Back pain isn’t one of the hallmark symptoms of breast cancer. It’s more common to have symptoms like a lump in your breast, a change in the skin over your breast, or a change in your nipple. Yet pain anywhere, including in your back, can be a sign of breast cancer that has spread. This is called metastatic breast cancer.
When cancer spreads, it can get into the bones and weaken them. Pain in your back could be a sign that a bone in your spine has fractured or that the tumor is pressing on your spinal cord.
It’s important to remember that back pain is a very common condition. It’s much more commonly caused by conditions like muscle strains, arthritis, or disk problems. If the pain is severe and you have other breast cancer symptoms or a history of breast cancer, see your doctor to have it checked out.
When doctors diagnose breast cancer, they assign it a stage. That stage is based on whether the cancer has spread and, if so, how far it has spread. Cancer stages are numbered 1 through 4. Stage 4 breast cancer is metastatic. That means it has spread to other parts of the body, like the lungs, bones, liver, or brain.
Breast cancer can spread in a couple of different ways:
- cancer cells from your breast can move into nearby tissues
- cancer cells travel through your lymph vessels or blood vessels to distant sites in your body
When breast cancer spreads to other organs, it’s still called breast cancer. Symptoms of metastatic breast cancer depend on which organs it has invaded. Back pain can be a sign that the cancer has spread to your bones.
Other symptoms of metastatic breast cancer include:
- headaches, vision problems, seizures, nausea, or vomiting if it has spread to the brain
- yellow skin and eyes, abdominal pain, nausea and vomiting, and appetite loss if it has spread to the liver
- chronic cough, chest pain, and trouble breathing if it has spread to the lungs
Metastatic breast cancer can also cause these, more general symptoms:
- weight loss
- appetite loss
If you have symptoms like a breast lump, pain, nipple discharge, or a change in the shape or look of a breast, your doctor may do some or all of the following tests to see if you have breast cancer:
- Mammogram uses X-rays to take pictures of the breast. This screening test can show whether you have a tumor inside your breast.
- Ultrasound uses sound waves to create a picture of your breast. It can help your doctor tell whether a growth in your breast is solid, like a tumor, or filled with liquid, like a cyst.
- Magnetic resonance imaging (MRI) uses a powerful magnet and radio waves to create detailed pictures of your breast. These pictures can help your doctor identify any tumors.
- Biopsy removes a sample of tissue from your breast. The cells are tested in a lab to see if they are cancer.
If your doctor suspects that your cancer has spread, you’ll have one or more of these tests to see where it is in your body:
- blood test to see if the cancer has spread to your liver or bones
- bone scan to see if the cancer is in your bones
- ultrasound to find out if the cancer has spread to your liver
- X-rays or computed tomography (CT) scan to find out if the cancer is in your chest or abdomen
Your treatment will depend on where the cancer has spread and what type of breast cancer you have. Treatments can include:
Hormone therapy drugs
These medicines are used to treat hormone receptor-positive breast cancers. They work by depriving tumors of the hormone estrogen, which they need to grow. Hormone therapy drugs include:
- aromatase inhibitors (AIs) such as anastrozole (Arimidex) and letrozole (Femara)
- selective estrogen receptor down regulators (SERDs) like fulvestrant (Faslodex)
- selective estrogen receptor modulators (SERMs) like tamoxifen (Nolvadex) and toremifene
HER2-positive breast cancer cells have large amounts of a protein called HER2 on their surface. This protein helps them grow. Anti-HER2 drugs like trastuzumab (Herceptin) and pertuzumab (Perjeta) slow or stop the growth of these cancer cells.
Chemotherapy slows the growth of cancer cells throughout your body. You’ll usually get these drugs in cycles of 21 or 28 days.
Radiation destroys cancer cells or slows their growth. Your doctor might give you radiation if body-wide treatments like chemotherapy and anti-HER2 therapy haven’t worked on your cancer.
Your doctor can treat breast cancer that has spread to your bones with drugs like bisphosphonates or denosumab (Prolia). These medicines slow bone damage and prevent the fractures that can cause pain. These drugs are administered through a vein or as an injection.
To help you manage pain, your doctor might suggest one or more of these drugs:
- Over-the-counter pain relievers such as acetaminophen (Tylenol), aspirin, ibuprofen (Motrin, Advil), or naproxen (Aleve). These drugs help with mild pain.
- Opioid drugs like morphine (MS Contin), codeine, oxycodone (Roxicodone, Oxaydo), and hydrocodone (Tussigon) can help with more severe pain. However, they can become addictive.
- Steroid drugs like prednisone can help with pain caused by swelling.
You can also try nondrug pain relief methods, such as breathing techniques, heat or cold, and distraction.
If your back pain isn’t caused by cancer, treatments such as massage therapy, physical therapy, and stretching may help relieve pain.
Back pain may be a symptom of metastatic breast cancer in some cases. Metastatic breast cancer isn’t curable, but you can manage it. You can slow the progress of your cancer with treatments like hormone therapy, chemotherapy, and radiation. These treatments can prolong your life and improve your quality of life.
You also can enroll in a clinical trial. These studies test new treatments that aren’t yet available to the public. Ask your doctor how to find a trial that matches your cancer type.