BY MIKE STOBBE

AP MEDICAL WRITER

ATLANTA (AP) — The American Cancer Society is warning more explicitly than ever that regular testing for prostate cancer is of questionable value, and can do men more harm than good.

Two big studies last year suggested prostate cancer screening doesn’t necessarily save lives, and any benefits can come at a high price. The widely used PSA test often spots cancers too slow-growing to be deadly. It can yield false-positive readings that result in unnecessary biopsies. And it can lead to treatments that can cause impotence and incontinence.

But some doctors and advocates are troubled by the new guidelines.

“Prostate cancer is still something to be respected if not feared, and we still need to be vigilant,” said Dr. David Roberts, medical director of an Atlanta clinic. “I hope primary care docs or insurance companies don’t use the ‘softening’ of the guidelines as an excuse to not do screening at all.”

Dr. Stephen Freedland, an associate professor of urology at Duke University Medical Center, warned that the medical establishment seems to be moving backward on cancer screening.

“We have seen dramatic drops in mortality from breast, prostate and cervical (cancer) at a time when screening has been increasing, and now we are stepping off the pedal,” he said. “I don’t think that is the right answer.”

The cancer society’s new guidance released March 3 urges doctors to:

• Discuss the pros and cons of testing with patients, offering written information or videos that discuss the likelihood of false test results and the side effects of treatment.

• Stop routinely giving the rectal exam because it has not clearly shown a benefit, though it can remain an option.            

• Use past PSA readings to determine how often follow-up tests are needed and to guide conversations about treatment.

Prostate cancer screening became a medical mantra in the 1990s, thanks to the development of the PSA test.

For American men, prostate cancer is the second-deadliest cancer after lung cancer. An estimated 192,000 new cases and 27,000 deaths from it occurred last year in the United States.

But it is often a slow-growing cancer.

Another problem with the PSA test is that an elevated or fast-rising PSA reading can indicate the presence of cancer, but can also be caused by something minor, such as an infection or an enlarged prostate. A biopsy is needed to confirm cancer, and that can cause unnecessary pain and fear.

The new recommendations could be “game changers” in two respects, said Dr. John Davis, a urologist who directs prostate cancer screening for the University of Texas M.D. Anderson Cancer Center in Houston.

First, it may mean many doctors will stop routinely giving the PSA test, he said. About 41 percent of men 50 and older get annual prostate cancer screenings, he said. Second, the guidelines could have a chilling effect on community screening clinics in which hundreds of men line up and get free, quick exams, Davis said.

That was the intent, said Dr. Andrew Wolf, a University of Virginia physician who led the group that wrote the new guidelines.

Last year, the American Urological Association — a longtime proponent of regular prostate screening — backed off its call for annual tests after age 50.

The group said men should be offered a baseline test at 40, with follow-ups based on each man’s situation. The group also has stood by the rectal exam as a standard part of screening, saying it can find cancer that the blood test does not.

Men at higher risk, including blacks and men with a father or brother who had prostate cancer before age 65, should get the information beginning at 45.

Early prostate cancer has no symptoms.

Advanced disease may interfere with urination or cause blood in the urine. There are few good treatments for very advanced cases, though researchers reported March 3 that an experimental drug extended survival by 10 weeks. They were hopeful that the drug, cabazitaxel, might be more effective in stopping earlier cancers.

Associated Press Writer Stephanie Nano in New York contributed to this report.