Hormone Treatment
Prostate cells and particularly prostate cancer cells grow in response to the male sex hormone testosterone. This was discovered in the 1950s and some of the earliest forms of treatment for prostate cancer were based around this. Originally men had their testicles removed to stop the testosterone production (orchidectomy), but more recently chemical means of producing the same effect have been produced.
Hormone treatment leads to the tumours and cancer cells shrinking but does not kill them, so whilst the cancer will be slowed it may not be cured. It does, however, offer the opportunity for other therapies such as radiotherapy to be utilised alongside to try to kill the cancerous cells.
Two main groups of hormone drugs are mainly utilised in hormone treatment. The first group are known as LHRH analogues, and are aimed at switching off the pituitary gland and thereby stopping it producing testosterone. These are given usually with drugs (known as anti-androgens) such as bicalutamide (Casodex®) or cyproterone acetate, which are used initially to block the action of testosterone at the level of the cells. These are then followed by LHRH analogues through injections of drugs like triptorelein (Decapeptyl®), goserelin (Zoladex®) or leuprolein (Prostap®) to block the hormone that causes release of the testosterone.
Once the injections have been started, the tablets can be stopped after a fortnight or so. Unfortunately these treatments don’t just act on the cancer cells but on all of the cells in the body, so men on these treatments lose their sex drive and erections, and quite commonly experience hot flushes not unlike the female menopause. Some men may also notice sore or enlarging breasts.
A new treatment, LHRH antagonist, is soon to be available.
Treatment of advanced prostate cancer with hormone therapy has been shown to be useful, with men responding well in 60 -70 %, reasonably well in 10-20% and showing no response in 10-20% of cases. (See Smith J. et al. Prostate Cancer – A comprehensive guide for patients).
