A risk factor is anything that impacts a person’s chances of contracting a particular disease. Risk factors can be divided into two groups, those that can’t be controlled or changed, like family history, genetic makeup, and age, and those that can be, like smoking, obesity, diet, excessive use of alcohol, and exposure to particular drugs or radiation.
Several risk factors have been linked to prostate cancer, and may change one’s risk of getting it. These risk factors are nationality, genes, diet, age, family history, and race/ethnicity. Other risk factors that are thought to affect one’s risk of getting prostate cancer but are still under study include exercise, obesity, vasectomy, infection and inflammation of the prostate.
Nationality has a bearing on the incidence of prostate cancer with North America having the highest rate of the disease, followed by Australia, northwestern Europe and the Caribbean islands. Lower rates are reported for Africa, Asia, Central America and South America, which may be partially due to lower screening in some of these countries. Lifestyle differences such as diet may be responsible, as well. The lower rate of prostate cancer observed in Asian men may be due to diet, which consists of more vegetables and less red meat than in the United States. However, men of Asian descent living in the United States have a lower risk of prostate cancer than white Americans but a higher risk than Asians living in Asia. The reasons for different rates of prostate cancer in different countries are still unclear.
Several inherited genes seem to raise the risk of prostate cancer, but they most likely account for just a small number of cases. Recent studies have linked some gene variations to prostate cancer but further studies are necessary to confirm these results and determine if testing for the variants will help predict the risk of prostate cancer. Inherited mutations of the BRCA1 or BRCA2 genes have been linked to the incidence of breast and ovarian cancers in some families and may increase prostate cancer risk as well, but this genetic link also accounts for only a small number of prostate cancer cases.
One major risk factor for prostate cancer is age. It is rare for a man to contract prostate cancer before the age of 40, but his chances of contracting the disease rise dramatically after age 50. Nearly 2 out of 3 prostate cancers are diagnosed in men over 65 years of age.
Prostate cancer occurs more frequently in African-American men than in men of other races. In addition the cancer is more likely to be diagnosed at an advanced stage. The number of African Americans who die from prostate cancer is more than twice that of white men. Non-Hispanic whites have a higher incidence of prostate cancer than Asian-American or Hispanic-Latino men. Further study is necessary as the reasons for these racial and ethnic disparities are unclear.
Family history has a bearing on one’s risk of developing prostate cancer. Men who have a first degree relative (ie, brother or father) with prostate cancer have a greater risk of developing the disease. If a man has several affected relatives he has an even higher risk of developing prostate cancer.
Diet and exercise are thought to be linked to prostate cancer. A diet of high-fat dairy products and red meat seems to increase the risk of getting prostate cancer. However, men who have this type of diet also eat fewer vegetables and fruit, and scientists are unsure which of these factors is responsible for the increased risk. Studies on exercise have demonstrated no significant link between exercise and reduced risk of prostate cancer; however, some studies have shown that the risk of advanced prostate cancer may be lowered by high levels of physical activity, particularly in older men.
Other possible risk factors for prostate cancer include inflammation of the prostate, vasectomy and infection, but studies performed thus far have been inconclusive.