Stage IV breast cancer prognosis

Prognosis means the likely outcome or course of a disease. If you’ve been diagnosed with stage IV metastatic breast cancer (MBC), you may have already learned that it means being in treatment for life. It’s completely understandable to want to know how long that really is.

Predicting how long a person might live after a stage IV MBC diagnosis depends on many factors. Your age and your health before cancer contribute as much as the details of the cancer, including where the cancer traveled, how much cancer there is, the cancer’s unique characteristics, and how well the cancer responds to treatment.

“The diagnosis of metastatic breast cancer is devastating and overwhelming,” says Douglas Yee, MD, breast cancer oncologist at University of Minnesota. “The first question that frequently comes to the forefront is, ‘how long am I going to live’? Most physicians can quote statistics (and statistics are searchable from ‘Dr. Google’), but those statistics are based on a population of women and men and do not necessarily predict how each patient will do as an individual. As each person is different, each tumor is also different. Therefore, the course of metastatic breast cancer, and its treatment, is also different.”

“It is important to understand the subtype of breast cancer, as well as the clinical features and certain molecular aspects of the tumor,” says Dr. Yee. “There are questions to be considered, such as ‘where has it spread? How long has it been since the last adjuvant therapy?’ Additionally, new therapies for metastatic breast cancer are under investigation at a rapid pace, making older data from population statistics less relevant. Taken together, it makes it almost impossible to precisely predict any individual’s prognosis, and a discussion of ‘what is possible?’, ‘what have you seen?’, and ‘what are our goals?’ is a good place to start a conversation with your doctor.”

On this page, we’ll talk about factors that impact an MBC prognosis and share some statistics on life expectancy. Not everyone finds this kind of information helpful. If instead you’d like to read more about treatment advances, or stories of other women living with MBC, we recommend our page on metastatic breast cancer treatments and our blog.

Here is what we currently know about stage IV MBC incidence in the U.S.:

• The American Cancer Society’s Breast Cancer Facts & Figures 2019-2020 reports that as of 2019, 150,000 women in the U.S. were living with metastatic disease. According to the report, three-fourths (75 percent) of these women were first diagnosed with early-stage breast cancer. This suggests that one-fourth (25 percent) of these women had MBC as their first-ever diagnosis of breast cancer (called de novo metastatic breast cancer). However, the American Society of Clinical Oncologists (ASCO) reports that only 6 percent of women have MBC when they are first diagnosed. This is one example of the sometimes-conflicting data tracking and information about MBC incidence in the U.S. — and why it’s important to talk with your doctor about your own individual situation and what that means for you.
• Men can also have MBC. While there is no estimated number of men living with MBC, men tend to be diagnosed at higher stages, and experts estimate 530 U.S. men will die of breast cancer in 2022.

What we don’t know about stage IV MBC incidence:

• Exactly how many people are living with stage IV MBC that is a recurrence of an early breast cancer.
• How long people live between an early breast cancer diagnosis and a metastatic recurrence

Researchers are trying to learn more to answer these questions.

Although MBC is not curable, it is treatable. People are living longer with metastatic disease now than ever before. This is because of ongoing research to produce new, more effective types of treatment, broadening your options for controlling the cancer as well as its symptoms and side effects.

Survival rates for metastatic breast cancer

Survival statistics are meant to help researchers understand how breast cancer impacts large groups of people, and to set a baseline for researchers looking at whether people are living longer or better with a certain disease. As discussed above, remember that the numbers in this section may not represent your own experience. It takes time to track and record survival rates, so they often don’t reflect survival with the newest treatment options.

The National Cancer Institute (NCI) and the North American Association of Central Cancer Registries (NAACCR) gather information on people in the U.S. diagnosed with breast cancer on an ongoing basis. The information is made widely available through the Surveillance, Epidemiology, and End Results (SEER) database of the NCI.

Breast cancer survival rates are reported as 5-year survival rates, which are calculated by comparing how likely people with breast cancer are to be alive 5 years after diagnosis to similar people without cancer. You can read a more in-depth explanation of 5-year survival on our Life expectancy page.

Survival rates for stage IV, metastatic breast cancer, depend on many things, including hormone receptor status and HER2 status, gender, and age:

5-year relative stage IV breast cancer survival rate by characteristics of the cancer

• Hormone receptor-positive/HER2-negative                 31.9%
• Hormone receptor-negative/HER2-negative                 12%
• Hormone receptor-positive/HER2-positive                   46%
• Hormone receptor-negative/HER2-positive                  38.8%

5-year stage IV breast cancer survival rate by gender

• Women       29%
• Men              22%

5-year stage IV breast cancer survival rate by age (women only)

• Ages <50              37.6%
• Ages 50-64          28.2%
• Ages 65+              23.1%
• All ages                 28.1%

Despite the strength of SEER data, MBC statistics can be hard to interpret and report. This is because many cancer registries that give their patient information to SEER only report cases of de novo MBC, meaning the cancer was metastatic at first diagnosis. But we know that some women diagnosed with early-stage disease will have the cancer come back as metastatic disease. These cases of recurrent MBC are usually not accounted for in SEER data. This means more people may be living with, or dying from, MBC than SEER data show.

Each person living with MBC is unique. If you’ve been diagnosed with MBC and are concerned about prognosis, have an honest conversation with your doctor about your individual situation. Over time, you and your doctor will have ongoing discussions about your treatment plan, what’s important to you, and ways to help you have the best quality of life possible — for as long as possible.

Get support

Learning you have MBC is tough enough. Reading about MBC prognosis can make it even more overwhelming, even if the information helps you in the long-term. You are not alone. We’re here for you every step of the way.

• Get support in person, online, by phone, or in print through our programs and resources.
• Connect with a trained volunteer for emotional support, guidance, and hope on the Breast Cancer Helpline.
• Read personal stories from other diagnosed with MBC.