Metastatic breast cancer: Statistics, diagnosis, treatment & survival
Metastatic breast cancer (sometimes abbreviated MBC) occurs when breast cancer spreads to other parts of the body. Metastatic breast cancer is also called advanced breast cancer or Stage IV breast cancer.
In this guide, you will:
Learn important information for patients and their loved ones about metastatic breast cancer, including statistics, risk factors, prognosis, survival, and how it's diagnosed and treated.
Get to know the stories and feelings from real patients with metastatic breast cancer.
This content should not be used as a substitute for professional medical advice, diagnosis, or treatment. As always, consult with your doctor before trying any new treatments or medications.
What is metastatic breast cancer?
Metastatic breast cancer occurs when breast cancer spreads to other areas of the body. Breast cancer begins in breast tissue (called the primary cancer or local cancer). Sometimes breast cancer remains undetected until it spreads to other parts of the body (a process called metastasis). The other parts of the body to which the breast cancer has spread are called metastases (also called secondary sites). When cancer that began in the breasts spreads to other organs, it's still considered breast cancer. For example, breast cancer that spreads to the bones would be called "metastatic breast cancer of the bones" or "bone metastases."
About 6% of women with breast cancer may already have metastases at the time of their initial breast cancer diagnosis. In other words, by the time these women learn that they have breast cancer, it has already spread to other parts of the body. Among women with an initial primary breast cancer diagnosis, 12 to 30% will eventually develop metastatic breast cancer, according to current estimates.
Risk factors for metastasis in breast cancer patients include:
larger primary tumors
older age (over 50 years old)
triple-negative or HER2+ breast cancer types
higher clinical stage of existing tumors
Metastatic breast cancer is often aggressive (meaning that it spreads faster). According to a 2022 analysis, the median breast cancer-specific survival rate from the time of initial diagnosis of metastatic breast cancer was 28 months. However, the predicted outcome and survival time of patients with metastatic breast cancer depends on the following factors:
the patient's age at diagnosis
the hormonal status of breast cancer tumors (estrogen receptor-positive or negative, progesterone receptor-positive or negative, and HER2-positive or negative)
the presence of BRCA1 or BRCA2 genetic mutations
whether breast cancer was diagnosed before or after metastasis occurred
the site of metastasis (in other words, the location to which the breast cancer spreads in the body)
Evidence also suggests that metastatic breast cancer survival rates are increasing each decade due to better detection methods and new treatment options.
An acquired mutation known as the ESR1 mutation may play a role in breast cancer metastasis.
Where can breast cancer spread?
The most common areas to which breast cancer spreads are the lymph nodes, bones, lungs or pleura (tissues encasing the lungs), skin, liver, and brain or central nervous system. Less commonly, metastatic breast cancer can also spread to the gastrointestinal tract, reproductive system, endocrine glands, or other organs.
Metastasis is a complex process that involves cells dividing from the original tumor, spreading to other areas, evading the immune system, and changing the environment of other tissues in ways that favor growth of cancer cells.
How is metastatic breast cancer diagnosed?
Doctors detect and diagnose metastases using techniques including manual examination, imaging (mammography and other X-rays, ultrasound, MRI, PET, and CT scans), tissue biopsies, and blood tests. Metastatic breast cancer is sometimes diagnosed at the time of the initial breast cancer diagnosis, or it may be detected months or years later.
If you've recently been diagnosed with breast cancer, your doctor may assess you for metastases (spreading) using a chest X-ray and blood tests. As time goes on, your medical team will also use the appropriate imaging techniques to monitor for potential spreading of cancer, depending on your risk factors.
What are treatments for metastatic breast cancer?
The main goals of breast cancer treatment are to eliminate local tumors in the breasts, prevent their recurrence, and to reduce the risk of metastasis (spreading). While surgery can be effective for non-metastatic breast cancer, in some patients with metastases, it may worsen spreading. Recently, new treatments have improved survival.
Whole-body treatments (also called systemic) for metastatic breast cancer are treatments that can target multiple potential sites of cancer in the body at the same time. Depending on the type and location of breast cancer, the patient's medical history, and other individual factors, a combination of systemic treatments may also be used.
Newer systemic therapies include:
targeted therapies that interfere with the growth and spread of certain types of cancer
immunotherapy, which helps your immune system fight cancer cells
selective estrogen receptor degraders (SERDs), which are drugs that bind to the estrogen receptor and down-regulate it or decrease its activity
Older therapy options such as chemotherapy, radiation, and hormonal therapies including selective estrogen receptors and aromatase inhibitors are also used for some types of metastatic breast cancer, and may be combined with newer systemic therapies.
Estrogen receptor 1 (ESR1) gene mutations can be present in some types of estrogen receptor positive (ER+) advanced breast cancer. While these gene mutations can be hereditary, patients can also acquire ESR1 gene mutations after undergoing certain breast cancer treatments.
