What is Metastatic Cancer?

Key Takeaways

When a cancer is metastatic, sometimes called stage IV cancer, it has spread from its original location to a distant part of the body. The original tumor is called the primary tumor, while new tumors are called metastatic or secondary tumors.
If breast cancer cells break away and spread to the lung, it is called metastatic breast cancer (and not lung cancer). Metastatic lung cancer refers to a cancer that starts in the lung and spreads to other parts of the body.
Metastatic cancer is diagnosed with blood tests, tumor markers, and imaging studies, including ultrasound, bone scan, CT, MRI, and PET scans. Treatment options include surgery, chemotherapy, radiation, targeted therapy, immunotherapy, and other treatments.

An advanced cancer in which cancer cells break off and spread from where the cancer started to another part of the body is called metastatic cancer. Please continue reading to learn more about metastatic cancers.

What does it mean when a cancer is metastatic?

When a cancer is metastatic, it means the cancer has spread from its original location to a distant part of the body. Cancer metastasis is also sometimes called stage IV cancer. The original tumor is called the primary tumor. The new tumors in other parts of the body are called metastatic or secondary tumors.

When a cancer spreads, the cancer cells resemble the original cancer. They do not look like the cells of the organ to which the cancer spreads. Therefore, metastatic cancers have the same name as the primary cancer.

For example, if a primary cancer develops in the colon, it is called colon cancer. If the colon cancer cells spread to the liver, it will be called metastatic colon cancer (and not liver cancer). The deposits of cancer cells in the liver (that have spread from another part of the body, such as the colon) are called liver metastases.

Similarly, if breast cancer cells break away and spread to the lung, it is called metastatic breast cancer (and not lung cancer). Metastatic lung cancer refers to a cancer that starts in the lung and spreads to other parts of the body.

Sometimes, doctors find distant metastases in other organs but cannot identify where they came from. This means they cannot find the primary cancer. This is called cancer of unknown primary (CUP). Adenocarcinoma is a common form of CUP.

Which cancers can spread?

All cancers can spread. Breast, prostate, lung, colon, pancreatic, kidney, thyroid, bone, and liver cancers commonly metastasize.

Note: Metastatic cancer usually refers to solid tumors, such as breast or prostate cancer, that have spread to other parts of the body. Blood cancers like leukemia, lymphoma, and multiple myeloma may or may not be called metastatic because cancerous cells are found throughout the blood circulation and the bone marrow at the time of diagnosis.

How does primary cancer spread?

A primary tumor can spread by growing directly into surrounding tissues. Cancer cells can also spread to distant organs through the blood vessels. In addition, cancer cells can spread to other organs through the lymphatic system (lymph vessels, nearby lymph nodes, and distant lymph nodes).

What are the symptoms of metastatic cancer?

Metastatic cancer may not cause any symptoms. Or it may cause minimal symptoms, which can be mistaken for other health conditions. When present, the symptoms of metastatic cancer depend on the location to which the cancer has spread. Symptoms at some common sites where cancer spreads are listed below:

Lung metastasis

When metastatic cancer occurs in the lung, the symptoms are often vague and can include cough, chest pain, shortness of breath, and coughing up blood.

Bone metastasis

If a primary tumor spreads to the bone, symptoms can include bone pain, numbness, fracture without injury or with minimal injury, and problems with bowel or bladder control.

Brain metastasis

A primary cancer that has spread to the brain can cause symptoms such as dizziness, headache, problems with vision or speech, difficulty walking, and confusion.

Liver metastasis

Common symptoms of liver metastasis include abdominal pain, ascites (swelling of the abdomen due to fluid collection), nausea, loss of appetite, weight loss, and jaundice (yellowing of the skin and whites of the eyes).

How do doctors make a metastatic cancer diagnosis?

Metastatic cancer is diagnosed with blood tests, tumor markers, and imaging studies, including ultrasound, bone scan, CT, MRI, and PET scans.

What are the options for treating metastatic disease?

Treatment depends on the type of cancer. Most metastatic cancers are treated like the original cancer. This means breast cancer that has spread to the lung is treated like breast cancer. This is because the cancer cells themselves are unchanged; their location has just changed. Treatment options include surgery, chemotherapy, radiation, targeted therapy, immunotherapy, and other treatments.

Sometimes, treating metastatic cancer is guided by symptoms and complications. For example:

If bone metastases are causing pain or there is a risk of fracture, healthcare providers may recommend treatment options such as radiation therapy.
If metastatic tumors in the brain are causing symptoms, doctors may recommend cancer treatments like chemotherapy, radiation therapy, gamma knife surgery, and steroids.
If metastatic cancer cells have caused a buildup of fluid around the lungs with shortness of breath, the treatment plan may include thoracentesis to drain the fluid.
If there are metastases in the liver, cancer treatment may consist of radiofrequency ablation (RFA).

Is metastatic cancer curable?

Metastatic cancers are not curable in most cases. They are advanced cancers that have spread to distant parts of the body. However, people diagnosed with incurable metastatic cancer may be eligible for clinical trials that are investigating new cancer treatments.

Has anyone beat metastatic cancer?

In the past, people with metastatic cancer did not live long. But with newer and better treatments available today, doctors can often treat metastatic cancer, even if they cannot cure it. Complete recovery and cure are not possible for most people even after they have metastatic cancer treated.

How long do you live with metastatic cancer?

How long you live with metastatic cancer depends on the type of cancer and the extent of its spread. Treatments can slow the growth of metastatic cancer, and palliative care can ease many of the symptoms. It's possible to live for many years and have a good quality of life with some types of metastatic cancer.

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