In the United States an estimated 40,000 men per year are chemically castrated as a treatment for metastasized prostate cancer. In many cases the growth of this type of cancer is dependent on testosterone, at least in the initial phase. In the Netherlands 7,000 new patients are diagnosed with prostate cancer each year. Until well into the 1980s the castration was performed surgically, which was certainly no joke for the patients involved. True, they were mostly older men, but even so. . . Nowadays the procedure is carried out chemically, usually with prolonged-release depot injections in the abdominal wall. The injections consist of gonadorelins, or lh-rh analogues. lh-rh stands for luteinizing hormone-releasing hormone. These medicines act mainly on the brain (hypothalamushypophysis). Examples include Suprefact 9.45 mg injection, Zoladex 10.8 mg injection, Lucrin 11.25 mg and Decapeptyl 3.75 mg.
The most frequent side-effects are tiredness and headache. Hair growth also decreases, and the hair becomes softer. Approximately 5 per cent of testosterone production takes places in the adrenal glands. In order to shut down production completely, so-called antiandrogens can be given in addition. These include Androcur 50 mg (250-300 mg per day), Anandron 300 mg (150-300 mg per day), Flutamide 250 mg (750 mg per day) and Casodex 50 mg (50 mg per day). One of the most troublesome side-effects of these drugs is painful breast formation. This can be prevented by one-off radiation treatment of a small area around both nipples.
When the patient starts on a course of an lh-rh analogue an additional dose of an antiandrogen is given in order to prevent a flare-up of the disease due to stimulation of the hypophysis and the resultant rise in testosterone production. After four weeks the gland is saturated with lh-rh analogue and hence the production of testosterone is blocked. Long-term treatment with an lh-rh analogue plus an antiandrogen is called a ‘total’ androgen treatment. This is mostly used in men with metastasized prostate cancer. Hormonal treatment of metastatized prostate cancer is effective in between 70 and 80 per cent of cases.
The average time lapse between the start of the hormonal treatment and the emergence of a hormone-resistant illness, is between a year and a half and two years, meaning that after that time the hormonal treatment no longer has sufficient effect. Although the usefulness of continuing treatment with an lh-rh compound in the case of hormone-resistant prostate cancer has not been incontrovertibly established, the experts believe that when the cancer worsens during treatment with an lh-rh analogue it is better to continue the therapy. This avoids the eventuality that besides the hormone-resistant prostate cancer cells there is a resurgence in the growth of cancer cells still sensitive to (and hence inhibited by) the hormonal treatment. Although there is no conclusive proof, there are strong indications for the correctness of this assumption, since it was shown by research in the 1990s that the period of patient survival was shorter when the hormone treatment had been terminated, compared with patients with whom the treatment had been continued. This is why even in cases where chemotherapy is given, treatment with an lh-rh is in fact continued. Even in the case of chemical castration — as the name implies, not much is left of the testicles. Prostate cancer patients in effect become eunuchs.
chapter six