New Treatments for Prostate Cancer
Researchers around the world are busy developing new drugs, new procedures, and new treatment approaches that appear promising for men with prostate cancer. Many of the new treatments are showing encouraging initial results and could prove beneficial to men fighting this complex and common disease.
While the standard prostate cancer treatments (surgery and radiation) have been fairly successful in treating the disease, they often cause side effects that can negatively impact a man's quality of life. The new treatments attempt to provide men with safer and more effective treatment alternatives that will enable them to live longer, better-quality lives once the disease has been treated. Although very little long-term data is available, men may want to discuss the newer therapies with their doctors to see whether or not they could benefit from one these methods.
New Types of Treatments
Newer treatment options that are currently approved or under study for prostate cancer include:
- Cryosurgery
- Chemotherapy
- Biological therapy
- High-intensity focused ultrasound
- Proton beam radiation therapy
Cryosurgery
Cryosurgery, also known as cryotherapy or cryoablation, is a treatment for localized prostate cancer that involves freezing tissue to kill cancer cells.
With this approach, several small hollow probes (needles) are inserted into the prostate through the perineum (the space between the scrotum and the anus). Then, a very cold gas (argon gas or liquid nitrogen ) is delivered to the prostate through the needles, freezing the prostate cells and cancer cells, followed by a second gas to reheat the tissue. The cycle of freezing and thawing destroys the cancer cells and some surrounding healthy tissue.
Cryosurgery has been around for years, but is now gaining additional attention due to newer technologies which have improved the procedure. The original attempts to use the therapy for prostate cancer resulted in unacceptable side effects, but doctors are hopeful that the advancements have made cryosurgery safer. Possible side effects of cryosurgery include temporary or lasting urinary or sexual problems.
Chemotherapy
Chemotherapy is a treatment for prostate cancer that uses drugs to kill rapidly growing cells, including cancer cells. It may be used to treat advanced prostate cancer that has spread outside of the prostate gland or for prostate cancer that does not respond to hormone therapy. New studies are also looking at whether chemotherapy could be beneficial for early prostate cancer if used for a short time after radiation therapy or surgery.
With chemotherapy, anti-cancer drugs are injected into a vein or given by mouth. The drugs enter the bloodstream and travel to areas throughout the body. Common chemotherapy drugs (usually given in combinations) include docetaxel, prednisone, estramustine, and mitoxantrone.
At one time, it was thought that chemotherapy was not effective in treating prostate cancer, but this opinion has recently changed. Like hormone therapy, chemotherapy may not result in a cure, but it may slow the cancer's growth and reduce symptoms of the disease, resulting in a longer life and improved quality of life. The side of effects of chemotherapy can be significant, but they are often temporary and go away once treatment is finished.
Biological Therapy
Biological therapy is a newer approach for treating prostate cancer that uses the body's immune system to fight cancer cells or control the side effects of other cancer treatments. This approach includes immunotherapy, targeted therapy, and anti-angiogenesis treatment.
- Immunotherapy helps the body fight cancer cells by inducing, enhancing, or suppressing an immune response. One of most recent immunotherapies to receive FDA approval is Provenge, a "cancer vaccine" for men with advanced prostate cancer that stimulates the immune system to attack the cancer cells.
- Targeted therapy uses non-chemotherapy drugs to target specific cancer cells and spare normal cells.
- Anti-angiogenesis is a targeted therapy that does not target cancer cells, rather it suppresses new blood vessels from developing in the tumor, preventing the cancer from growing.
Biological therapy is less invasive and less toxic than conventional treatments since it uses the body's immune system to fight cancer cells rather than to attack the cancer cells directly. Treatment may be given as pills, shots or through an IV (intravenous therapy).
High-intensity Focused Ultrasound
High-intensity focused ultrasound is a highly precise medical treatment that uses powerful sound waves to heat prostate tissue, causing cancer cells to die. Treatment involves inserting a small probe into the rectum which is used to deliver ultrasound energy at precise points in the prostate.
Results seen in prostate cancer patients to date have been promising. High-intensity focused ultrasound is still experimental in the United States, but it has been used in Europe for many years with some success. Use to date shows that it greatly reduces some of the side effects commonly seen with other prostate cancer treatments and produces results similar to those of surgery.
Proton Beam Radiation Therapy
Proton beam radiation therapy is a type of external radiation therapy that uses a beam of high-energy particles (protons) to target cancer cells. Like other types of radiation therapy, proton beam radiation therapy destroys cancer cells and stops them from growing. It is used to treat prostate cancer that has not spread outside of the prostate gland.
The primary advantage of proton beam radiation therapy, compared to other types of radiation therapy (which use x-rays), is that proton beams can be targeted more precisely on the tumor, resulting in less damage to the surrounding healthy tissue. This makes it possible to use a higher dose of radiation with proton therapy than is possible with x-rays.
While all radiation therapy can cause early and late side effects, they tend to be milder with proton beam radiation therapy because there is less damage to healthy tissues. Common side effects of radiation treatment are tiredness or fatigue and skin problems in the treatment area (such as sensitivity, redness, or swelling).
Proton beam radiation therapy has been in use for over 40 years, yet only a few medical centers in the United States currently offer this type of radiation therapy. Widespread use is limited due to the size and cost of the equipment involved with this therapy.