Metastatic carcinoma is cancer that has spread from the original site (the primary tumor) to other parts of the body. Metastasis means the cancer cells travel through blood or lymphatic systems to reach and grow in new places. In some cases, the new cancerous cells may form another tumor in a different part of the body that is still considered a metastatic lesion because the original type of cancer is present. Metastatic breast cancer is an example of this.
Cancer cells can form metastatic tumors in a number of ways. The most common way is to spread from a cancerous organ such as the breast, colon or lungs to a different part of the body through the bloodstream. Another way is for cancer cells to spread from a single location to other locations by growing around and pushing off surrounding healthy tissue to create a new tumor. Cancers can also spread to a new area by breaking apart and travelling through the lymphatic system or the bloodstream to reach another part of the body.
The most common sites for metastatic cancer are the bones, liver and lungs. When cancer spreads to the lungs, it is often called metastasis from the breast and is referred to as stage IV breast cancer. When a cancer spreads to the liver, it is called metastatic liver disease or metastasis from a hepatocellular carcinoma.
A small percentage of people with metastatic cancer have no symptoms or signs, and it is not always easy to determine where the cancer originated. Some cancers, such as melanoma, can spread so quickly that it is impossible to find the original source in time to treat it effectively. In other cases, the source cannot be identified even after the patient dies (as in carcinoma of unknown primary origin).
When the doctor sees a person with metastatic tumors, they will first want to know how long the person has had them and what the original type of cancer was. They will then perform a biopsy, which involves removing a sample of the tumor for laboratory testing. This can be done with a needle or with surgery. In addition, a liquid biopsy may be recommended for some patients, which looks for DNA from the original cancer that is circulating in the bloodstream.
Once doctors know the exact site of the metastatic lesions, they can plan a treatment regimen. Treatment options may include surgery, chemotherapy, radiation therapy or gamma knife surgery. In some situations, these treatments can cure the metastatic tumors and prevent them from spreading to other areas of the body. However, in most cases, the goal is to control the cancer and relieve symptoms, which is usually accomplished by using combination therapies. A second opinion from a physician who is experienced with treating metastatic carcinoma is important to help people make treatment decisions. It is also a good idea to enroll in a clinical trial for people with advanced cancer to learn about the latest treatments for their condition.
