A metastatic cancer, sometimes referred to as advanced cancer, is a cancer that has spread from the initial or primary site to other parts of the body. The spread of the primary cancer occurs when the cancerous cells enter the blood and/or lymph system and travel to other parts of the body where they start to grow and multiply within that new area.
When cancer metastasizes or spreads, it is still referred to as the primary cancer. For example, when lung cancer spreads to the liver, brain or bone, it is still considered lung cancer and not liver, brain or bone cancer.Tumor cells penetrate the endothelial cell lining and the underlining basement membrane to exit the circulation (extravasation). They then grow as a metastatic colony.
Treatment for metastatic cancer largely depends on the location of the primary cancer and the treatment regimen that the patient has already undergone in addition to the location and size of the tumor(s) that have spread to other parts of the body.
As such, treatment for metastatic cancer may include one or more of the following options:
The type of surgery performed to treat the metastatic cancer will depend on the location where the cancer has spread. Surgery is not often used to treat the advanced cancer, but rather is used to stop bleeding, pain, prevent bone fractures and/or relieve other debilitating symptoms caused by the spreading of the cancer.
Radiation therapy is the use of high energy rays to kill the cancerous cells. It can be given externally, meaning the radiation stems from a large machine, or internally, where the radiation is placed directly into the body in the area of the tumor. Radiation is usually given to try to shrink the size of the tumor in order to help alleviate pain associated with the metastasis.
Given intravenously and by pill, chemotherapy works to kill the rapidly dividing cancer cells. Unfortunately, chemotherapy is not selective to killing just the cancer cells, but also depletes other fast-growing cells in the body, which causes several debilitating side effects including hair loss and nausea.
In certain cancers male and female reproductive hormones such as estrogen and androgen fuel the growth and spread of the cancer. Hormone therapies block the activation of these particular hormones to try to stop the growth of the cancer.
Innovative research over the past decade has yielded a better understanding of how certain genes or proteins stimulate the growth of certain cancers. Most targeted therapies typically receive their first indication to treat advanced or metastatic cancers.
In metastatic cancer, it is not unusual for the cancer to spread to the bones. Therapies called bisphosphonates, which are given intravenously, along with calcium and Vitamin D are given to help prevent fractures by strengthening the bone affected by the spread of the breast cancer.