liver for another 2-3 years, some for 5 years and rarely a very few live for 10 years. The five-year survival rate for Stage IV metastatic breast cancer is around 15%.

References

  1. Lang R, Fan Y, Fu X, Fu L. (2011) Metaplastic breast carcinoma with extensive osseous differentiation: a report of two cases and review of the literature. Tumori.;97(4):0. doi: 10.1700/950.10411.
  2. Adisa AO, Arowolo OA, Akinkuolie AA, Titiloye NA, Alatise OI, Lawal OO, Adesunkanmi AR. (2011) Metastatic breast cancer in a Nigerian tertiary hospital. Afr Health Sci.;11(2):279-84.
  3. Fornier MN. (2011) Approved agents for metastatic breast cancer. Semin Oncol.;38 Suppl 2:S3-10.
  4. Cobleigh MA. (2011) Other options in the treatment of advanced breast cancer. Semin Oncol.;38 Suppl 2:S11-6.

This article was originally published on September 3, 2012 and last revision and update was 9/4/2015.