The precise treatment method for metastatic cancer will depend on where the cancer started and where it has spread. As a general rule, primary, localized cancers are treated with surgery or radiation therapy while metastatic cancers are treated with chemotherapy, hormone therapy or another form of systemic therapy. These treatments are usually taken by mouth or injected so they can enter the bloodstream. This allows the medicine to reach cancer cells that have spread throughout the body.

Treatments for metastatic cancer include:

• Chemotherapy. Powerful drug treatment that targets fast-dividing cancer cells and kills them or interferes with their ability to reproduce and spread throughout the body. It is used as a primary therapy in treating metastatic cancers such as lymphomas and germ cell tumors of the ovaries, testicles or uterus. Chemotherapy may be used before or after other treatments, such as surgery or radiation therapy, to prevent the spread of cancer.
  
  
• Hormone therapy. Used to treat certain cancers that depend on hormones to grow and spread. Patients who undergo this treatment sometimes take medications that reduce the levels of certain hormones, such as estrogen (in women) and testosterone (in men). In other cases, patients may take drugs that prevent cancer from receiving the hormones they need to grow. Hormone therapy medications may be used to treat metastatic cancers of the breast, prostate, ovaries or endometrial tissue.
  

  

• Radiation therapy. Uses a specific type of radiation to kill or shrink cancer cells. Radiation targets fast-dividing cancer cells and disrupts or destroys their genetic material, preventing the cells from continuing to grow and spread throughout the body. Radiation therapy is often used to keep primary cancers from metastasizing, or to relieve symptoms once the cancer has spread too far to be cured. Radiation therapy may be provided from an external machine or internally through the use of tiny implanted radioactive "seeds".
  
  
• Biological therapy. Biological therapy drugs are medications that stimulate the body’s immune system to better recognize and attack cancer cells. These medications repair, stimulate or enhance the immune system or, in some cases, target the cancer cells directly.
  
  
• Surgery. In many cases, surgery is not an option for metastatic cancers that have spread too far to be completely removed. However, in some cases, surgery may help patients live longer with fewer symptoms.

The following therapies are most effective in treating various forms of metastatic cancer, according to the American Cancer Society (ACS):