Advanced stage prostate cancer can present itself in one of two
ways: firstly, a patient can be diagnosed initially, based on biopsy
and clinical staging of the disease, at a Gleason stage that can
be considered advanced due to the aggressiveness of the cancer cells
seen in the pathologist's review. In some cases wherein the Gleason
stage may not be considered aggressive = 6, other diagnostic tests,
e.g. endo-rectal MRI may indicate that cells have escaped the prostatic
capsule, which could potentially cause a recurrence of the disease
after primary therapy. It has been shown that 20-30% of patients
have the disease recur after a primary therapy (surgery or radiation).
More commonly advanced stage disease presents itself after primary
therapy and a rise in PSA level is noted. In some cases, if the
increase is noted early and the PSA level has not exceeded 1.5 and
the patient did not have surgery, salvage radiation is an option
that has proven to be effective in curing approximately 25% of the
patients who failed primary therapy.
Typically, the usual course of treatment for advanced stage disease
is a form of hormonal therapy, also called androgen ablation that
seeks to remove testosterone from the system because testosterone
contributes to the growth of the cancer cells. You should note that
typical hormone therapies are NOT curative and that your system
will at some point become hormone/androgen independent (the cancer
recurs). Because of the complex nature of the disease, at the time
that the PSA begins to rise, you should consult with a medical oncologist
along with your urologist to determine what the best therapeutic
approach should be implemented for your situation.
Dr. Maha Hussain of the University of Michigan Cancer Center speaks about the controversy between intermittent and continuous androgen deprivation therapy.
The options that
are available are:
Orchiectomy - this is surgical removal of the
testicles to eliminate the roughly 90% of testosterone produced
by the testicles; obviously this procedure is permanent and cannot
be reversed. Other options to eliminate testosterone are noted as
follows.
LHRH agonists - the brain generates signals, luteinizing
hormone releasing hormone (LHRH), that cause the testicles to produce
testosterone. The single agents used in this protocol are usually
lupron or zoladex
Nonsteroidal antiandrogens - approximately 10%
of testosterone is produced by the adrenal glands; the utilization
of a nonsteroidal antiandrogen, such as, flutamide (Eulexin) or
bicalutamide (Casodex), in conjunction with one of the above procedures
is called complete androgen blockade (CAB) is theorized to help
improve survival, but very little evidence exists to support this
hypothesis. Additionally many patients that have been on CAB for
an extended period may experience a rise in PSA; in these cases
usage of the nonsteroidal antiandrogen should be stopped.
Other therapeutic options to consider, based on investigative
clinical experience or on-going clinical trials, are:
Intermittent Androgen Blockade (IAB) - as the
patient's PSA level normalizes, he may be cycled off and on the
hormonal blockade to extend the period of effectiveness of the hormonal
therapy before the patient becomes hormone refractory/androgen independent,
i.e. the diseases progresses
Herbal Therapy - certain herbal supplements, such
as PC-SPES and others, have been shown to have effects in controlling
both androgen dependent and androgen independent cancers. Given
that this class of treatment does not fall under the same guidelines
for testing, efficacy, etc. as other drugs, it is important that
you undertake their use only under the guidance of your doctor
Adjuvant
Therapy - prior to surgery or radiation; a discussion as to
the benefits of hormonal treatment
Intermittent
Hormonal Therapy – evolving technique designed to maintain
androgen dependence thereby prolonging survival and decreasing long
term side effects.