How to cope with metastatic breast cancer: Patient stories
There is currently no cure for metastatic breast cancer. It is terminal, but treatments can prolong survival and improve quality of life for patients:
"My sister, 62 years, passed away after a 4 1/2 year battle with stage 4 breast cancer. Since her cancer diagnosis, she lived life to her fullest, finding joy in all that she could. She kept a positive attitude even during the last 8 months where life was not easy for her. Her first 3 years on [medication] were good and if you didn’t know her, you wouldn’t have known she was ill. The last year was rough with one medical issue after another but she took it as she did everything in life; with positivity and courage. A few months ago, she had to start IV chemotherapy. Her body was tired and her liver just couldn’t handle it any longer. I‘m so thankful she was able to enjoy welcoming her grandson into her life 10 months ago. She lit up whenever he was near or simply by talking about him or sharing stories or pictures. Lisa brought so much joy to my life. She will be sorely missed." Go to post
Metastatic breast cancer treatment sometimes involves trying different treatment options while monitoring the results:
"My mother is starting her second fight with breast cancer after a stage two about 11 years ago. She has a growth in the lungs that is some cause for concern and had a spinal surgery to remove a growth a few weeks ago. After a second opinion from a medical oncologist in the family (on the other side of the country), we're trying [medication] while doing radiation to the spine for another growth that is cause for concern and to clean up around where the surgery took place. We have been informed that we are in a bit of a data-free zone when it comes to taking [medication] along with a radiation treatment but wanted to see if anyone has any experience with these two couple together at the same time and potential worsening of side effects. We are praying for good results but if things are not looking great clinically after the radiation treatment, we're most likely looking at shifting to [medication]." Go to post
Patients with metastatic breast cancer often deal with pain, fatigue, and other issues:
"Diagnosed with de novo metastatic breast cancer 2 years ago. After 2 years with negligible side effects, I am now experiencing severe hip pain, which was thought to be bursitis, but I have my doubts, as it’s been going on for 4 months. Scan showed no progression into hips thank goodness. Now I’m wondering whether it’s a side effect from [medication]? Seems unusual this would happen 2 years in? Anybody?" Go to post
"It’s funny, every ache and pain now, we assume it’s our cancer… I’m 73, so my body is in the 'growing old stage'...things hurt one day, then the next day it’s gone...yet, the first thing pops into my head, 'now where is the cancer going'." Go to post
"Bursitis is painful and can take a while to heal. A massage could be a good idea! And a physical therapist would be another option and they can soon tell you if it’s definitely bursitis....But it could easily be a side effect of [medication] too and you wouldn’t be the first to report it. I have had bursitis too and the pain is much worse than arthritic changes or bone metastases in the hip. It approaches the pain level of a pathological fracture (untreated). I take pain medication so I don’t really feel much pain except as I approach the time to take another tablet. Hopefully all your efforts will resolve the pain, one way or another." Go to post
"I still feel like a doddery old lady on most mornings until I get going (and sometimes all day). Fatigue and aches for me, too. I TRY not to worry, though I do, but the pain can ALSO be from the bones reacting to the cancer being gone (healing up), the side effects of the meds (the pamphlet from the company lists this)." Go to post
"I was a walking pile of joint pain while I was on an aromatase inhibitor for 6 1/2 years, not all happening at once, new pains and aches would just start up whenever they felt like it. My doc never suggested anything to help with that specifically like joint supplements or anything, but when it got really bad and I was having a hard time walking up steps she sent me to a physiatrist who found knots in some of my muscles, mostly in my butt, and she worked those out, I was 99 percent better after that. She said the knots were probably from me tensing up because of the joint pain. Made sense to me and it really helped." Go to post
"I am fairly new to the MBC world so there’s still lots I experience which I am not sure is to be expected. I started treatment last year, 11 years after my initial diagnosis. Just the last month or so I find myself tired, achy and just lacking desire to get moving, and my once full lashes and brows are no more and my hair is terrible....I just feel like I aged so much in the last 3 months." Go to post
Some patients credit their successful, ongoing treatment of metastatic breast cancer to maintaining a positive attitude:
"We really need to almost pretend that we aren't sick and do what we can, laugh when we can and have a positive outlook. Not always easy when we're physically hurting though. I love to watch old comedy movies when I'm really tired, which definitely helps bring up my spirits." Go to post
"Good for you. I am a year triple negative survivor. I too said from the start I was going to beat my cancer. I am now on the natural route too. I take many vitamins to keep cancer away as well as exercising and eating better along with yoga and meditation. The only thing that recently freaked me out is that our risk of it recurrence is higher since there are no hormones to block. I also had a lumpecotmy and 3 lymph nodes involved. Keep on staying cancer free — attitude is 99.5 percent of it." Go to post
"I’m trying very hard not to let this 's---' control my life. I keep very busy every day and try to laugh as much as possible. Our heads have a lot to do with our disease and how fast it takes over… I’ve always been a positive person, an optimist, so I’m hoping this helps." Go to post
Healthy lifestyle changes and stress management are also helpful:
"Early detection is key but also stress, diet, and lifestyle can play a huge part in triple negative. Exercise is important with a cancer diagnosis. Stress was a problem for me and still is, so I do Tai-Chi and some meditation. Also look into visualization. I did this throughout my cancer diagnosis and I personally feel that it does help. You are a great inspiration to us all. Keep up the strength and hopefully in our lifetime we will see a cure." Go to post
Sources
Disclaimer
Member comments have been lightly edited for length and clarity. This content is for general informational purposes only and does not necessarily reflect the views and opinions of any organization or individual. The content should not be used as a substitute for professional medical advice, diagnosis, or treatment. Please consult your healthcare provider about any questions you may have regarding a medical condition.
