Prostate cancer: Are you at risk?
Worldwide, prostate cancer is the second most common cancer and sixth leading cause of cancer death among men. The global lifetime risk of developing prostate cancer is estimated to be 7.15%, with an estimated 1.6 million men receiving a new diagnosis of prostate cancer in 2015.
The causes of prostate cancer are poorly understood, however there are certain factors known to increase an individual’s risk. These are primarily related to age and genetics. Other less well-supported risk factors include obesity, diet and sexual factors.
Prostate cancer is very rare prior to the age of 40, with the risk increasing sharply after the age of 50. Studies have found that 30% of males in their 50s and 80% of males in their 70s have some form of prostate cancer, even if it is just a small focus of cancerous cells. The average age of prostate cancer diagnosis is at 70 years.
Men with a family history of prostate cancer have an increased risk of being diagnosed themselves. Having a first degree relative, that is a brother or father, with prostate cancer, is associated with double the risk, and having two first-degree relatives increases the risk fivefold, as compared with an individual with no family history.
In addition, there is evidence that certain racial backgrounds carry an increased risk of prostate cancer. In the United States, increased rates of prostate cancer have been observed in black men as compared to white or Hispanic men.
Several genes have also been implicated in prostate cancer risk. The BRAC1 and BRAC2 genes increase a women’s risk for breast and ovarian cancer, and mutations in these genes have also been found to increase a man’s risk for prostate cancer. Other gene mutations found to adversely affect a man’s risk include the Hereditary Prostate Cancer Gene 1 and the androgen and Vitamin D receptor genes.
Being overweight or obese has been associated with an increased risk of being diagnosed with advanced (late-stage) prostate cancer rather than an increased overall likelihood of prostate cancer development. Reasons for this are unclear but may be related to hormonal factors in those who are overweight or perhaps that excess body weight makes the diagnosis of prostate cancer technically more difficult.
Several studies have found that higher meat consumption is linked to an increased risk of prostate cancer. Other dietary factors, such as poor intake of fruit and vegetables and excess consumption of processed meat and red meat, have also been suggested to contribute to a higher risk, although there is little evidence to back this up.
In addition, low levels of Vitamin D appear to increase prostate cancer risk, as does cadmium which is found in cigarette smoke and some food sources, while folic acid supplements seem to have little effect.
Studies have shown that having multiple sexual partners or becoming sexually active early in life significantly increases the risk of prostate cancer. In addition, multiple sexually transmitted diseases (STDs) have been associated with prostate cancer including gonorrhea, chlamydia or syphilis.
The take home message on risk
The strongest predictors of prostate cancer risk are those of age and genetics, both of which we have little control over. It is possible that maintaining a healthy weight, consuming less meat, ensuring adequate sunlight exposure and decreasing your risk of STDs, will decrease your chances of developing prostate cancer.
As a male, the most important way to reduce your risk is to undergo appropriate screening, so prostate cancer can be detected at an early stage, and give you the best chance of long-term health and survival.