Hematology/Oncology

The U.S. Preventive Services Task Force today issued a draft recommendation saying that healthy men do not need to be screened for prostate cancer, and discouraging the use of PSA screening. Previously the task force had previously taken the position that there was not enough evidence to determine the value of screening.

The recommendation applies only to symptom-free men regardless of age, race or family history. USPSTF did not evaluate the test as part of a diagnostic strategy in men with symptoms that are highly suspicious for prostate cancer.

The task force said the PSA test can have false positive results which lead to increased stress and unnecessary biopsies. Moreover, many men will be unnecessarily treated for prostate cancer based on PSA test results and that treatment is associated with side effects such as urinary incontinence and erectile dysfunction.

Previously the task force recommended against screening men older than 75 years, and said there was insufficient evidence to determine whether PSA screening had value for younger men.

Experts in the field have debated the issue for years. For every trial like the European Randomized Study of Screening for Prostate Cancer, which appeared to show a 20% relative reduction in disease-specific mortality after 9 years, there is a study like the PLCO Cancer Screening Trial which showed no mortality benefit associated with PSA screening. The task force recommendations reflect "the difficulty we've had in showing that PSA screening saves lives," said Donald L. Trump, MD, president and CEO of Roswell Park Cancer Institute and HemOnc Today section editor for genitourinary cancer.

"Given that difficulty, it's hard to recommend on solid scientific grounds that all men should have their PSA tested," he said. "On the other hand, there is no doubt PSA can find important prostate cancers. The key from my perspective is for clinicians to have the discussion about the pros and cons of measuring PSA and use it judiciously, not as a flawed screening procedure."

H. Ballentine Carter, MD, professor of urology and oncology at Johns Hopkins Medicine and director of adult urology at the James Buchanan Brady Urological Institute, called the new recommendations a "bombshell." There is no question that PSA screening saves lives, he said, but there are well-known benefits and drawbacks with the test.

"We can argue about the randomized trials and what they show and how well they were done, but I don't think it's necessary," he said. "There really is no other way to explain the 40% reduction in prostate cancer mortality in this country other than, for the most part, PSA screening."

The American Cancer Society estimates that roughly 240,000 men will be diagnosed with prostate cancer this year. Many of those men will never suffer any complications from the disease and may, in fact, be harmed by treating an indolent cancer. However, ACS also estimates that more than 33,000 men will die from prostate cancer in 2011, and there is no way to determine which cancers should be treated and which can be safely left alone.

ACS has taken a neutral position on screening, saying only that the patient has the right to make an informed choice. ACS recommends that most men should be informed about PSA screening at age 50, and that black men or others at increased risk should be informed about the test at a younger age.

The American Urological Association says that the decline in prostate cancer deaths from 1975 to 2005 can be attributed at least in part to the advent of PSA screening. Its recommendations, issued in 2007 and confirmed again this year, say that men should undergo PSA testing and digital rectal exam as early as age 40.

While Carter remains a supporter of PSA screening, he says the test is overused, and has long talked about the need for targeted screening and proper disease management. There is no point in screening men aged 75 or older whose PSA score is less than three, which represents two-thirds of older men, he said.

"We have level-one evidence that we don't need to screen everyone yearly to reduce mortality," he said. "We have level-one evidence to suggest that a large proportion of people could discontinue screening and they would never be harmed. And we have level-one evidence to suggest that there is a large group of people who don't need to be treated and could be monitored safely for 15 years, and probably more. But despite the fact that these ideas - targeted screening and active surveillance - are shovel-ready, we're not using them. I know it would be difficult in our medical system; that's what needs to happen."

Nicholas J. Vogelzang, MD, medical director for U.S. Oncology and a HemOnc Today Editorial Board member, said that there are no oncologists or urologist on the task force. He added that most men do not require annual screening, but the task force goes too far in issuing a blanket recommendation against screening.

"The natural history of prostate cancer has not been taken into account. This is a 20-year disease, not a 10-year disease. We have screening studies only from the mid-90s and they're not complete yet. What data we do have with long follow-up suggests that the number of patients with metastatic prostate cancer at diagnosis in United States has dropped from 35% or higher to the single digits. I would have just kept the guidelines as they currently are." - by Jason Harris

Disclosure: Drs. Carter, Trump and Vogelzang reported no relevant financial disclosures.

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