Risk factors for prostate cancer
A risk factor is something that increases the risk of developing cancer. It could be a behaviour, substance or condition. Most cancers are the result of many risk factors. But sometimes prostate cancer develops in men who don’t have any of the risk factors described below.
The risk of prostate cancer increases as men grow older. The chance of being diagnosed with prostate cancer increases after age 50. Prostate cancer is diagnosed most often in men in their 60s.
Prostate cancer occurs in men of African ancestry more often than men of other ethnicities. Men of African ancestry are also more likely to die of prostate cancer compared to other men. The reason for this is not clear.
Family history of prostate cancer
There is convincing evidence that having a family history of prostate cancer increases your risk of developing the disease. This risk is higher if a first-degree relative (your father, brother or son) has been diagnosed with the disease. The more first-degree relatives with prostate cancer a man has, the greater his risk of developing prostate cancer.
Prostate cancer risk also depends on your relative’s age at diagnosis. If your relative was diagnosed with prostate cancer before the age of 65, your chance of developing prostate cancer is higher than if your relative was diagnosed at an older age.
Possible risk factors
The following factors have been linked with prostate cancer, but there is not enough evidence to show for sure that they are risk factors. More research is needed to clarify the role of these factors for prostate cancer.
Obesity or overweight
Studies show that obesity or overweight increases the risk for prostate cancer and it is more likely to be diagnosed at an advanced stage. High body fat has also been linked with a higher risk of developing high-grade prostate cancer.
Tall adult height
There is evidence that being a tall adult man probably increases the risk of prostate cancer. Several factors that lead to tall adult height, such as genetics and rate of growth during childhood, seem to contribute to the greater risk.
Diets high in dairy products and calcium
There is some evidence that diets high in dairy products and calcium may increase the risk of prostate cancer. Milk, yogurt and cheese are examples of dairy products and are also foods high in calcium.
Low blood levels of vitamin E or selenium
Some research shows that men who have low levels of vitamin E or selenium in their blood may have a higher risk of developing prostate cancer. But there is not enough research on increasing amounts of vitamin E or selenium through diet or supplements to lower the risk for prostate cancer.
Inherited gene mutations
Studies show that some inherited gene mutations (changes) may increase the chance of developing prostate cancer. Only a very small number of cases of prostate cancer are linked with inherited gene mutations.
Two gene mutations related to prostate cancer are HOXB13 and BRCA2. (The BRCA2 gene mutation also increases a woman’s risk of developing breast or ovarian cancer.) Researchers are studying other gene mutations that may affect the risk of developing prostate cancer.
Find out more about genes and cancer.
Smoking tobacco may increase the risk for prostate cancer. Some studies also show that smoking may increase the risk of being diagnosed with fast-growing (aggressive) or advanced prostate cancer. It is unclear whether smoking affects incidence or prognosis or both.
High levels of androgens
Androgens are male sex hormones that control the growth, development and function of the male reproductive system, which includes the prostate. Testosterone is the main androgen. It is naturally found in the body. It can also be taken as a treatment (called testosterone therapy) for certain conditions.
Some evidence suggests that high levels of androgens in the body are related to the development and growth of prostate cancer. More research is needed to understand the long-term effects of having high androgen levels and taking testosterone therapy.
Inflammation of the prostate
Inflammation of the prostate is called prostatitis. Many studies show that long-term inflammation of the prostate increases the risk of developing prostate cancer. It also makes prostate cancer grow and spread more quickly.
Find out more about prostatitis.
Working with certain chemicals
Some evidence suggests that contact with the following chemicals may increase the risk for prostate cancer.
Pesticides used in agriculture jobs are linked with a higher risk for prostate cancer. The risk may be even higher for men with a family history of prostate cancer. Researchers don’t know how much exposure to pesticides and which specific chemicals affect prostate cancer risk.
Cadmium is a metal known to cause cancer (called a carcinogen). Some studies show that men who have contact with cadmium in smelting or battery manufacturing industries have a higher risk of developing prostate cancer. Not all research has shown this increased risk.
Chemicals in rubber manufacturing may increase the risk for prostate cancer.
No link to prostate cancer
Significant evidence shows no link between benign prostatic hyperplasia (BPH) and a higher risk for prostate cancer.
Research also shows that eating foods or taking supplements containing beta carotene (a type of carotenoid) is unlikely to affect the risk for prostate cancer.
Questions to ask your healthcare team
To make the decisions that are right for you, ask your healthcare team questions about risks.
A condition in which a person has an abnormally high, unhealthy amount of body fat.
Obesity increases the risk of several types of cancer, including breast, uterine, pancreatic, kidney, colorectal and liver.
Extra body fat that may have a harmful effect on health. Overweight increases the risk of gallbladder, kidney, uterine, colorectal, esophageal and other cancers.
A body mass index (BMI) of 25 to 29.9 is generally considered to be overweight.
A description of the extent of cancer in the body, including the size of the tumour, whether there are cancer cells in the lymph nodes and whether the disease has spread from its original site to other parts of the body.
Stages are based on specific criteria for each type of cancer.
The process of determining the extent of cancer in the body based on exams and tests is called staging.
Referring to or having to do with cancer cells that do not look or act like normal cells (undifferentiated) and tumours that tend to grow and spread quickly.
A mineral that the body uses to build and maintain bones, teeth and connective tissues (tissue that surrounds and supports various organs in the body), and is essential in metabolism and the functioning of nerves and muscles.
Calcium is found in dairy products, leafy green vegetables, seeds and nuts, tofu and dried fruit.
Calcium is a type of electrolyte.
A mineral that the body needs for normal cell function and that has antioxidant effects.
Selenium is found in kidney, liver, rice and grain products (such as wheat germ), Brazil nuts and some fish.
Passed from parent to child through information contained in genes.
Also referred to as hereditary.
The total number of new cases of a disease diagnosed in a given population during a specific period of time.
Incidence rates are typically reported as the number of new cases for every 100,000 people per year.
The expected outcome or course of a disease.
The chance of recovery or recurrence.
The group of organs and glands involved with sexual reproduction (having children, or offspring).
In women, the reproductive system includes the ovaries, fallopian tubes, uterus (womb), cervix and vagina. The ovaries make eggs (called ova). The ovaries also make the hormones estrogen and progesterone.
In men, it includes the testicles, prostate and penis. The testicles make sperm. The testicles also make the hormone testosterone.
A yellow, orange or red substance found mostly in plants, including yellow and orange fruits and vegetables (such as carrots and sweet potatoes), as well as in dark green, leafy vegetables (such as spinach and kale) and some grains. The body changes some carotenoids into vitamin A.
Carotenoids include beta carotene, lutein and lycopene.
Carotenoids are a type of phytochemical that have antioxidant effects. Researchers are studying the role of carotenoids in preventing cancer.
Cancer affects all Canadians
Nearly 1 in 2 Canadians is expected to be diagnosed with cancer in their lifetime.