Prostate Cancer Medication: Hormone, Immune Therapy, Chemotherapy
Author: Brian Hildebrandt, Last Updated: March 13, 2017
Prostate cancer medication can be used alone or in conjunction with other treatments, depending on the progression of the disease. They are separated in to the following classes, which is dependent on their method of action.
1. Hormone Therapy (Anti-androgens/Lower Testosterone and DHT (dihydrotestosterone))
- Androgen Antagonists
- Gonadotrophin Releasing Hormone Agonists
- Gonadotrophin Releasing Hormone Antagonists
2. Chemotherapy (Mitotic Inhibitors)
3. Immune Therapy (Immunotherapy)
Prostate Cancer Hormone Therapy (Anti-Androgens)
Lowering testosterone and one of it’s metabolites DHT (dihydrotestosterone), has shown efficacy in both slowing the progression and reducing the number of prostate cancer cells.
Androgens are a suspected contributor to the growth of prostate cancer cells, and by reducing their effects, potential progress can be made during treatment.
Androgen Antagonists
Androgen antagonists block the actions of testosterone and DHT on the receptors of prostate cancer cells. It’s a more direct method of depriving cancer cells of testosterone, which has been known to fuel their growth.
Common testosterone antagonists include; bicalutamide (Casodex), flutamide (Eulexin), and nilutamide (Nilandron).
Gonadotrophin Releasing Hormone Medications
Used mainly for advanced prostate cancer, this class of medication generally cause an initial increase in GnRH (Gonadotrophin Releasing Hormone) from the pituitary, followed by a sharp decrease afterwards.
This effect causes desensitization to GnRH downstream at the hypothalamus, which in turn governs LH (Luteinizing Hormone) and FSH (Follicle Stimulating Hormone).
LH is responsible for signalling the testes to produce testosterone. When this signal is diminished past a therapeutic level the action of these prostate cancer drugs becomes evident.
Examples of GnRH agonists/analogs include; Leuprolide acetate (Lupron, Eligard), Triptorelin (Trelstar Depot), Goserelin acetate (Zoladex), and Histrelin acetate (Vantas).
GnRH Antagonists
GnRH antagonists generally work in the same manner as the agonists. However, rather than relying on desensitization, GnRH antagonists rapidly stops production at the pituitary, which tends to lead to faster decreases in testosterone.
Examples include; Degarelix (Firmagon), Cetrorelix (Cetrotide), Ganirelix (Antagon), and Abarelix (Plenaxis).
Prostate Cancer Chemotherapy (Mitotic Inhibitors)
Chemotherapy is generally used when there is a confirmed or strong possibility the cancer has spread to distant areas of the body. It is also sometimes used in conjunction with other prostate cancer treatments, most notably hormone therapy.
Chemotherapy’s primary action is to prevent cell growth and proliferation, which includes both normal and cancer effected cells. The routes of administration are usually oral and intravenous – in some cases both methods are used.
Examples of chemotherapy drugs include; Docetaxel (Taxotere), Mitoxantrone (Novantrone), Estramustine (Emcyt), Paclitaxel, Cabazitaxel (Jevtana).
Immune Therapy (Immunotherapy)
Immunotherapy’s mechanism of action is to stimulate the patient’s immune system to allow it to better fight off the cancer. They are generally used when there are little to no prostate cancer symptoms present during metastases, and are not responding well to hormone therapy.
Examples of immunotherapy prostate cancer medications include; Sipuleucel-T (Provenge).