A number of tests are used to diagnose breast cancer that has spread outside the breast area to other parts of the body.
Test results will be summarised in a pathology report and in imaging reports. The treating doctor can explain what the test results mean and whether other tests will be needed in future. Some women find it helpful to keep a copy of their reports so that they can refer to them later.
The words used in the pathology report to describe breast cancer that has spread outside the breast area will depend on the parts of the body affected.
- Locally advanced breast cancer is breast cancer that has spread to areas near the breast. The stages used to describe locally advanced breast cancer are Stage IIB (>5cm) and Stage III.
- Metastatic breast cancer (also called advanced breast cancer) is breast cancer that has spread to other parts of the body. The stage used to describe metastatic or advanced breast cancer is Stage IV.
Tests if breast cancer has spread
A number of different tests may be used to look for cancer in different parts of the body.
These tests will only be done if a woman has symptoms which suggest that cancer has spread outside the breast.
Tests may include:
X-rays are used to look for changes in the bones or chest that may be due to cancer. X-rays are quick and easy to do but may not show early signs of cancer.
During a bone scan, a small amount of radioactive substance (called a radiopharmaceutical or radionuclide) is injected into a vein, usually the arm. The radionuclide travels around the body in the bloodstream to the bones. The radionuclide will need to concentrate in the bones before scanning can start. This may take 1–3 hours.
During the scan, the woman lies still on a scanning table while a scanner moves over her and produces pictures of her bones. The scan can take up to 1 hour.
A bone scan can pick up small areas in the bones where cells are growing more quickly. These are called ‘hot spots’. Hot spots may be due to cancer or another medical condition, such as arthritis, infection or an injury. Other tests may be used to confirm the diagnosis.
A bone scan to detect metastatic breast cancer is different from a bone density study, which assesses the risk of osteoporosis.
Blood tests can be used to check for different things, including how well the liver is working, how healthy the bone marrow is and whether there are higher than normal levels of calcium in the blood. High levels of calcium can be a sign of metastatic breast cancer.
An ultrasound may be used to look for changes in the liver and elsewhere in the body. This only takes a few minutes and is painless. Fasting for at least 4 hours is usually required before an ultrasound of the abdomen.
A CT or CAT scan may be used to look for cancer in different parts of the body. The test takes about 10–20 minutes.
During a CT scan, the woman lies on her back on a moving table, which passes through a doughnut-shaped machine that takes pictures of the inside of her body. The scan is painless.
Some people feel claustrophobic inside the scanner, although this is less common than with MRI scans. It’s possible to have a sedative while the scan is being done.
Sometimes a small amount of dye is injected through a vein in the arm or hand before the scan. This makes it easier to see changes in the body that may be due to cancer. Some women are asked to drink an oral contrast before the scan. This makes it easier to tell the difference between the bowel and other organs nearby.
An MRI scan may be used to check for signs of cancer in the brain, spinal cord or spine. It may also be used to look for cancer in the liver. The test takes about 30 minutes and is painless.
During an MRI scan, the woman lies inside a tunnel-like machine while it takes pictures of the inside of her body.
Some people feel claustrophobic inside the machine. It’s possible to have a sedative while the scan is being done. The machine can also be noisy. Listening to music during the scan or having a friend or family member in the room can be helpful.
Sometimes a small amount of contrast agent is injected through a vein in the arm or hand during the scan. This contrast makes it easier to see changes in the body that may be due to cancer.
Occasionally, a PET scan may be recommended to look for cancer in the body. The scan can show any areas in the body where cells are more active than usual (for example, fast-growing cancer cells). The scan is painless and may take between 15 minutes and 2 hours.
Before the scan, a small amount of a radioactive material is injected into a vein, usually in the arm. The woman then lies on her back on the scanning table. The table moves through a scanner ‘ring’, which takes pictures of the inside of the body.
PET scans are available in only a few centres in Australia as they require expensive specialised equipment. A combined PET and CAT scan test is available in some centres.
If a chest X-ray shows fluid around the lungs, doctors may drain (aspirate) the fluid to look for changes that may be due to cancer.
A local anaesthetic is given before the fluid is drained. A small needle is then inserted between the ribs into the space around the lungs. Fluid is drained and sent for examination by a pathologist.
A bone biopsy is not a common test for metastatic breast cancer. It may be done to check whether one abnormal area found on a bone scan is due to cancer.
A local anaesthetic is given before the biopsy to reduce the pain. A needle is then inserted into the bone and a sample of bone is removed for examination by a pathologist. The biopsy can be uncomfortable and the area may be sore for a few days afterwards.
A biopsy of the primary cancer in the breast will usually only be done if metastatic breast cancer is the first diagnosis of cancer. The breast biopsy is done to confirm the diagnosis and find out what receptors are on the breast cancer cells. This information will help doctors work out which treatments are best.
If a woman has been diagnosed with breast cancer before, her doctor can look in her records to find out what receptors are on the breast cancer cells. A repeat biopsy may be done to test for changes in receptors since the original cancer was found.
Waiting for test results
It can sometimes be difficult at first to tell whether symptoms are due to cancer or other medical conditions. Waiting for test results can be a worrying time.
Some women worry about the time it takes to diagnose their metastatic breast cancer. However, current evidence suggests that being diagnosed with metastatic breast cancer a few weeks or months after the first symptoms develop will not make a difference to the length or quality of a woman’s life or how she responds to treatment.
For more information about radiology tests visit the Royal Australian and NZ College of Radiology website.