Advanced Prostate Cancer

Immunotherapy

Immunotherapy is a type of treatment that is used to repair or boost the ability of the immune system to fight cancer, infections, and other diseases. The immune system is you body’s defense against harmful organisms or substances such as bacteria, viruses, and cancer cells. Immunotherapy is often combined with other cancer treatments such as ADT and radiation therapy, but it may also be used alone.

Immunotherapy should not be used if you are allergic to the drug, have an autoimmune disease (a condition in which the immune system attacks healthy cells in the body), use medicine that suppresses the immune system (immunosuppressant), or are unable to tolerate the treatment.

Immunotherapy appears to increase survival when used to treat other cancers, including lymphoma, breast cancer, melanoma, and prostate cancer, but further studies are needed to evaluate the effectiveness of immunotherapy for the treatment of advanced prostate cancer. One type of immunotherapy that has been used for the treatment of advanced prostate cancer is cancer vaccines.

Cancer Vaccines

Cancer vaccines, or sometimes called immune therapy, have been studied for years, but progress has been slow and most cancer vaccines are still in experimental stages. Unlike vaccines that target and prevent viruses that cause a disease (such as measles or smallpox), the cancer vaccine stimulates the immune system to attack a disease (cancer) that is already in the body. The vaccine contains cancer cells, parts of cells, or antigens (substances that the body recognizes as foreign), which trigger the immune system to respond. Because prostate cancer is typically a slowly progressing disease, multiple cancer vaccinations may be given over time to boost the immune system and develop a strong anti-tumor response. Studies have also shown that when a cancer vaccine is used after ADT, it may be even more effective. Cancer vaccine is appropriate for men with an intact immune system and a slowly progressing cancer. The immune system needs time to build up after the vaccine is given, and if the cancer is fast-growing the vaccine is unlikely to work.

Active Cellular Immunotherapy

Sipuleucel-T (Provenge) is the first FDA-approved active cellular immunotherapy for some men with advanced prostate cancer. The drug is made using your own immune cells. Some of your blood is collected at a cell collection center, the white blood cells (containing immune cells) are separated, and the rest of the blood is returned to your body. After the cells are exposed to a protein found on prostate cancer cells, they are returned to your body through a vein. This process is repeated two more times, for a total of three doses of treated cells. These treated cells cause other immune system cells in your blood to attack the prostate cancer.

Side Effects

Vaccines don’t harm normal tissue, only tissues perceived as foreign, such as tumors, so there are relatively few side effects. Most of the common side effects for cancer vaccines are mild to moderate in severity and include flu-like symptoms including: fever, chills, fatigue, back and joint pain, nausea and headache. More serious infusion reactions can occur, including shortness of breath, wheezing, dizziness, high blood pressure, and stroke.

Questions about Radiation Therapy You May Want to Ask Your Doctor

• Could I benefit from immunotherapy?
• What are the risks of treatment with a cancer vaccine?
• What are the side effects?
• How is treatment given?
• How many treatments will I need?
• What is the cost of the treatment and does insurance cover it?

Additional Sources of Information

• American Cancer Society: www.cancer.org
    Immunotherapy
• American Society of Clinical Oncology patient Web site: www.cancer.net
    Understanding Immunology
• National Comprehensive Cancer Network: www.nccn.com
    Immunotherapy May Boost Cancer Treatment