We don't know exactly why and how prostate cancer starts. Autopsy studies show that one in every three men over age 50 have signs of prostate cancer. Up to 80% had small, low grade tumors. A study of organ donors found prostate cancer in 1 in 3 men age 60–69 and in 46% of men over age 70.
What causes prostate cancer is still unknown. Research hopes to find the answer soon. Modern theory is that many things can raise a man's risk for prostate cancer.
What Are The Risk Factors for Prostate Cancer?
As men age, their risk of prostate cancer goes up. The American Cancer Society says prostate cancer causes about 10% of cancer–related deaths in men 60 to 79 years old. It causes nearly 25% of cancer deaths in men over age 80. It is rarely found in men younger than 40.
African–Americans are in the highest risk group. There are more than 200 cases per 100,000 black men. White and Asian men have about half as many cases as African-Americans. African–American men tend to be diagnosed when the disease is more advanced. They are more likely to die of prostate cancer than white or Asian men.
Men with a family history of prostate cancer also face higher risk. The more close relatives (father, son, brother) diagnosed with prostate cancer, the higher your risk. The age when a close relative was diagnosed can also raise your risk. If you have a family history, you are 2 to 11 times more at–risk than men with no family history.
If your father, brother or other close relative had prostate cancer, you are at higher risk. This is true if two or more close relatives had prostate cancer. It is also true if a close relative was diagnosed before age 55.
Studies show prostate cancer risk may double for heavy smokers. Within 10 years of quitting smoking, your risk goes down to that of a non–smoker the same age.
Prostate cancer numbers and deaths vary around the world. Numbers are low but rising in Asian countries. Numbers are medium in Central America and Western Africa. They are higher in North America and Northern Europe. The higher rates may be due to better screening, heredity, diet and environment.
The differences may also be linked to soy proteins in the diet. In some Asian countries, soy intake in tofu, soy milk, and miso is up to 90 times higher than in the U.S. Prostate cancer numbers and deaths are much lower in those countries. A study of more than 40 nations found soy, per calorie, to be the most protective dietary factor. This may be linked to chemicals in soy. They may act as weak estrogens. Estrogens are female hormones. They slow down prostate cancer growth. Some experts think high intake of green tea in Asia may also have an effect. But, there are no clear answers yet.
Diet and lifestyle may affect the risk of prostate cancer. It isn't clear exactly how. The risk may be higher for those who eat more calories, fat and refined sugar and not enough fruits, vegetables and exercise. Obesity is linked to increased risk for death from prostate cancer. One way to avoid death from prostate cancer is to lose weight, and keep it off.
Can Prostate Cancer Be Prevented?
There is no known way to prevent prostate cancer. But if you do things that are heart healthy, you will also keep your prostate healthy. Eating right, exercising, watching your weight, and not smoking can improve your health and help avoid prostate cancer.
There is still debate on how to prevent prostate cancer. Some health care providers believe drugs like finasteride (Proscar) and dutasteride (Avodart) can prevent it. Others believe they only slow progress. In studies, men taking these drugs were less likely to be diagnosed with prostate cancer. It is not known if the drugs slow the cancer and lower the death risk.