September 1, 2009

Prostate Cancer Screenings Not Always Beneficial

Since becoming a routine part of men's health exams, prostate cancer screening has successfully diagnosed more than 1 million US men with tumors that may have been fine if left untreated, according to new research.

Advanced prostate cancer screening, known as the prostate-specific antigen (PSA) test, has allowed doctors to see tumors in very early stages, but "it has also resulted in the diagnosis of cancers that are so small they pose no near-term danger and possibly no long-term danger," said study co-author Martin Sanda, a professor at Harvard University.

Researchers estimated that about 1.3 million people in the US have been diagnosed with prostate cancer since the introduction of PSA testing.

"That is a huge effect," Dr. H. Gilbert Welch of the VA Outcomes Group in White River Junction, Vermont, whose study appears in the Journal of the National Cancer Institute, told Reuters.

Researchers noted that more than 1 million of those men were treated for prostate cancer.

"These are men who could not be helped by treatment because their cancer was not destined to cause them symptoms or death," said Welch.

He added that about 20 men had to be diagnosed and treated for every one who benefited.

Sanda's team studied 51,529 men beginning in 1986. The men were asked to fill out health surveys every two years.

Researchers found that 3,331 men said they had been diagnosed with prostate cancer between 1986 and 2007.

Of those men, 342 opted out of treatment for at least one year, and 10 to 15 years later, half of those diagnosed had not been treated at all.

Sanda and colleagues noted that deaths caused by prostate cancer "were very low among the men with low-risk tumors."

Sanda said that a standard treatment for low-risk cancers "might help us avoid throwing the baby out with the bath water when it comes to the PSA test."

"This would avoid problems due to treatment of 'overdiagnosed' low-risk cancers, while preserving the life-saving benefits of treating aggressive cancers that have been detected through PSA testing."


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