Men living with metastatic prostate cancer now have more options available.
Cancer of the prostate gland is the most common cancer affecting men. Most of the time when prostate cancer is diagnosed and treated, the tumor is still confined to the gland. But when this cancer becomes metastatic and spreads to other parts of the body, treatment can stop cancer growth, control pain and other symptoms, and extend survival. In this way, prostate cancer is somewhat unusual compared with other types of cancers, which are more difficult to treat when they spread.
If a man has already been treated for prostate cancer with surgery or radiation, rising levels of PSA may indicate that his prostate cancer has returned. (PSA refers to “prostate-specific antigen,” a protein produced by the prostate gland.) PSA may rise even though tests are unable to detect any obvious disease in the bone or other organs. For these men the disease is considered “micrometastatic,” meaning that cancer cells are believed to be present somewhere in the bloodstream, but they cannot be detected with the usual imaging tests.
Hormonal Treatments for Metastatic Prostate Cancer
The standard of care for treating metastatic prostate cancer is hormonal therapy. This type of treatment is aimed at lowering the production of testosterone and other male hormones. Testosterone acts like a fuel, encouraging prostate cancer to grow. Without testosterone and other male hormones, prostate cancer goes into remission—often for many years. Testosterone production can be reduced in different ways:
Injecting an LHRH analog or implanting it under the skin These hormonal medications mimic a natural hormone that is secreted by the hypothalamus, a part of the brain that controls body temperature, hunger, thirst, and other functions. They can fool the body into shutting down testosterone production in the testicles. LHRH analogs include leuprolide (Eligard, Lupron, Viadur, and others), goserelin (Zoladex), triptorelin (Trelstar), and histrelin (Supprelin, Vantas). These injections and implants come in different preparations that last for one, two, four, six, and 12 months at a time.
Using a combined hormonal approach Another way to block testosterone is with medications called antiandrogens. Examples include flutamide (Eulexin and others), bicalutamide (Casodex and others), and nilutamide (Nilandron). Doctors give these pills in combination with LHRH analog injections or implants to block the growth of prostate cancer cells fueled by male hormones. Antiandrogens are able to block testosterone produced by the adrenal glands and any other testosterone that was not already blocked by an LHRH analog.
An important note: Because one of the liver’s important jobs is to break down medications as well as toxins in the body, it needs to be checked with periodic liver function blood tests, especially if you are taking antiandrogens. Tell your doctor immediately if you experience nausea, vomiting, stomach pain, excessive tiredness, loss of appetite, flu-like symptoms, dark yellow or brown urine, and/or yellowing of the skin or eyes. It’s crucial to remember that herbal remedies, megadoses of vitamins, or excessive amounts of alcohol can prevent the liver from breaking down antiandrogens and can cause abnormal test results.
When first treated with hormonal therapy, metastatic prostate cancer usually responds to hormone treatments and goes into remission. But sometimes cancer cells can resist treatments. Prostate cancer cells can “learn” how to grow without male hormones. Doctors call this condition hormone-refractory prostate cancer.
In some cases of hormone-refractory prostate cancer, simply stopping antiandrogen treatment causes a man’s PSA level to go down and his prostate cancer to shrink or disappear. In other cases, doctors prescribe different antiandrogen drugs to try to slow cancer growth.
Treatments on the Horizon
Researchers are developing a number of new medications for the treatment of metastatic prostate cancer. Some of the most promising include:
Abiraterone This drug works by blocking the hormones that fuel the growth of metastatic prostate cancer. Early clinical trials showed that abiraterone helped shrink metastatic prostate tumors and slowed their growth. Currently, abiraterone is being studied in a large multi-center clinical trial.
MDV3100 This new drug has been shown to help stall the growth of metastatic prostate cancer in men whose tumors.
Ipilimumab (MDX-010) In clinical trials, this drug has been shown to be effective in men whose metastatic prostate cancer does not respond to hormonal treatment or chemotherapy. Ipilimumab blocks a molecule that reduces the immune system’s ability to kill tumors, including metastatic prostate cancer cells. By blocking this molecule, ipilimumab helps restore the ability of the immune system to destroy tumors.
Bisphosphonates Because lowered testosterone levels lead to a loss of calcium in the bones, which weakens them, doctors often give drugs called bisphosphonates to men with metastatic prostate cancer. Bisphosphonates help manage bone pain and minimize the risk of fractures to the hip and spine. Some research suggests that combining bisphosphonates with the drug leuprolide may benefit men with metastatic prostate cancer. These medications are approved for men whose metastatic prostate cancer does not respond to first-time hormonal therapy.
Sometimes doctors recommend chemotherapy as a treatment for hormone-refractory prostate cancer. Doctors typically reserve chemotherapy for men who fall into one of three groups:
Those with fast-rising PSA levels When the PSA level begins doubling or tripling so rapidly that hormone treatments can’t control it, chemotherapy may be an option.
Those who are developing symptoms If a man with metastatic prostate cancer is losing weight, looking pale, and experiencing physical distress, chemotherapy should be considered.
Those who have significant metastatic disease that is growing rapidly Sometimes these men are treated with radiation aimed at multiple tumor sites. However, numerous radiation treatments to the bone can reduce the number of red blood cells in the bone marrow and can lead to anemia. Using chemotherapy reduces the need for radiation.
