(CNN) Prostate cancer, one of the deadliest forms of cancer for men in the United States and worldwide, is on the decline, according to new research.

Researchers looked at World Health Organization data from five continents from 1980 to 2012 and saw an encouraging trend. In most parts of the world, the rate of men diagnosed with and dying of prostate cancer decreased or stabilized, according to the study, presented Tuesday at the American Association of Cancer Research meeting in Atlanta.

A walnut-shaped gland under the bladder, the prostate secretes seminal fluid, which provides nutrition for and allows the transport of sperm.

Dr. Alex Krist, vice chairman of the US Preventive Services Task Force and professor of family medicine and population health at Virginia Commonwealth University, who was not involved in the study, explained that prostate cancer "is one of the most common cancers that affects men. Usually, prostate cancer grows slowly."

The survival rate of patients with prostate cancer depends on factors such as how far it has spread.

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