hormonal therapy, ht
Overview of HT
Hormonal therapy, HT, involves any treatment that can lower the body’s
levels of the male sex hormones Testosterone (produced by the testes)
or other androgens (produced by the adrenal glands). Hormonal
Therapy is not a cure for Prostate Cancer and is at best palliative
in scope. It is targeted to the sites of action of Testosterone and
Di-hydrotestosterone within and outwith the prostate, wherever
prostate cancer cells may be present. HT therefore has the potential
to reach cancer cells that may be extraprostatic.
What Preparations are Available
- Oral medications taken daily – Anti androgens e.g. Cyproterone
Acetate, Casodex, Flutamide - -- Estrogens eg DiEthylStilboestrol
- Depot injections – once onthly e.g. Zoladex, Lupron, Lucrin
- Surgical removal of Testosterone producing tissue from the testes ( bilateral orchidectomy)
Hypothalamus-Pituitary-Gonadal Axis; Sites of Hormonal Action
(a) ORAL MEDICATIONS: Antiandrogens and Estrogens eg. Diethylstiloboestrol
ANTI- ANDROGEN eg.. Cyproterone Acetate, Casodex, Flutamide, act by inhibiting the production of Androgens (Including Testosterone) by the testes or Adrenals or by blocking their effects on the prostate.
The Main Advantage: That they block Testosterone of Adrenal origin.
The Main Disadvantage: Cost and compliance, since dosing may be up to three times per day.
ESTROGENS eg. Diethylstilboestrol These act by inhibiting the brain (Hypothalamus and Pituitary) from producing LH which itself stimulates the production of Testosterone. So Testosterone production is indirectly suppressed.
Main Advantage: Not Costly
Main Disadvantage: Implicated in the causation of Deep Vein Thrombosis, DVT’s (Life Threatening venous clots)
(b) DEPOT INJECTIONS- LHRH ANALOGUES: suppress the brain
(Hypothalamus) from producing LH, which in turn decreases the production of
Testosterone. However they cause an initial increase in Testosterone release,
which is short lived and potentially dangerous, but eventually leads to a
sustained decline in Testosterone production.
Main Advantage: Compliance better ; they come as monthly or 3- monthly depot preparations.
Main disadvantage : Costly
(c) SURGICAL REMOVAL OF TESTOSTERONE / Bilateral Orchidectomy
This is a minor surgical procedure in which the Testosterone producing tissue is
removed from within the scrotum. When performed as a subcapsular procedure, the
outer shells of the testes remain giving an almost natural feel and appearance.
Main Advantage: It is a one-time procedure ensuring good compliance.
Main Disadvantage: The psychological effect of emasculating the patient.
WHEN IS HT USEFUL
- Advanced and metastatic Prostate Cancer
- Early Prostate Cancer in Elderly/ Medically unfit
- Locally Advanced Prostate Cancer – Controversial
- Advanced and Metastatic Prostate Cancer.
HT is used to temporarily halt the systemic effects of Prostate cancer such as
anorexia, weight loss and obstructive symptoms. It can possibly circumvent or
delay the onset of complications due to metastases eg ureteral obstruction and
fractures. Often the cancer becomes hormone-resistant and advances further.
The approximate mean survival at this stage is 2 years.
- Early Prostate cancer in the Elderly/ Medically unfit.
In patients over 80 years of age, with limited life expectancy but who
desire treatment, HT can offer relief of symptoms. In younger patients
who are Medically unfit for more aggressive treatment, HT can be
administered with minimal morbidity.