When prostate cancer is localized and confined to the prostate it can be cured. This can be done with either surgery or radiation. Once it has spread outside of the prostate it is unlikely that it can be cured. This is where medications come in.
Let’s look into this further. But before we do, remember that prostate cancer (even aggressive prostate cancer) grows slowly.
Prostate cancer that has spread can be controlled. Twenty years ago there was only one way of controlling it and that was with hormonal therapy. Now there are multiple ways of controlling metastatic prostate cancer. There has been an explosion in research and a number of new treatments are now available. We will do our best to make some sense out of the multiple therapies available, but remember to always ask your doctor.
The main categories of medical therapy for prostate cancer are:
- Hormonal therapy
- Chemotherapy
- Immunotherapy
- Genomic targeted therapy
- Targeted drug therapy
In general, prostate cancer needs testosterone in order to grow. Dr. Charles Huggins discovered that decreasing the testosterone levels causes prostate cancer cells to die. This was worthy of a nobel prize, which he was awarded in 1966.
There are multiple medications that are used to block the hormones. Some prevent your body from producing testosterone. Some prevent the testosterone from working by blocking receptors. One of the newer medications prevents your adrenal glands from making tiny bits of testosterone. We’ll detail the many options for medicinal therapies for prostate cancer below.
Hormone therapy
Hormonal therapy is effectively decreasing the testosterone level in the body (to castrate levels) which leads to shrinking prostate cancer. This usually works for a period of time, anywhere from a few months to 10 years or more, until the prostate cancer discovers a way around the hormonal therapy.
Prostate cancer that responds to hormonal therapy is called HSPC – or hormonal sensitive prostate cancer.
Prostate cancer that no longer responds to hormonal therapy is called CRPC – or castrate resistant prostate cancer.
Used for patients who have:
- Late-stage cancer (Cancer has spread far beyond the prostate.)
- High-grade tumors (Cancer cells look very different from normal cells. And they tend to grow quickly.)
- Gleason score ≥ 8 (How the biopsied cells look under the microscope. Scores range from 6 to 10. Low is better than high.)
Or if
- You cannot have surgery or radiation.
- Your cancer is at a high risk of returning after radiation.
- You are going to have surgery or radiation, and shrinking the tumor beforehand would increase the chance for successful treatment.
- Your PSA level remains high or rises even after treatment.
Different types of hormone therapy exist; they stop the production of androgens, such as testosterone, or alter it. Hormone therapy disrupts the ability of androgens to help prostate cancer cells survive and grow. Tumors eventually develop resistance to hormone therapy, so hormone therapy is a treatment, not a cure.
If your cancer has spread beyond your prostate and the surrounding area, you get systemic therapies like hormones (androgens) or possibly chemotherapy. As long as your cancer responds to hormone therapy, it is called castrate-sensitive disease. However, if it becomes less responsive and starts growing again, it is called castrate-resistant disease. That’s because your level or androgen is low, but the cancer still grows. You can still be treated with a number of therapies in this case, and you may be eligible for a clinical trial.
Two types of hormone therapy
Antiandrogens: Oral medication that blocks testosterone and other androgens from interacting with the cancer cell; it is often used in combination with androgen synthesis inhibitors.
Androgen synthesis inhibitors: an injection or pellet implanted under the skin; reduce levels of testosterone and other androgens your body produces.
Side effects
- Impotence
- Loss of sex drive
- Hot flashes
- Growth of breast tissue; tenderness in breasts
- Loss of muscle mass, weakness
- Decreased bone mass
- Shrunken testicles
- Depression
- Brain fog
- Anemia
- Weight gain
- Fatigue
- Increase in cholesterol
- Increase in risk of heart attack, diabetes, high blood pressure
Tell your doctor if you have any of these side effects. Many can be treated.
Hormone therapy for prostate cancer is also known as androgen deprivation therapy. It may involve medication or surgery to remove the testicles (orchiectomy). Prosthetic testicles are available. This surgery usually eliminates the need for further hormone therapy.
