Sometimes cancer cells spread to other parts of the body. When this happens, the breast cancer may be described in a few different ways: metastatic, advanced, or stage IV. The term "metastases" refers to specific areas of spread, such as bone metastases.
If you have signs or symptoms of metastases, your doctor will likely use local treatment (treatment directly to the cancer area) to relieve the symptoms and to control the disease at that spot. Radiation can shrink and help control specific spots where the cancer has spread. Radiation can help:
- decrease pain
- lower the risk of broken bones in areas that may be weakened from cancer
- decrease bleeding
- improve breathing by opening up a blocked airway
- take pressure off a pinched nerve that might be causing pain, numbness, or weakness
The radiation dose and schedule for metastases depends on a number of factors, including:
- the urgency of the situation (pain, loss of function, size and location of the metastasis, for example)
- any previous radiation you may have had
- the schedule for any other treatments
The most common doses prescribed are 3,000 centiGrays over 2 weeks or about 3,750-4,000 centiGrays over 3 weeks.
Here are some of the most common "hot spots" of metastatic breast cancer that can be treated with radiation:
Spinal cord compression means the cancer is putting pressure on, or squeezing, your spinal cord, the large bundle of nerves in the middle of your backbone that connects the brain to the body. Cancer growing in the backbone can put pressure on the spinal cord. This pressure can damage the nerves, resulting in back pain, weakness, and even paralysis, as well as changed bowel and bladder habits.
Radiation is given to the problem spot to kill the cancer cells, usually after steroids have calmed the swelling. Occasionally, you may need surgery to reduce pressure around the spinal cord.
Brain metastases require immediate treatment, especially if they are causing symptoms such as headaches, nausea, numbness, vision changes, or, in rare cases, seizures. Your doctor will prescribe steroids first, followed by other treatments, such as surgery, chemotherapy, and/or radiation.
Radiation is aimed at the whole brain or specific nerves. It is rarely aimed at the entire spinal cord. Radiation to too large an area would lower the number of important infection-fighting cells, which can delay other treatments.
Bleeding problems can be helped by radiation. Sometimes a cancer growing into the skin on or near the breast can cause bleeding, as can a tumor in an air passageway to the lung. Bleeding usually responds quickly to radiation.
Cancer in the bones of the legs, hips, or arms can weaken and destroy their structure and strength. This makes these bones more likely to break, even without a fall or other injury.
Radiation directed at the cancer will destroy the cancer cells so the bone can heal (bone cannot rebuild and strengthen itself if cancer cells are in the way). Additionally, if a bone in the arm or leg is seriously weakened, a surgeon may place a metal rod in the weak area to strengthen the bone.
A special kind of radiation can be given to people who develop scattered, painful bone tumors that don't respond to chemotherapy. These tumors can't be easily treated with localized radiation because the area needing treatment is too big. The radioactive chemical strontium-89 can be given intravenously (injected into one of your veins) as a one-time dose. The bone-making cells and the cancer cells in the bone take up the radiation given off by these chemicals. The treatment generally reduces pain, but it can make you more prone to infection, anemia, and bleeding problems.
Liver pain is caused by the tumor growing inside the liver and stretching the surface of the liver. This pain is best treated with chemotherapy and managed with pain medications. But if no chemotherapy or pain medication seems to be working, radiation to the liver can be useful for reducing pain.
Radiation sometimes may make symptoms worse before they get better. That's because cancer doesn't like to be radiated — it can swell a little before it starts to shrink. The swelling can put extra pressure on sensitive nerves. Pain medication, and sometimes a short course of steroids, can help relieve these temporary symptoms. Diagnostic tests after treatment is over will eventually show how much the cancer has been reduced by the radiation.