Prostate cancer is a disease in which malignant tumor cells originate from the prostate gland. These malignant tumor cells are abnormal cells in the body that grow out of control and have the potential to metastasize to other parts of the body. Prostate cancer is the most common malignant tumor in men in the United States other than skin cancer, and has the second highest mortality rate of all malignant tumors. In 2005, the incidence of prostate cancer was the 9th most common malignant tumor in Chinese men. With the accelerated aging of the Chinese population and changes in lifestyle, the incidence of prostate cancer in some major cities has increased rapidly in the last decade and has become the most common tumor in the genitourinary system, ranking 5th in all malignant tumors in men. Prostate cancer cells can “travel” through the body with blood or lymphatic vessels and can “settle” in organs outside the prostate (called metastasis), destroying the function of these organs and threatening life. Bone is the most common site of metastasis in prostate cancer, and when bone metastases occur, the bones become fragile and easily fractured. Metastatic prostate cancer may also cause weight loss, fatigue, and other discomforts. Metastases from prostate cancer can have serious consequences, but most prostate cancers do not metastasize if caught early, and metastasis from prostate cancer is usually slower than from most other malignancies. On average, for every 1,000 patients diagnosed with prostate cancer in the United States, only 2 die from prostate cancer within 5 years, and the 5-year survival rate is second only to skin cancer (excluding melanoma) among all malignancies. The risk of death from prostate cancer increases 5 years after the diagnosis of prostate cancer. In the United States, 32,050 patients died of prostate cancer in 2010 (217,730 new prostate cancer diagnoses in 2010). China has a much lower rate of early diagnosis of prostate cancer patients than the United States, a higher percentage of patients who develop metastases, and a lower prostate cancer survival rate than the United States. Some studies have shown that most men can find prostate cancer cells in the prostate gland by age 75, but far fewer patients are actually diagnosed with prostate cancer. Many older men who have prostate cancer cells in their bodies, even without any treatment, do not experience any health risks from prostate cancer, and the person and the tumor “coexist in harmony”, which is different from many other malignancies. However, some prostate cancers develop quickly and are prone to metastasis, which can be life-threatening. Therefore, there are many types of prostate cancer, some of which are slow to develop, do not metastasize, do not threaten one’s health and life, and do not require treatment, while others are fast to develop, may metastasize, and are life-threatening, and require prompt and aggressive treatment. Unfortunately, medical science is not quite ready to determine which types of prostate cancer need treatment and which do not. There are two cases of prostate cancer diagnosis and treatment: over-diagnosis and over-treatment and untimely diagnosis and delayed treatment. In developed countries in Europe and the United States, overdiagnosis and overtreatment are more common; while in China, due to the different levels of economic and social development and the level of awareness of prostate cancer, untimely diagnosis and delayed treatment are more common. The treatment of prostate cancer brings more or less unpleasant side effects to the patient, and the treatment of patients who do not need it will reduce their quality of life and increase their financial burden. On the other hand, it is important to recognize that prostate cancer has become the second most common malignant tumor in men after lung cancer in developed countries in Europe and the United States, and one of the ten most common malignant tumors in men in China, and that delayed treatment for patients who are still in the early stages and need treatment can lead to tumor metastasis and threaten patients’ lives.