SAJS 968 - GENERAL SURGERY.indd

The causes of prostate cancer are not well understood, but certain risk factors have been identified, namely age, ethnic group, family history, hormone levels and environmental inf luences. The role of androgens in the pathogenesis of prostate cancer remains unclear, but is thought to be pivotal. While androgenic stimulation is needed for prostate development and growth, serum testosterone levels have failed to distinguish benign from malignant disease. The responsiveness of prostate cancer to androgen withdrawal and the failure to develop prostate cancer in males castrated before puberty, and in individuals with an inherited 5-alpha-reductase deficiency, support this argument. However, the serum testosterone level decreases with age (0.25 0.40% annually), whereas the incidence of prostate cancer increases. Numerous studies have reported conflicting results concerning the relationship between serum testosterone level and prostate cancer risk. Ribeiro et al. reported an association between a low serum testosterone level and shorter survival time in men with metastatic prostate cancer, while both Schatzl et al. and Zhang et al. have shown a correlation between a low serum testosterone level and high-grade prostate cancer. Hoffman et al. have indicated that patients with prostate cancer and a low free testosterone (FT) level had more extensive disease and a Gleason score of 8 or higher. In the circulation, testosterone is specifically bound to sex hormone binding globulin (SHBG) (~66%) and nonspecifically to albumin (~33%), leaving only a small fraction unbound (~ 1 2%). Unbound free testosterone is considered to be the bioactive fraction able to diffuse across cellular membranes. The objective of this study was to evaluate the relationship between FT levels and various prostate cancer parameters.