The bad news is that prostate cancer rates are on the rise, making it the biggest health concern for men over 50. The good news? Experts are getting a better handle on the causes and treatments for the disease.

Prostate cancer is a malignancy that develops in the prostate gland, which maintains the proper function of the male reproductive tract.

There will be about 198,100 new cases the United States this year and about 31,500 men will die of the disease, according to the American Cancer Society.

Prostate cancer is the second leading cause of cancer death in men, exceeded only by lung cancer.

Turned 40? Get Tested

Men should get tested for prostate cancer starting at age 40, prostate cancer expert Dr. Patrick C. Walsh told Good Morning America .

"I've operated on 750 men under 55, so I believe testing should begin earlier, at 40," said Walsh, a urology professor at the Johns Hopkins Medical Institutions who is thought by many to be the world's foremost authority on prostate cancer.

A man should particularly make sure to get the test at 40 if prostate cancer runs in his family -- his chances of developing prostate cancer are two times greater if the patient has a father or brother with the disease.

Age is also a big factor: Three quarters of all reported cases occur in men age 65 and older.

As recommended by the Journal of the American Medical Association , men should get their first test at age 40, their second at 45 and the third at 50, Walsh said.

The safest type of screening involves both a Prostate Specific Antigen and a rectal exam, since 25 percent of men who have cancer will have a low PSA.

If the PSA test and/or rectal exam have caused the doctor concern, biopsies are needed, Walsh said.

"We don't know how to prevent it, but we know how to test for it, and treat it," he says. "It's not something to play around with."

Not every irregularity is cancer. It could be a benign prostatic hyperplasia, which is an enlarged prostate, or prostatitis, an inflammation. Both are infections that are highly treatable.

Race and Diet Factors

Race can also be factor in a man's likelihood of developing prostate cancer. African-American men have the highest incidence of prostate cancer in the world, while Asian men have the lowest risk.

Although doctors do not know for certain why some races have higher rates, diet may play a role, since Asians who move to the United States and adopt a Western diet have higher rates than their counterparts in Asia.

For African-American men, the higher rates could be attributed their dark skin color, which does not soak up as much Vitamin D from the sun, leading to a deficiency, Walsh says.

Other experts believe that it may be due to health-care differences. Swedish men, for instance, have a high rate of death due to prostate cancer because there is virtually no screening in their country.

In any case, Walsh recommends an Asian diet: "The low rates of prostate cancer in Asia is reason enough to make some dietary changes," Walsh says. "I recommend a diet low in red meat and dairy, and rich with fruits, vegetables, soy and antioxidants."

Treatment Depends on Lifestyle

As a general rule of thumb about age and treatment, many doctors say that a man in his 50s should have surgery, in his 60s should have radiation, and in his 70s should manage the cancer rather than treat it.

But Walsh says each man is different, and lifestyle is more important.

"I tell my patients to think of the worst-case scenario of the treatment, rather than the best," he says. "If the worst happened, could they live with the side effects of the treatment?"

Radical surgery is the best chance of eradicating cancer, but there is a risk of impotency and incontinence. For some men in their 50s, that's an acceptable risk, but for sexually active men, radiation might be preferable. Men over 70 might not want to deal with the cancer, as the treatment might be more intrusive than the disease.

Impotency, the worst-case scenario for many men, is relatively equal with any of the treatments, Walsh said. The prostate is not required for fertility or potency, but men who undergo treatment for prostate cancer should be prepared to lose their ability to have an erection.

Running along each side of the prostate is a nerve bundle responsible for erection. Impotence, the loss of sexual function, may occur as a result of damage to these nerves either from surgery or radiation therapy. Over time, potency may return and Viagra can help.

In the future, Walsh says he expects to see new hormonal treatments, along with more research into diet and into the molecular mechanics of cancer cells.

Families coping with prostate cancer should make sure they take care of themselves and not get exhausted, because the patient will need them throughout the process, he said.

From ABCNews.go.com