Docetaxel (Taxotere) in combination with prednisone is the standard chemotherapy that has been approved for use in men with hormone-refractory metastatic prostate cancer. Mitoxantrone (Novantrone and others), another chemotherapy, has also been approved for these patients. Although this drug has not been shown to extend survival, it does improve pain control.
It’s important to talk with your doctor about the possible side effects of prostate cancer and its treatment. Members of your health care team can help you reduce and manage these symptoms to improve your quality of life.
Pain Prostate cancer that spreads to the bone can lead to pain. Medications such as bisphosphonates help relieve some of this pain. In addition, radiation is often used to manage bone pain.
Men with metastatic prostate cancer typically receive 15- to 20- minute daily radiation treatments for about two weeks. It usually takes a week before the pain and discomfort begin to ease. There are several types of radiation used, including external beam radiation, intensity-modulated radiation, and radioactive isotopes.
Hot flashes In most men treated with hormonal therapy for their metastatic prostate cancer, hot flashes are fairly limited. If you are especially troubled by hot flashes, ask your doctor about medications such as low doses of female hormones (estrogen or progesterone) that can help.
Osteoporosis (increased risk of bone fractures) Lowered testosterone leads to a loss of calcium, which may cause osteoporosis. Treatment with bisphosphonates can help reverse the effects of osteoporosis. This is especially important to reduce bone pain as well as the risk of fractures to bones, including the hip and spine.
Loss of erections (erectile dysfunction) Sometimes men experience erectile dysfunction when being treated for prostate cancer. If you are experiencing this side effect, discuss your concerns with your doctor. He or she will be able to recommend a number of possible treatments and can consult with other members of your team to assist you. Some approaches used to manage this side effect include:
A drug such as sildenafil (Viagra and others), vardenafil (Levitra), or tadalafil (Cialis) can improve erections for some men.
A penile implant that makes it possible to have and keep an erection. This approach involves surgery.
Urethral suppositories or injections of prostaglandin E1 (alprostadil) to promote erections.
Vacuum devices that draw blood into the penis for an erection.
Weight gain When men’s testosterone levels go down, their metabolism can change, causing them to retain fluid and gain weight. Hormone treatments can result in a loss of muscle mass. Stay active by walking, doing chores, and engaging in physical activities you enjoy. Weight training can also help build and maintain muscle strength and structure.
Fatigue Some days you may feel so tired that even simple daily activities leave you exhausted. But over time, light physical activity or gentle exercise—short walks building up to longer walks—goes a long way toward helping relieve fatigue. Taking 30-minute “power naps” during the day can also help. These naps give you a boost without disrupting your sleep schedule.
As someone living with metastatic prostate cancer, the decisions you make may have a major impact on your life. To make the decision-making process easier, consider the following:
Choose a physician you’re comfortable with. Make sure he or she specializes in your type of cancer.
Ask questions until you get the answers you need. Be assertive and persistent about getting a clear understanding of your options and possible outcomes.
Know what to expect. Discuss treatment goals with your doctor and make sure you are aware of possible side effects and how to manage them.
Review your financial situation. Determine whether you need help with the costs of treatment or other related expenses, such as transportation, home care, child care, and travel to and from treatment.
Make sure you have the support you need. Review your support network of family and friends, health care providers, and organizations such as CancerCare. In the sidebar, we explain the different free services CancerCare offers to anyone affected by cancer.
Q. I find hormonal therapy very difficult, emotionally. I’ve read that this reaction might be related to a lack of estrogen. If that’s the case, why aren’t estrogen patches used more widely?
A. There is some suggestion that lowered estrogen could have something to do with your difficulties. But using a patch could create its own problems. For instance, estrogen can lead to fluid retention, congestive heart failure, and an increased risk of blood clots. A lower dose of estrogen would be safer but also less effective. This is why estrogen patches and supplements aren’t used as much as they have been in the past. You might consider individual counseling, which helps many people cope with the emotional challenges raised by cancer and its treatment.
Q. Is it appropriate to have radiation treatment for metastatic prostate cancer even though I was already treated with radiation before the cancer metastasized?
A. In general, if you have already had radiation to the pelvis near the prostate gland, more radiation to that area would not be recommended. But if you develop a problem such as pain in the bones of the arms, legs, or spine, and those areas have not been exposed to radiation before, you most likely could be treated with radiation to those areas.
Q. When prostate cancer metastasizes, does the PSA level go up?
A. In general, higher-than-normal PSA levels signal that something has changed in the prostate gland. If a man has been treated for prostate cancer with surgical removal of the gland, most physicians believe that PSA levels should be very low—that is, less than 0.2 nanograms per milliliter (ng/mL) of blood. If the PSA number goes up during two consecutive readings after surgery, it may mean that prostate cancer has returned. In men who have been treated with radiation, doctors look for three consecutive rises in the PSA number. They may also order other tests to further evaluate the situation.
Q. Can I continue to do exercise, like brisk walking, when I am treated for metastatic prostate cancer?
A. It’s certainly a good idea to engage in as much physical activity as is comfortable. Exercise helps promote heart health and can relieve stress and fatigue. In general, activities like walking or swimming are preferable to high-impact activities, such as jogging. Men who are having a difficult time finding an exercise routine that works for them should seek the help of a physical therapist or rehabilitation specialist.