Changing trends of prostate cancer in Asia

Although Asian people have the lowest incidence and mortality rates of prostate cancer in the world, these rates have risen rapidly in the past two decades in most Asian countries. Prostate cancer has become one of the leading male cancers in some Asian countries. In 2000, the age-adjusted incidence was over 10 per 100?000 men in Japan, Taiwan, Singapore, Malaysia, the Philippines and Israel. Although some of the increases may result from enhanced detection, much of the increased incidence may be associated with westernization of the lifestyle, with increasing obesity and increased consumption of fat. The differences in incidences between native Americans and Asian immigrants are getting smaller, reflecting a possible improvement of diagnostic efforts and changes of environmental risk factors in Asian immigrants. Nevertheless, the huge variations in incidences among ethnic groups imply that there are important genetic risk factors. The stage distributions of prostate cancer in Asian populations are still unfavorable compared to those of Western developed countries. However, a trend towards diagnosing cancer with more favorable prognosis is seen in most Asian countries. Both genetic and environmental risk factors responsible for elevated risks in Asian people are being identified, which may help to reduce prostate cancer incidence in a chemopreventive setting.     

Practical consequences of the validation of a mathematical model in assessment of partial androgen deficiency in the aging male using bioavailable testosterone

Partial androgen deficiency or the andropause in the aging male is a complex clinical and biochemical entity that needs to be analyzed at two levels of the constituent structure: the 'deep structure' should come to light with more intensive research, while the 'surface structure' holds the attention of investigators who focus on hormone measurements in the blood to help diagnose the andropause. In this study, it is recognized that bioavailable testosterone decreases progressively during the aging process. This physiological decline may be so important, or so close to castration levels, that aged men may experience numerous symptoms of hypogonadism. The assay for bioavailable testosterone was indirectly validated with a set of equations derived from our knowledge of the law of mass action at equilibrium, as proposed by Vermeulen and colleagues in 1999. With this mathematical model, we have shown that calculated free testosterone was highly correlated with bioavailable testosterone. It is therefore concluded that the evaluation of aged men's androgenicity should rely on at least one of these free testosterone assessments (bioavailable or calculated free testosterone) for the sake of reproducibility in the construction of the 'surface structure' of the andropause in the coming years.