Prostate Cancer Hormone Therapy Questioned
An increasingly common therapy used for localized prostate cancer may not bestow any survival benefits on the patient beyond those seen with a simple "wait-and-see" approach.
Men taking androgen deprivation therapy, which shuts off male hormones that can promote tumor growth, even had a slightly lower prostate cancer-specific survival rate, according to a report in the Journal of the American Medical Association (JAMA).
"This might give pause, and probably should give pause to people thinking about using this approach," says Dr. Robert Ennis, at St. Luke's Roosevelt and Continuum Cancer Centers in New York City. "There's always a gray area of patients. This might shift the balance."
But, Dr. Ennis adds, "This is not an absolute, definitive, end-of-story type study."
The research only looked at whether patients lived or died. There may be other outcomes of this therapy that would make it worthwhile, notes Dr. Ennis.
Researchers in the new study looked at 19,271 Medicare patients ages 66 and over, none of whom had received "definitive local therapy" such as surgery.
Forty-one percent of the participants had received primary androgen deprivation therapy (PADT) for an average of 18 months; the rest had simply waited and watched.
There was no increase in 10-year overall survival rates among men taking PADT compared with men undergoing conservative management.
In fact, 19.9 percent of those taking PADT died of their prostate cancer within 10 years, compared with only 17.4 of those on the waiting approach.
Experts say androgen deprivation therapy has been shown to have a benefit in other scenarios, for example, when added to radiation therapy.
"This teaches us something about how we practice medicine, and it does give us reason for pause," says Dr. Otis Brawley, chief medical officer of the American Cancer Society (ACS). "A lot of doctors give androgen deprivation therapy without any evidence that it's a good thing for early-stage prostate cancer.
“One of the reasons we're in such a quagmire on prostate cancer is so many doctors have practiced medicine not supporting the clinical trials but just treating it the way they think they ought to be treating it,” says Dr. Brawley.
"This is not the first research to show this,” notes Dr. Brawley. “There are clinical trials out there that already suggest this is not beneficial, but people have done it anyway.”
There is also evidence that androgen deprivation therapy can increase the risk of diabetes, stroke, and death, among other things.
"While it can be useful in a small number, it [can be] quite harmful and should not be used arbitrarily," says Dr. Brawley.
Standard treatments for when prostate cancer is still confined to the prostate include surgery, radiation or "waiting and seeing."
Senior author Dr. Siu-Long Yao, at the Cancer Institute of New Jersey, says, "Prostate cancer is not as typical as some of other cancers. It grows at a slower pace, and it tends to occur in men that are elderly, so there a lot of other things going on like heart disease or lung disease or kidney disease or diabetes.
“If you treat someone for prostate cancer, they could [still] drop dead from a heart attack,” says Dr. Yao. “The key in this disease where it grows slower is prediction. Who's going to drop dead of a heart attack and who's going to have problems with prostate cancer. It leads to complexity. It's a guessing game more so than in other cancers."
Now, however, more and more men, especially older men, are opting for PADT instead of the tried-and-true standards.
"A lot of men think surgery and radiation seem aggressive while observation seems like you're doing nothing," says Dr. Yao.
"Men and their physicians have started looking for an alternative, which has become hormonal therapy," notes Dr. Yao. "Use of [PADT] in this setting has grown tremendously in the last decade or two. It is the second most popular treatment [after surgery] but, in spite of that, nobody has really studied whether it works or not."
Always consult your physician for more information. |
Prostate cancer is the most common cancer among men, excluding skin cancer. American Cancer Society (ACS) estimates for 2008 include 186,320 new cases of prostate cancer in the US.
Year 2008 estimates include 28,660 deaths occurring from prostate cancer in the US alone, making it the second leading cause of cancer death in men.
All men are at risk for prostate cancer. The risk increases with age, and family history also increases the risk.
African-American men are more than twice as likely to have prostate cancer than Caucasian men, and nearly a two-fold higher mortality rate than Caucasian men.
There are usually no specific signs or symptoms of early prostate cancer - which is why prostate screening is so important.
An annual physical examination, prostate-specific antigen (PSA) blood test, and digital rectal exam (DRE) provide the best chance of identifying prostate cancer in its earliest stages.
The following are the most common symptoms of prostate cancer:
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weak or interrupted flow of urine
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urinating often (especially at night)
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difficulty urinating or holding back urine
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inability to urinate
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pain or burning when urinating
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blood in the urine or semen
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nagging pain in the back, hips, or pelvis
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difficulty having an erection
There are several types of hormone therapy, including the following:
orchiectomy - the surgical removal of the testicles to prevent the male hormones that stimulate growth of the prostate cancer from being produced.
LHRH (luteinizing hormone-releasing hormone) analogs - drugs that decrease the amount of testosterone produced in a man's body by interfering with the normal chemical signals sent from the pituitary gland in the brain to the testicles.
Medications include Lupron, Viadur, Eligard, Zoladex, and Trelstar.
anti-androgens - substances that block the body's ability to use testosterone, because even after orchiectomy or LHRH-analog treatment, a small amount of testosterone may still be produced in the body. Other hormonal drugs may be used for periods of time during treatment. Medications include Eulexin, Casodex, and Nilandron.
LHRH antagonist (Plenaxis) - used on a very limited basis due to serious allergic reactions by some persons. This medication is given by injection.
Always consult your physician for more information.
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