The United States, Canada, countries of Western Europe (excluding Italy and Greece) and Australia are the countries with the highest incidence, prevalence, and mortality rates of prostate cancer in the world. These countries are
considered high-risk countries. Countries in Asia, particularly
Japan, are considered low-risk countries. Researchers
attribute prostate cancer risk based on location to
three factors: UV light, testing prevalence, and traditional
UV Light and Prostate Cancer
Some researchers believe that insufficient exposure
to UV rays may lead to higher risks of prostate cancer
and higher prostate cancer mortality rates. Countries
within high latitudes such as Canada and Sweden have
the highest prostate cancer mortality rates in the world.
Black men living in America also have uncharacteristically
high rates of aggressive prostate cancer and prostate
UV light stimulates the production
of Vitamin D, which some researchers believe provides
a protective effect when present in adequate (not excessive)
quantities. The lower levels of UV ray exposure in high-latitude
countries may not provide the sufficient exposure its
inhabitants require. African-American men may not receive sufficient UV exposure due to increased levels of skin melanin which block UV rays.
PSA Testing and Prostate
Some doctors believe that all men, if given enough time,
will eventually develop prostate cancer. Some countries,
particularly the United States, place a high emphasis
on testing. Therefore, the countries that advertise the importance of yearly prostate specific antigen (PSA) tests and digital rectal exams (DRE’s) beginning at ages 40 through 50, are much more likely to have higher rates of prostate cancer within their geographic area due to increased disease identification.
Countries that do not place a high
emphasis on testing may have prostate cancer deaths
that go unrecorded. Because most cases of prostatic adenocarcinoma,—the most common type of prostate cancer—grow very slowly, many men may die with prostate cancer but not because of it. High-risk countries, such as America, tend to place emphasis on early testing, which may inflate their rate of incidence.
Traditional Diet and Prostate
Asian men seem to have the lowest chances of developing
prostate cancer. Japan has the lowest rates in world.
Some researchers attribute these numbers to the traditional
rural Japanese diet which is based on fish rather than
red meat. Supporting this theory are the rising levels of the disease which coincide with the westernization of the Japanese diet. Additionally, Asian men who immigrate
to the United States have incidence rates similar to
the majority population.
European men from countries with
relatively low rates of the disease, in part due to
traditional diet which focuses on olive oil and vegetables,
also begin to display higher levels of prostate cancer
after immigrating to the Unites States. Click here to
read more about Prostate
Cancer Risk and Diet.
Other factors, such as pollution, may increase chances for the disease, but at this time, no conclusive studies exist that corroborate these location factors.