Sometimes doctors recommend intermittent dosing to lessen the risk of these side-effects.
Chemotherapy
Chemotherapy is not a standard treatment for early prostate cancer (with some rare exceptions).
It is used if:
- Your cancer has spread.
- Hormone therapy isn’t working.
- You have advanced prostate cancer and carry the AR-V7 gene variant.
- You have had surgery and a short course of chemo may improve the outcome.
When it is used, it is sometimes used with hormone therapy. Chemo is unlikely to cure prostate cancer though.
Chemo drugs attack cells that are dividing quickly, which is what cancer cells do. But other cells do, too, such as blood cells in the bone marrow, the lining of the mouth and intestines, and hair follicles.
You receive chemo intravenously or sometimes orally. If intravenously, you have a port of PICC line inserted for the infusion.
You receive chemo in cycles: a cycle is two or three weeks long. A few days of infusion alternate with many days of rest to give your body time to recover from the effects of the drug. Your doctor looks at how well the treatment is working and adjusts the length of time for you to receive treatment accordingly.
Side effects
- Hair loss
- Mouth sores
- Loss of appetite
- Nausea and vomiting
- Diarrhea
- Increased chance of infections (if you have too few white blood cells)
- Bruising or bleeding (if you have too few platelets)
- Fatigue (if you have too few red blood cells
Additional side effects are associated with certain chemo drugs:
- Allergic reactions to docetaxel and cabazitaxel; medication to help combat this reaction is given before each chemo treatment.
- Leukemia several years later with mitoxantrone (rare)
- Increased risk of blood clots with estramustine
Tell your care team if you experience any of these side effects. Your dose may need changing or your treatment may need to be delayed or stopped.
Immunotherapy
Immunotherapy is a type of biological therapy. Biological therapies work two ways:
- They get the immune system to attack cancer cells: for example, you get an injection of immune system stimulators; another example is that a sample of your immune system cells could be trained to attack cancer cells, then put back into your body.
This therapy does not reduce PSA levels or stop cancer growth, but it may increase survival. It is used for patients with metastatic castration-resistant cancer with few or no symptoms.
- Immunotherapy makes cancer cells easier for your immune system to recognize. There is a prostate cancer vaccine (Sipulecel-T) where immune cells are taken out of your body and exposed to prostate cancer cells, then replaced into the circulation. The theory is that these activated cells will then attack prostate cancer cells.
There are over a dozen types of biological therapies. But prostate cancer is stubbornly resistant to immunotherapy.
Side effects:
- Fever
- Fatigue
- Chills
- Back and joint pain
- Headache
- Nausea
These side effects are often associated with the infusion period and usually resolve in a few days.
Genomic targeted therapy
Genomic targeted therapy is appropriate for men with:
- Metastasized, castrate-resistant prostate cancer
- A specific genetic mutation that keeps cells from repairing damage to DNA
This mutation must be to your BRCA1 and BRCA2 genes. You may have heard of these genes in connection with breast and ovarian cancer. Research suggests that as many as 25% of men with prostate cancer may have these mutations.
When cells become damaged by cancer (and other causes) a protein called PARP (and other proteins) comes to the rescue by helping repair the damage to the DNA.
But people with the genetic mutation to their BRCA1 and BRCA2 genes do not have this repair ability. Researchers reasoned that if they could block the effectiveness of PARP, they would damage the cancer cells, which are also trying to repair their own DNA. After decades of work, researchers have developed PARP inhibitors that block the effectiveness of the PARP protein. PARP inhibitors do not seem to affect noncancerous cells.
It is at this stage in the process when the piling on starts to stop, and your genetic deficit enables it. To recap, you have cancer, it has spread, and you don’t even have the genes that help repair damage to DNA. But we now have PARP inhibitors. When they deprive cancer cells of their ability to repair themselves, the cancer cells die.
