There are significant geographic and ethnic differences in the incidence of prostate cancer, with the highest rates in Australia/New Zealand, the Caribbean and Scandinavia and lower rates in Asia and North Africa. Worldwide, prostate cancer has the second highest incidence rate of all malignancies in men. In the United States, the incidence of prostate cancer has surpassed that of lung cancer as the number one health risk for men, with the American Cancer Society estimating that there were approximately 217,730 new cases of prostate cancer in the United States in 2010, and 32,050 deaths will occur from this disease. In Europe, about 2.6 million new cases of prostate cancer are diagnosed each year, and prostate cancer accounts for 11% of all male cancers and 9% of all male cancer deaths, while the incidence of prostate cancer in Asia is much lower than in Europe and the United States, but has been on the rise in recent years. In China, the incidence of prostate cancer was 1.71 per 100,000 population and the mortality rate was 1.2 per 100,000 population in 1993; the incidence rate increased to 2.0 per 100,000 population in 1997 and 3.4 per 100,000 male population in 2002. Another set of data from the National Cancer Control Research Office/National Tumor Registry collecting 30 registries nationwide showed that the incidence of prostate cancer was 1.96 per 100,000 population from 1988 to 1992, 3.09 per 100,000 population from 1993 to 1997, and 4.36 per 100,000 population from 1998 to 2002 [14]. 1979 In Taiwan, China, there were only 98 new cases of prostate cancer; in 1995, the number rose to 884, with an age-standardized incidence of 7.2/100,000 population, and in 2000, there were 635 deaths with a mortality rate of 5.59/100,000 population. In 2007, the incidence of prostate cancer in men reported by the Shanghai Center for Disease Control and Prevention was 11.81/100,000 people, ranking fifth among male malignancies. Prostate cancer patients are predominantly older men, with a median age of 72 years for new diagnoses and a peak age of 75-79 years. In the United States, greater than 70% of prostate cancer patients are older than 65 years of age; it is rare in men younger than 50 years of age, but greater than 50 years of age, the morbidity and mortality rates increase exponentially. The likelihood of prostate cancer in individuals younger than 39 years of age is 0.005 percent, increasing to 2.2 percent (1/45) in the 40 to 59 age group and to 13.7 percent (1/7) in the 60 to 79 age group. The risk factors for prostate cancer are not fully understood, but some of them are well recognized. One of the most important factors is genetic. If a first-degree relative (brother or father) has prostate cancer, his or her risk of developing prostate cancer increases by more than a factor of 1. The relative risk increases by a factor of 5 to 11 when two or more first-degree relatives have prostate cancer. Patients with a positive family history of prostate cancer are diagnosed approximately 6 to 7 years earlier than those without a family history. A subpopulation (approximately 9%) of the population with prostate cancer is truly hereditary prostate cancer, meaning that three or more relatives have the disease or at least two have early onset (before age 55). Many studies on genetic polymorphisms and genetic susceptibility to prostate cancer are currently underway and will provide genetic evidence to explain the occurrence of prostate cancer. Exogenous factors can influence the progression from latent to clinical prostate cancer. The identification of these factors is still under discussion, but a diet high in animal fat is an important risk factor. Other possible risk factors include lack of exercise, lignans, low intake of isoflavones, and excessive intake of cured meat products. Sunlight exposure is negatively associated with prostate cancer incidence, and sunlight increases vitamin D levels, which may therefore be a protective factor for prostate cancer. In Asia, where the incidence of prostate cancer is low, green tea consumption is relatively high, and green tea may be a protective factor for prostate cancer. In conclusion, genetics is an important risk factor for the development of the clinical form of prostate cancer, and exogenous factors may have an important influence on this risk. The key issue now is that there is insufficient evidence to confirm that lifestyle changes (lowering animal fat intake and increasing intake of fruits, grains, vegetables, and green tea) reduce the risk of developing the disease. There are studies that support these claims, and this information can be provided to family members of men with prostate cancer who come in asking about the effects of diet.