The prostate gland. Credit: nih.gov

TUESDAY AUGUST 6 (foodconsumer.org) -- U.S. Preventive Services Task Force on August 5 updated its recommendations to suggest that doctors should not do screening of prostate cancer in men aged 75 or older because evidence is sufficient that the  test would do more harm than good for the elderly in this age group.

The voluntary panel, which is supported by the U.S. government as mandated by U.S. Congress, but does not represent the government, also said that the benefits of prostate cancer screening for men younger than 75 remain unknown.

 The USPSTF updated its 2002 recommendation about screening for prostate cancer and published a statement in the August 5 2008 issue of Annals of Internal Medicine.

The new recommendations were based on a review of randomized, controlled trials of the benefits or prostate cancer screening, cohort and cross-sectional studies of the psychological harms of the false-positive prostate-specific antigen (PSA) test results among other evidence.

The group said in its statement that evidence is convincing that PSA screening can detect SOME cases of prostate cancer, but evidence is also convincing that treatment for prostate cancer detected by the screening causes moderate-to-substantial harms in men including erectile dysfunction, urinary incontinence, bowel dysfunction and even death.

For some men, the PSA screening is never justified because they would otherwise have never developed symptoms related to prostate cancer during their lifetime.

There is adequate evidence that the screening process at least produces small harms such as pain and discomfort associated with prostate biopsy and psychological effects of false-positive test results. The method is not a protocol to confirm prostate cancer. Confirmation of this disease needs to be done by a biopsy.

Many men with a high reading of PSA, that is, above 4.0 ug/L, are diagnosed with prostate cancer. But some cases are missed by this cut-point.   The test also results in some false positive cases in which the men would suffer an unnecessary biopsy.

The task force said if there is any benefit, then men aged between 50 and 74 inclusive may benefit most from the screening.

But even if the prostate cancer screening is effective, a 75 year-old man is not expected to experience the benefit because it would take more than 10 years to experience a mortality benefit while the average life expectancy for the man is about 10 years. This means very few men age 75 years or older would have any benefit from the test.

Likewise, men who are younger than 75, but have chronic medical conditions and expected to live fewer than 10 years are unlikely to benefit from the prostate cancer screening and treatment.

The conclusion of the review is not conclusive, according to the panelists. They hope that two ongoing trials, the U.S. Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and the European Study of Screening for Prostate Cancer, may help shed light on the potential benefits of the screening.

Prostate cancer is diagnosed in 210,000 men and kills about 27,000 each year in the United States, according to the National Cancer Institute.   About 71 percent of deaths occur in men older than 75 years according to the task force's statement.

PSA screening test results in over-diagnosis rates ranging from 29 percent to 44 percent of all prostate cancer cases.

The problem with the test is the accuracy of the test, effectiveness of early detection and treatment, and estimate of magnitude of net benefit from the screening.