New (Experimental) Treatment Option for Prostate Cancer
by William J. Catalona, M.D.

    Intermittent Hormonal Therapy is a new, experimental treatment option for prostate cancer.

Previous Use of Hormonal Therapy

    Hormonal therapy is usually effective in the treatment of prostate cancer, especially for patients who have had recurrence of their cancer after surgery or radiation therapy.

    The principle of hormonal therapy is that the male hormone, testosterone, stimulates prostate cancer cells to grow and spread.  If the testosterone concentration in the blood is reduced to low levels, most prostate cancer cells will die or go into a dormant state for an indefinite (though unpredictable) period of time.

    In the past, hormonal therapy for prostate cancer involved the continuous administration of female hormones by mouth or by having the testicles removed.

    Recently, new medications are available to achieve the same results with fewer risks, and their effects are reversible when they are discontinued.

    The side effects of hormonal therapy can include reduced sexual desire and sexual function, “warm waves” (similar to “hot flashes” experienced by women during menopause), dry skin, and slowing of the growth of facial hair.

    With prolonged hormonal therapy, there can be loss of muscle mass (unless a vigorous exercise program is followed), loss of bone density (osteoporosis), anemia, and loss of energy.  Some forms of hormonal therapy can cause breast enlargement, gastrointestinal upset, blood clots, fluid retention, shortness of breath, and increased risk for heart attack.


New Use of Intermittent Hormonal Therapy

    Recent studies have shown that hormonal therapy may be give intermittently, thus providing the patient with a “vacation” from its side effects.

    A commonly used program for intermittent hormonal therapy involves taking to different types of medication: (1) a pill for 10 days and (2) injections of another kind of medication three months apart.

    A testosterone “flare” response occurs during the first 10 days after the injection (Lupron or Zoladex).  That testosterone “flare” in the first 10 days could cause the tumor to grow.

    The 10-day course of an oral medication (such as Casodex or Eulexin) along with the scheduled injection blocks the testosterone “flare” response that occurs during the first 10 days after the injection.  This 10-day course of oral medication to accompany injection is an essential component of the intermittent hormonal therapy.


Illustration

    The way this therapy works is as follows.  A man previously treated with radiation therapy develops a rising PSA level that reaches 4 on December 31.  The rising PSA is an indication that the cancer has recurred.

    On January 1, he would begin to take a 10-day course of Casodex pills.  On January 2, he would be given a Lupron injection that would stay in his system for three months.

    On April 1, he would check his PSA level (which would probably be very low) and then receive his second 3-month Lupron injection.

    On July 1, he would check his PSA level again.  If it is still low, he would stop the hormonal therapy and monitor his blood PSA level until it reaches a level 4 again, which may take six months to a year or more.  During this time, he would recover from the side effects of hormonal therapy.  When the PSA level is once again 4, he would begin another 6-month cycle.

    Although intermittent hormonal therapy is experimental, preliminary clinical studies suggest that the results appear to be equivalent to those of continuous hormonal therapy.