ABSTRACT

Prostate cancer remains the most frequently diagnosed tumor in the Western world, and its incidence is increasing also in Asian countries in parallel with ongoing changes in lifestyle. There are encouraging developments owing to the improved possibility of the early diagnosis of prostate cancer. Therapeutic approaches for non-organ-confined disease remain limited, however. Endocrine therapy is based on the pioneering work by Huggins and Hodges, who first demonstrated that withdrawal of androgens leads to retardation of prostate cancer growth1. Considerable efforts in prostate cancer research are being undertaken to improve the understanding of signal transduction pathways of steroid and peptide hormones, growth factors, cytokines and neurotransmitters. Signal transduction research is focused either on mechanisms underlying tumor progression to therapy resistance or on identification of early changes, which are a characteristic feature of clinically significant prostate tumors. Results obtained in these studies could also improve prostate cancer chemoprevention in the future. The development of resistance towards endocrine therapy is associated with multiple molecular alterations and the disregulation of expression of growth-regulatory molecules or their receptors. In some cases, growth factors or cytokines exhibit pleiotropic effects on prostate cancer cells. Activation of different signalling pathways by the same molecules in diverse cell lines could result in either growth stimulation or inhibition.