Prostate cancer cells require androgens (testosterone) in order to grow. Androgens can be testicular or adrenal in origin.
The secretion of testosterone is stimulated by the direct action of luteinising hormone (LH) on receptors located on specialised cells (Leydig cells) found in the testes. LH itself is stimulated by luteinising hormone-releasing hormone (LHRH) produced by the pituitary. Thus LHRH indirectly regulates the secretion of testosterone from the testes.
The adrenals secrete precursors, which are converted into androgens in the peripheral tissues and in the prostate itself. Removing androgens is an effective way of temporarily reducing the tumour bulk and delaying growth.
There are at least 4 ways of reducing the effects of testosterone. These are:
- injections of LHRH agonists that stop the testicles from making testosterone
- anti-androgens tablets that block the effects of testosterone in the body
- surgically removing the testicles, or the part of the testicles that produce testosterone
- tablets of the female hormone oestrogen, which stops the release of testosterone.