Warren Buffett, chief executive of Berkshire Hathaway Inc. and the third-richest man in the world, revealed on April 17 he has prostate cancer. Buffett is one of about 240,000 men who will be diagnosed with prostate cancer in the United States this year.


Here are five things you should know about prostate cancer.


Disease of old age

Prostate cancer is most common among men over age 65, and is rarely found in men under age 40, according to the National Institutes of Health. It is the second most common cancer in men, after skin cancer, according to the Centers for Disease Control and Prevention.


Autopsy studies show as many as 75 percent of men over age 85 had prostate cancer when they died, though the disease was not necessarily lethal, according to the U.S. Preventative Services Task Force.


Many prostate cancers are slow growing and will not affect a man's health or life, because men die from other causes before the cancer kills them, the task force says.


Screening is controversial

Doctors can screen for prostate cancer using the prostate-specific antigen (PSA) blood test, but its use in healthy men without symptoms remains controversial. Last year, the task force recommended against routine prostate cancer screening in healthy men, saying that for those ages 50 to 69, the benefit of screening was small to none.


Studies on the topic also have conflicting results. A recent study of 76,000 men ages 55 to 74 in the United States found men who underwent yearly screening for prostate cancer were just as likely to die from the disease as those who underwent screening only if their doctor recommended it. On the other hand, a European study published last month found prostate cancer screening does save lives, but may need to be carried out for more than 10 years to have a benefit.


The American Cancer Society recommends men discuss with their doctor the pros and cons of PSA screening to make a decision about whether testing is right for them.


Overdiagnosis a problem

A major concern with PSA testing is that it finds cancers that would never have been diagnosed otherwise, meaning the cancers would not have gone on to cause significant health problems for patients. In the recent European study, about half of cancers detected by PSA tests fell into this category.


Such overdiagnosis is a problem because men may receive tests and treatment they do not need. Side effects of prostate cancer treatment include erectile dysfunction and loss of urinary control.


Monitoring rather than treating

Currently, about 10 percent of men diagnosed with prostate cancer delay treatment, while the remaining 90 percent receive treatments such as surgery or radiation therapy, according to the National Institutes of Health.


However, about 40 percent of men diagnosed each year, or 100,000 men in the United States, could delay treatment with a strategy called active surveillance, according to a recent NIH panel. Under active surveillance, patients with low-risk prostate cancer receive regular follow-up testing and are treated only if the cancer becomes more aggressive.


Many experts believe active surveillance is a way to reduce the harms of screening.


Reducing risks

One way to reduce prostate cancer risk is with diet. Studies show vegetarians have a lower risk of prostate cancer than men who eat meat, according to the National Institutes of Health. A nutrient called lycopene, found in tomatoes, has been consistently linked with lower prostate cancer risk, according to the Mayo Clinic. Evidence also suggests that vitamin D may lower men's risk of developing a deadly form of prostate cancer.


Exercise to maintain a healthy weight can also reduce your risk, the Mayo Clinic says. Obesity has been shown to increase the risk of aggressive prostate cancer.


Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @RachaelRettner. Find us on Facebook.


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