Despite advances in detection and treatment, prostate cancer as a common malignancy is still unknown. Recently, Professor Richard Hodson in the journal Nature posed four of the most important unanswered questions for us to ponder. 1. What causes prostate cancer? Worldwide, prostate cancer is the second most common malignancy in men, second only to lung cancer. Identifying some preventable cause of this disease may reduce the number of the disease. Cancer risk increases with age, with genetic factors accounting for approximately 5 to 9 percent of the risk. men with mutations in the BRCA2 gene have a 5-fold higher cancer risk than those without mutations. Despite extensive studies, the disease has not been shown to be associated with any preventable risk factors. Considering the differences in prostate-specific antigen (PSA) detection rates in different populations could help find a correlation. Compounds of arsenic and cadmium, anabolic steroids and ionizing radiation may be etiologic factors; carrots and soy may reduce the risk, 2. Is PSA testing an effective means of screening for prostate cancer? PSA (prostate-specific antigen) is a prostate-specific antigen, the total PSA value in normal human serum is <4.0ng/mL (Abbott AxSYM), if 10.0ng/mL then prostate cancer is very likely. 4.0 to 10.0ng/mL is mostly prostate hypertrophy, PSA will also be elevated in prostatitis. If the total PSA is between 4.0 and 10.0 ng/ml, measuring free PSA can help predict the likelihood of prostate cancer. Measurement of PSA levels in the blood is often used to detect prostate cancer. Without a reliable test, in some cases, by the time the earliest symptoms of cancer appear, it has metastasized to the bone and is then almost incurable. In the 1990s, diagnosis rates in the United States skyrocketed, in part because of PSA screening for asymptomatic men. There are many people who undergo unnecessary cancer treatment, but this is likely to do no harm. PSA testing would be a useful procedure if evidence-based guidelines were used. Combining this screening with other methods, such as screening for genetic markers, may reduce unnecessary treatment. 3. Should low-risk prostate cancer be removed? The most common treatments for limited disease - prostatectomy and radiation therapy - can have side effects, such as urinary incontinence and sexual dysfunction. Less aggressive tumors are best treated by avoiding these treatments. Between 2010 and 2013, half of all patients with low-risk prostate cancer in the United States underwent prostatectomy, while 40 percent chose to wait and see. Some studies have shown that low-risk patients can safely survive for more than 10 years with close monitoring. The challenge with active surveillance is to know who has slow-growing tumors that can be left unresected and who is more aggressive. New methods of distinguishing between aggressive and inert cancer cells are being investigated. 4. How to prolong survival in advanced prostate cancer? Once prostate cancer has spread to the lymph nodes and bones, the treatment outlook is poor. The 5-year survival rate for metastatic cancer is 1/3 that of limited cancer, and advanced prostate cancer is considered incurable. Treatments for advanced prostate cancer have only become available in the last 10 years. The treatment of choice is chemical castration: a drug to suppress androgens. This can extend life by 2 to 3 years before the tumor becomes resistant to the drug. Drugs to treat denuded resistant tumors also face great difficulty, with 20 to 40 percent of patients not responding to these treatments and eventually losing efficacy in all.