What is Oligometastatic Breast Cancer?

In recent years, awareness and treatment options for oligometastatic breast cancer (OMBC) have grown. While any cancer diagnosis is difficult, learning about this specific type of breast cancer may offer a measure of hope. With targeted treatment, people with OMBC may live longer, higher-quality lives.

What is oligometastatic breast cancer?

First identified by researchers in 1995, OMBC is a distinct form of metastatic breast cancer. It is set apart by the number of tumors, the cancer cells' genetic makeup, and its rate of progression.^1,2

In typical metastatic breast cancer, cancerous breast cells spread to other parts of the body, most commonly the brain, bones, liver, and lungs. In contrast, OMBC is defined by having no more than five tumors, which are usually found in just one other organ. When metastatic breast cancer involves more than five tumors, it is known as polymetastatic breast cancer.^1,2

How common is oligometastatic breast cancer?

While the exact rate of OMBC is unknown, some experts believe that it may account for a significant number of new metastatic breast cancer cases.¹

The American Cancer Society projects 279,100 new cases of breast cancer in the United States in 2020. About 99 percent of these cases are expected to occur in women. The other 1 percent of cases are expected to occur in men.³

According to the Metastatic Breast Cancer Network, 155,000 people in the United States have metastatic breast cancer today. About 6 percent of people with metastatic breast cancer had it when they first learned they had cancer. OMBC accounts for 14,000 cases of breast cancer in the United States each year.^3,4

What are the treatments for oligometastatic breast cancer?

Distinguishing OMBC from other metastatic breast cancers is critical because the treatments and outcomes are different.

For years, there was not enough data to determine the best course of action. Doctors evaluated radiation, surgery, and systemic drugs (like chemotherapy) that treat cells throughout the body. While promising results were seen with radiation therapy confined to specific areas, many questions remained, which led to more research.¹

A study published in 2018 showed that immunotherapy combined with radiotherapy brings about improved outcomes for more people with OMBC. The study even calls the ablative radiotherapy used to directly destroy the cancer cells a possible cure for OMBC.⁵

Doctors and researchers who are dedicated to helping people with OMBC continue to carry out new studies. They are searching for new treatment options that will get rid of OMBC and increase survival rates. They also want to develop treatments with less toxic side effects to improve the quality of life for people with OMBC.^1,2,5

What are the outcomes for oligometastatic breast cancer?

The growing understanding of OMBC brings hope because studies are revealing better outcomes for this diagnosis compared to other forms of metastatic breast cancer. Research shows that people with OMBC often survive longer than those with polymetastatic breast cancer.^1,2

The American Cancer Society estimates that breast cancer will cause 42,690 deaths in the United States in 2020. Metastatic breast cancer causes 40,000 deaths in the United States each year.^3,4

If you have received a diagnosis of OMBC, know that hope and help are available. Treatment options are more targeted today than ever before. Your doctor can help you understand all the possibilities, including clinical trials, to make an informed choice and create the best treatment plan for your situation.