In order to understand prostate cancer and immunotherapy treatment, you need to learn a little bit about the progression and standard treatment of prostate cancer.
In the United States, prostate cancer is the second leading cause of cancer death among men with more than 200,000 new cases and more than 27,000 deaths annually. In some men, prostate cancer is diagnosed early with only localized disease, while others are diagnosed late after the disease has spread.
Prostate cancer and immunotherapy–standard therapy
Standard treatment for prostate therapy is hormone therapy or androgen deprivation therapy. The goal is to reduce levels of male hormones, called androgens, in the body, or to prevent them from reaching prostate cancer cells. The main androgen in men is testosterone.
Despite initial response rates in the 80 to 90% range, nearly all men eventually develop progressive disease. Immunotherapy for prostate cancer is indicated when patients develop symptoms and progressive disease following androgen deprivation therapy, also referred to as castration-resistant metastatic prostate cancer.
Prostate cancer and immunotherapy–Provenge therapy
Sipuleucel-T (Provenge) is a relatively new therapy for the treatment of asymptomatic or minimally symptomatic, castration-resistant metastatic prostate cancer. This therapy is like a vaccine that stimulates your own immune system to attack and fight the spread of cancer.
In order to be considered a good candidate for this therapy, you need to have a rising PSA level despite standard treatments. Additionally, the cancer needs to have spread outside of the prostate but not be significant enough to need narcotics for pain control.
Basically, your body’s immune cells are taken out of your body and treated to develop your Provenge infusion. In this sense, your treatment is tailored for you specifically. When your immune cells are given back to you as an infusion, your immune cells have been trained to find and attack the advanced prostate cancer cells in your body. Additionally, the Provenge infusion helps your body to continue to increase its immune response to your cancer.
One of the advantages of this treatment is the relatively smaller number of side effects and tolerability of the treatment.
Prostate cancer and immunotherapy–immune therapy
PROSTVAC is another therapeutic cancer vaccine that is currently in clinical trials. This particular vaccine stimulates an immune response against prostate cancer by targeting the prostate specific antigen or PSA.
GVAX is a genetically modified to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF), an immunostimulant. It is currently being evaluated in a number of different combinations.
Prostate cancer and immunotherapy will continue to be linked in the near future with the development of novel therapies as well as sequencing and combinations of these new drugs.
Read more in our Prostate Cancer Health Center.
References
Fong L, Small EJ. Immunotherapy for prostate cancer. Semin Oncol 2003; 30:649-58.
May KF Jr et al. Prostate cancer immunotherapy. Clin Cancer Res 2011 Aug 15; 17(16):5233-38.
Rini BI, Small EJ. Immunotherapy for prostate cancer. Current Oncology Reports 2001, 3:418–23