You take PARP inhibitors as pills.
Side effects
- Anemia
- Severe drops in white blood cell count
- Nausea
- Vomiting
- Risk of myelodysplastic syndrome (affects formation of blood cells in the bone marrow)
Take matters into your own hands
During genomic targeted therapy, and any treatment for cancer, work to manage your side effects.
- Rest. Your cancer is being attacked by powerful drugs. Your body is affected. Learn how to relieve the stress caused by the side effects by doing things you enjoy. Try listening to music, doing yoga or stretching, walking, watching TV.
- Keep a journal of changes to your body and emotions. This list will help you speak thoroughly and specifically when you see your doctor. And it will help your health care team help you manage your side effects.
- Tell your providers and health care team about all side effects. Many are manageable with medication.
- Expect to have unexpected reactions to the drugs.
- List all your medications and ask your doctor what to look for as a result of taking each one.
- Tell your healthcare team promptly if you experience fever or nausea. Don’t wait until your next appointment.
Prostate cancer that has spread can be controlled. Twenty years ago there was only one way of controlling it and that was with hormonal therapy. Now there are multiple ways of controlling metastatic prostate cancer.
Targeted drug therapy
Currently this is still in the experimental stages, but we will describe it here. Its crazy cool, and hopefully the future of cancer treatment.
Another type of targeted therapy is medication containing radiation. You get a radiotracer, a drug which finds cancer cells. It does this by looking for PSMA (prostate-specific membrane antigen), a protein on the surface of cancer cells, but not on healthy cells. Then you get a PSMA-Pet (positron emission tomography) scan, which finds the cancer cells within your body and makes them visible.
Radionuclide therapy (molecular radiotherapy)
- If your prostate cancer has metastasized to the bones of your pelvis and spine, you may be a candidate for targeted radionuclide therapy.
- Or if your cancer has become castrate-resistant, you may be a candidate.
Several types of radionuclide medication exist. You may receive it in an infusion over several months. The cell-targeting molecule binds to the target and may help kill the cancer cells. This combination is called a radiopharmaceutical.
In another drug, the cell engulfs the drug, just like Pac-Man, and delivers the radiation inside the cancer cell.
Your targeted therapy is given over time and may last for months. Be sure to tell your doctor if you have side effects; your dose may need modifying.
Side effects
- Nausea
- Dry mouth
- You may have myelosuppression, which is a decrease in the production of red and white blood cells and platelets. This side effect causes several other side effects.
- Increased chance of infections (if you have too few white blood cells)
- Bruising or bleeding (if you have too few platelets)
- Fatigue (if you have too few red blood cells)
Another radiopharmaceutical is for men with
- Metastasis that may be treatable with surgery or other therapy
- Suspected recurrence
Because this drug and PET/CT scan combination successfully reveals metastasis or lack of before surgery, it could be used to keep patients from having unnecessary surgery.
In an earlier time it was possible only to suspect the presence of recurrence with biochemical evidence (elevated PSA levels). It is now possible to make the suspicion visible. With radiopharmaceuticals and a PET scan, your doctors and you can see the location of recurrence. This information informs the approach to therapy.
Side effects
- Headache
- Altered taste
- Fatigue
- Risk of hypersensitivity reactions to the radiopharmaceutical piflufolastat F 18, especially for patients allergic to other drugs
- Risk for misdiagnosis. Piflufolastat F 18 may find and attach to other types of cancer and certain other non-malignant conditions.
- Radiation risks, because radiation exposure is cumulative, which increases the risk of cancer.
You have had a lot of emotional weight on you if you have recently been diagnosed with prostate cancer. You can get support from people, groups, websites, activities, and, of course, family. Cancer treatment focuses on your life with doctors and nurses and at treatment centers or hospitals. But your life outside of these places is important, too, to your well-being and outlook. It is there that many people see what is most important in their lives.