LH-RH Agonists in Oncology

Hormonal treatment of malignant diseases came of age quite some years ago. Nevertheless, developments in this field are still progressing at a steady pace. During recent years, the detection of new endocrine feedback loops and the availability of new classes of hormonal agents made it possible to predictively interfere with hor mone actions. Besides the intellectual challenge of modulating the hormone system, there is an important new aspect associated with recent research on hormones and cancer: new developments have generally led to a reduction in treatment-induced morbidity. As aromataseinhibitors are substituted for adrenalectomy, controlled interference with the hypothalamic-gonadotrophic axis is likely to replace surgical removal of the relevant glands, i. e. , the pituitary gland or the gonads. With the detection of the luteinizing hormone releasing hormone (LH-RH), its structural analysis, and the synthesis of analogs of this decapeptide hormone, a tool became available not only for treatment of sterility or endometriosis but also for switching off gonadal activity in a reversible manner. Evidence has accumulated over the past few years that LH-RH agonists can serve as "medical orchiectomy" in prostate cancer. As a logical consequence, hypogonadotropic gonadal insufficiency induced by LH-RH agonists was investigated in patients with breast cancer. Of equal importance were the attempts to prevent infertility from cytostatic drugs by temporar ily suspending gonadal function.