Medical therapy uses drugs and other anti-cancer agents to fight cancer. These are also called systemic treatments because they can kill cancer cells throughout your whole-body system. Even high-risk prostate cancer may still be cured if appropriate systemic therapy is incorporated.
Medical therapies may be part of your treatment plan if your prostate cancer:
- is considered high risk
- recurs after initial surgery and/or radiation
- has spread beyond the prostate gland (metastatic disease)
- cannot be treated with surgery or radiation because you have other health issues
Genetic and advanced tumor testing guide your treatment
At Roswell Park, additional testing helps to determine whether you or your tumor has certain genetic characteristics or mutations. These results can help guide your physicians to choose the specific types of drugs most likely to help you. You should have these tests if you have:
- High risk disease, or Gleason score of 8 and above
- A family history of prostate cancer
- Prostate cancer that is already metastatic at the time of diagnosis
- Prostate cancer that continues to grow and spread even after testosterone levels are reduced to very low levels
Hormone therapy for prostate cancer
Prostate cancer cells need male hormones, called androgens, to grow. Testosterone is an androgen that is made by the testes. Lowering the amount of testosterone made by your body and/or blocking the ability of cancer cells to use the testosterone can slow tumor growth or shrink the tumor.
Hormone therapy can lower the testosterone to a level that is similar to having the testes surgically removed, a procedure called castration. Several drugs are available to achieve this effect, and your medical oncologist will carefully select the specific ones best for you and your cancer.
Hormone therapy for prostate cancer includes two different types of drugs, and using both together has improved cure rates and survival.
- Androgen deprivation therapy (ADT) uses various drugs to block the testosterone made by the testes. These include anti-estrogens, and drugs that affect LHRH, a hormone made in the brain that tells the body to make testosterone.
- Androgen receptor pathway inhibitors (ARPIs). These next-generation hormone therapies block testosterone from sources other than the testes, such as the adrenal glands, or the prostate cancer cells themselves.
ARPIs have improved cure rates in patients with localized disease by 5 to 7% and have prolonged survival in patients with advanced disease by 30%.
Additional medical therapies, such as chemotherapy, immunotherapy, targeted therapy, and radiopharmaceuticals are often used along with hormone therapy.
The Roswell Park Advantage
Androgen receptor pathway inhibitors (ARPIs) are a relatively new class of hormone therapy drugs that have made a significant improvement in prostate cancer survival. Several are now FDA approved, and Roswell Park patients had early access to these through clinical trials.
Biomarker targeted therapy for prostate cancer
These therapies may benefit you if your prostate cancer is associated with a genetic mutation, such as BRCA1, BRCA2, ATM, or CHEK2. In up to 15 to 20% of men with advanced prostate cancer, a mutation is found that can be treated with a biomarker targeted therapy.
These drugs, also called PARP inhibitors, work by blocking the PARP protein, which the cancer cells need to repair themselves. When cancer cells cannot fix their own DNA, the cells accumulate too much damage and die.
Analyzing your tumor’s DNA can reveal other genetic abnormalities for which other targeted therapies, including drugs currently in clinical trials, may be useful against your cancer.
Immunotherapy for prostate cancer
Immunotherapy is a type of cancer treatment that uses your body’s immune system to fight against your cancer. Immunotherapy for prostate cancer may involve:
- Checkpoint inhibitors. This type of immunotherapy helps “release the brakes” of your own immune system by targeting a genetic alteration found in some prostate cancers. Pembrolizumab (Keytruda) is now FDA approved for any cancer with a genetic alteration called MMR deficiency. Roswell Park tests all advanced prostate tumors for this genetic mutation. About 3% of prostate cancers will show a sensitivity to checkpoint inhibitors.
- A prostate cancer vaccine. Sipuleucel-T (Provenge), was the first FDA-approved therapeutic cancer vaccine. This treatment uses your own immune cells that have been reengineered to recognize and kill prostate cancer cells. Sipuleucel-T (Provenge) is given intravenously (through an IV). Use of this option has declined as other therapies have become available.
Radiopharmaceuticals for prostate cancer
Radiopharmaceuticals are drugs that carry a radioactive substance or isotope. This is a growing and promising area of therapeutics in prostate cancer and will likely change prostate cancer treatment over the next decade.
Radiopharmaceuticals, also called radioligand therapy, find and latch onto cancer cells by homing in on a specific protein, receptor or other biomarker, similar to how targeted therapy drugs work. Once the drug finds the targeted cells, the radiation it carries begins to kill the targeted cells.
Currently there are two FDA-approved radiopharmaceuticals for the treatment of prostate cancer:
- Pluvicto™ (lutetium Lu 177 vipivotide tetraxetan) is a radiopharmaceutical that targets prostate cancer cells that have a biomarker called prostate-specific membrane antigen (PMSA). Cells that are PSMA-positive absorb the drug which releases radiation to damage and kill them. Your physician team will determine whether your prostate cancer cells are PSMA-positive with a specialized PSMA-PET scan. Pluvicto is delivered through an intravenous infusion, every six weeks for a maximum of six treatments.
Pluvicto is considered a theranostic treatment, a rapidly growing approach to cancer treatment. - Xofigo (radium Ra 223 dichloride) is an injection used to treat prostate cancer that no longer responds to hormone therapy alone. This drug targets the bone and releases radiation there, killing the cancer cells in the bone. This treatment is used in patients whose prostate cancer has spread to the bone but not to other parts of the body. The injection is given every 4 weeks for a maximum of 6 doses.
Theranostics — a new frontier in prostate cancer treatment
This promising approach — using new radiopharmaceuticals to deliver radiation directly to the cancer cell — is a rapidly growing field called Theranostics. Roswell Park is at the forefront of this work and has offered Theranostic treatments to patients for years. In addition to Pluvicto, a number of other radiopharmaceuticals that act on other prostate-specific proteins are in development.
Chemotherapy for prostate cancer
Chemotherapy is an option for patients with metastatic prostate cancer, where the cancer has spread to the lymph nodes and bones. Tumor testing at diagnosis can also indicate whether you may benefit from having chemotherapy earlier.
Chemotherapy may be added to your hormone treatment to help control further spread of the cancer. While chemotherapy is not expected to destroy all the cancer cells, it may shrink the cancer or slow its growth and reduce pain.
Chemotherapy uses drugs that are injected or infused through a vein to kill cancer cells. Unfortunately, these drugs also damage some normal cells. The chemotherapy dose must be high enough to kill the cancer cells but not high enough to destroy too many healthy cells. Your physician team will adjust your chemotherapy to maximize effectiveness and minimize toxicity.