Although the causes of prostate cancer are not well understood at this time, research studies have identified several risk factors for prostate cancer.
Prostate cancer occurs more frequently in older men. Although prostate cancer has been discovered in men as early as in their 40s, it is most commonly diagnosed in men over the age of 65. In fact, more than 75% of men diagnosed with prostate cancer each year are over the age of 65.
Research suggests that prostate cancer may be more common in certain ethnic populations. For instance, studies have shown that prostate cancer is more common in men of African ancestry as compared to Caucasian men, while Asian and Aboriginal populations seem to have the lowest rates of prostate cancer.
Research studies have consistently shown an increased risk of developing prostate cancer in sons and brothers of men diagnosed with prostate cancer. In fact, for men with one close relative (for example, a brother or father) with prostate cancer, their risk to develop this condition is about twice that of a man with no family history of prostate cancer. This risk may be further increased, if more than one family member has been diagnosed with prostate cancer, or if prostate cancer was diagnosed at a young age (for example, less than 60 years of age).
Since each family is different, a genetic assessment of your family is necessary to determine your personal chance to develop prostate cancer. In addition, a genetic assessment can also determine whether your family may have a hereditary (inherited) type of prostate cancer or other hereditary cancer condition that is passed from generation to generation. For further information on hereditary prostate cancer or arranging a referral for a genetic assessment, please visit the hereditary risk factors section of our site.
Research has suggested that diet may act as a risk factor for the development of prostate cancer. Support for this association comes from research on Asian immigrant populations, in which within one generation an over three-fold increase in the number of these men diagnosed with prostate cancer was observed. This increase in the frequency of prostate cancer was primarily attributed to changes in diet upon immigration to North America.
In addition, a number of other studies investigating an association between diet and the risk to develop prostate cancer have shown that a high fat diet may increase a man’s risk of developing prostate cancer.
For further information about the role of dietary choices and dietary supplements in prostate cancer prevention, please see our diet section.
Hereditary prostate cancer refers to prostate cancer that appears to be “running” in a family. In these families, it is suspected that alterations in specific genes (instructions found in every cell of our body that tell our body how to grow and develop) passed from generation to generation may play an important role in the development of prostate cancer.
We may suspect that a family is at risk for hereditary prostate cancer if the following criteria are met:
- Three or more immediate family members (for example, father or brothers) diagnosed with prostate cancer, or;
- Prostate cancer in three generations on either side of the family (mother’s or father’s), or;
- Two family members diagnosed with prostate cancer at or before age 55.
It is estimated that about 5-10% of all cases may be classified as hereditary prostate cancer.
Could my family have an inherited form of cancer and not meet these criteria?
Yes, in some families that do not meet the criteria listed above, it still appears that cancer may be “running” in the family. For instance, in some cases there may be a family history of prostate cancer along with other cancers, such as breast or ovarian cancer, which can sometimes be associated with other types of hereditary cancer. Genetics professionals working in a cancer clinic can assess the likelihood of your family having an inherited or hereditary form of cancer.
If our family has a hereditary form of prostate cancer, what can we do about it?
It is important to remember that if your family appears to have a hereditary form of prostate cancer this does not mean that you will develop the cancer. It merely suggests that you may have an increased chance of developing prostate cancer compared to other people in the general population. Since each family is different, a genetic assessment of your family history is necessary to determine your personal chance to develop prostate cancer.
If an assessment reveals that you may have an increased chance of developing prostate cancer, you may wish to discuss surveillance options for prostate cancer with your doctor. Options include:
- rectal examination
- a blood test for prostate specific antigen (PSA)
In families with hereditary prostate cancer, some individuals may be offered surveillance for prostate cancer at an earlier age, in the hopes of earlier detection and treatment of cancer. You may also wish to discuss with your doctor the role of diet in cancer development and prevention.
If my family has hereditary prostate cancer, is genetic testing available?
Genetic testing would involve looking for alterations in a specific gene that is involved in hereditary cancer. In most cases, we are unable to offer genetic testing for prostate cancer because the genes involved have not yet been identified. As research is ongoing to try to identify these genes, genetic testing may be possible for some families in the future.
Other Factors and Risk Markers
A variety of other lifestyle and medical factors have also been investigated as potential risk factors or risk markers for developing prostate cancer. A few of these are described below:
Prostatic Intraepithelial Neoplasia (PIN)
PIN is a type of pre-cancerous cell growth that in some cases can develop into prostate cancer. PIN can be divided into two categories, low and high grade. High grade PIN may represent an intermediate stage between a benign growth and malignancy. Men diagnosed with PIN on prostate biopsy may be at an increased risk of developing prostate cancer in the future. For this reason, these men should be followed closely for the development of prostate cancer.
Elevated Prostate Specific Antigen (PSA) Blood Levels
The PSA test is a blood test that is used as a screening tool for prostate cancer. Having an elevated PSA level may serve as a risk marker for prostate cancer. To learn more about this test, go to the PSA section of this website.
Benign Prostatic Hyperplasia (BPH)
BPH is an abnormal growth of benign (non-cancerous) prostate cells. BPH causes the prostate to enlarge and is a common condition in men as they get older. At the present time, BPH is not thought to cause cancer or lead to an increased risk to develop prostate cancer. For further information on this topic, please refer to the diseases of the prostate section.
Conclusions regarding increased risk of developing prostate cancer due to smoking have been conflicting. More research is still needed to better understand if there is an association between smoking and someone’s risk to develop prostate cancer.
Similarly to smoking, conclusions about increased prostate cancer risk due to alcohol usage have been conflicting.
No occupation has been directly linked to developing prostate cancer.