The aetiology and pathogenesis of prostate cancer.

The incidence of prostate cancer is increasing, particularly in western countries, but, despite this, its aetiology and pathogenesis remain unclear. Epidemiological studies have suggested a range of possible aetiological factors (e.g. high saturated fat intake, low intake of carotenoids, vasectomy and other sexual factors, high serum androgen levels, and a family history of prostate cancer), although results have been contradictory in many cases. A review of the literature suggests that there may be differences in the importance of these factors in younger (< 60 years) and older patients. In particular, there is growing evidence for the existence of an hereditary form of prostate cancer, with an early age of onset, an independence for dietary and other environmental factors, and an aggressive natural history. There is also increasing evidence to suggest that the pathogenesis of the disease in Japan, with its markedly different incidence rates for clinical disease (as opposed to 'latent' or 'histological' disease), may be different to that in North America. The evidence for a 'two-disease' theory of prostate carcinogenesis is discussed.