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The glandular cells of the prostate play an important role in reproduction, producing the fluids that help make up semen. These tiny cells also serve as the birthplace for nearly all prostate cancers. Genes in these cells slowly mutate, leading to the formation of abnormal cells. The cells proliferate and cluster into tumors, thus giving rise to prostate cancer. But exactly what sparks this process and what causes prostate cancer remain elusive.
Scientists, however, continue to piece together the mosaic of genetic and lifestyle factors that seem to play a role in prostate cancer’s development. Their efforts are identifying not only whether your genetic code may place you at higher risk for the disease, but also potential avenues for how to avoid prostate cancer.
What Causes Prostate Cancer: Genetic Contributors
As with many cancers, the answer to the question of what causes prostate cancer lies partly in genetics. Prostate cancer appears to develop along a number of molecular and genetic pathways. Although having a genetic predisposition to prostate cancer doesn’t necessarily guarantee that you’ll get the disease, it does increase the likelihood.
A family history of prostate cancer—e.g., your father or brother had the disease—more than doubles the odds that you’ll develop the disease, too. Your risk may be even greater if you’ve had several family members who’ve had prostate cancer, especially if they were younger when they developed the disease.
You might inherit an increased risk of prostate cancer not only from your male relatives, but also from your female ones. If a woman in your family developed breast cancer caused by mutations in the BRCA1 and BRCA2 genes, you may face a greater risk of prostate cancer. Additionally, some evidence suggests that men with BRCA-related prostate cancers, especially those tied to BRCA2, are more likely to present with more advanced and aggressive disease, and they also may have worse survival outcomes after prostate cancer surgery.
Another inherited genetic abnormality, Lynch syndrome, which increases the risk of colorectal cancer and other cancers, also may be linked to a greater likelihood of developing prostate cancer. (Keep in mind, though, that these inherited genetic disorders account for a relatively minute percentage of prostate cancers.)
Genetics also may explain, at least in part, racial differences in prostate cancer risk. Prostate cancer occurs more commonly in African-American men and less so in Asian-American and Hispanic men. Rates of fatal prostate cancer also are significantly higher among African-Americans. However, exactly what causes prostate cancer to be more common and deadly in African-Americans and less common in other racial groups remains unclear.
How Your Lifestyle May Influence Your Risk
In their ongoing search for what causes prostate cancer, researchers have raised suspicions that certain modifiable factors may raise prostate cancer risk, increase the odds of having more aggressive disease, and worsen your overall prognosis.
Studies suggest that being obese is associated with a greater likelihood of high-grade prostate cancer and death from the disease, as well as poorer outcomes after prostate cancer treatment. One potential reason for this finding is that obese men tend to have larger prostates, and since it’s more difficult to find cancer in a larger prostate, these men may be more likely to have their cancer identified at a later stage.
Also, men who are obese have, on average, lower levels of prostate-specific antigen (PSA) found in the blood test used to screen for prostate cancer. As a result they may be less likely to have a potentially dangerous prostate cancer diagnosed early on.
Obesity has been tied to chronic inflammation, the body’s response to infection or injury. Fat cells in the abdomen produce an array of inflammatory substances, including insulin-like growth factor, which has been associated with prostate cancer growth. Scientists have found pockets of inflammation in cancerous prostate cells, leading them to theorize that inflammation caused by an infection and/or dietary and hereditary factors may contribute to gene alterations that cause prostate cancer.
Evidence suggests a potential role of diet in prostate cancer, but exactly how your eating habits affect your risk of the disease remains unclear. Researchers have yet to prove conclusively if any individual food or food group causes or prevents the disease. Rather, your overall dietary pattern seems to influence your prostate cancer risk.
How to Reduce Your Risk of Prostate Cancer
Many experts consider a heart-healthy eating plan—rich in fruits, vegetables, whole grains, and healthful protein and fat sources, and low in saturated fat, added sugars, sodium, and processed foods—to be beneficial for prostate health, as well. For example, rates of prostate cancer are lower in Asia, but when Asians immigrate to the United States and other countries that follow a typical Western-style diet, their risk of the disease increases.
One study (Cancer Prevention Research, June 2015) found that men who adhered to a Western-style diet (abundant in red and processed meats, high-fat dairy, and refined grains) were nearly three times more likely than those who ate a more heart-healthy diet to die from prostate cancer.
Still, researchers are unsure whether the increased risk of prostate cancer is a result of consuming these unhealthy foods or the fact that people who follow a Western-style diet tend to eat fewer fruits, vegetables, and other foods containing nutrients that may protect against prostate cancer.
Some research suggests that other factors may be on the list of what causes prostate cancer or results in poorer outcomes from the disease, but further studies are necessary to confirm these associations:
- Smoking: Research generally does not support a link between smoking and developing prostate cancer, but some studies suggest that smoking may increase the likelihood of dying from prostate cancer or experiencing a return of the disease.
- Sleep problems: One study found that men who had problems falling asleep or staying asleep were more likely to develop prostate cancer. One possible connection between sleep and prostate cancer is the hormone melatonin, which plays a key role in the sleep-wake cycle. Sleep problems can reduce melatonin production. In one study (European Urology, February 2015), researchers reported that men with sleep problems generally had lower melatonin levels in the morning, and below-average melatonin levels were associated with a greater risk of advanced prostate cancer.
- Vasectomy: Some research suggests that this common contraceptive surgery may increase the risk of high-grade or lethal/metastatic prostate cancer, but other investigations have not supported this association.
Originally published in 2016, this post is regularly updated.