Prostate Cancer In Asia Research Articles

Changing demography of prostate cancer in Asia

There has been a recent trend in Asia towards increasing incidence of prostate cancer, with some low-risk regions, such as Japan and Singapore, reporting a more rapid increase than high-risk countries. In this study, age-specific and age-standardised (world) incidence rates and mortality rates for prostate cancer in Asian countries for 1978–1997 were retrieved and compared. The results confirm that the incidence of prostate cancer has risen by 5–118% in the indexed Asian countries. Incidence at centres in Japan rose as much as 102% (Miyagi 6.3–12.7 per 100,000 person-years) whilst the incidence in Singaporean Chinese increased 118% from 6.6 to 14.4 per 100,000 person-years. The lowest incidence rate recorded was in Shanghai, China and the highest rates were in Rizal Province in the Philippines, although still much lower than those in the United States of America (USA) and many European countries. Whilst the absolute value of the increase is not comparable to North American and European populations, the incidence ratio in many Asian centres is similar to that of the high-risk countries. The mortality data for prostate cancer showed a similar rising trend. The increases in age-adjusted mortality rates per 100,000 person-years, adjusted to the world standard, ranged from 50% in Thailand to 260% in Korea. The difference may be partly due to genetic polymorphism in the androgen receptor and androgen metabolism pathway enzymes as well as to dietary or environmental factors. In particular, phytochemicals, such as isoflavonoids and tea polyphenols, which are common in Asian diets showed promising anti-mitotic activity in animal and clinical studies. In conclusion, with gradual Westernisation, many Asian countries may be losing their cultural protective factors and acquiring high-risk ones. A better understanding of how these factors interact to cause prostate cancer through further studies with a multi-ethnic perspective will facilitate appropriate public health strategies to minimise high-risk factors and maintain protective factors and keep prostate cancer at bay.

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.

The Role of Hormonal Therapy in the Treatment of Locally Advanced Prostate Cancer—Regional Perspectives: Asia

Despite a lack of data on the management of prostate cancer in Asia, the 1st Conference on Asian Trends in Prostate Cancer Hormone Therapy, held in 2001, put forward recommended consensus guidelines. However management of the disease is influenced by several factors including culture, philosophy and, particularly, economics. A survey in the Philippines showed that the main factors considered when choosing treatment are age of the patient and its cost. There is considerable variation in prostate cancer morbidity and mortality among the Asian countries but the incidence has been rising in recent years due to improvement in diagnosis. Treatment of the prostate cancer patient is individualised based on assessment of the biological potential of the disease, his life expectancy and his preferences. There is a need for large, randomised clinical trials to determine the efficacy of the newer modes of androgen ablation used as neoadjuvant and adjuvant therapy to external beam irradiation and radical prostatectomy. It is vital that Asian countries are part of this global survey.