Medical thinking on prostate cancer screenings is about to change

The U.S. Preventive Services Task Force made news on April 1, with recommended changes to diagnosis of prostate cancer. For the past five years, doctors have been encouraged to abandon PSA (prostate specific antigen) screening for signs of prostate cancer in men ages 55 to 69.

This recommendation reflects discouragement with the standard PSA test because it returned a very large number of false positives. These false positives meant that tens of thousands of men were treated aggressively for a condition that was not life-threatening.

The new recommendation is that patients under 70 should be informed of the ambiguities involved in PSA screening, and be invited to weigh the pluses and minuses of knowing their PSA score.

After skin cancer, prostate cancer is the most common cancer affecting American men. This year, about 160,000 cases of prostate cancer will be diagnosed. It will cause the death of 26,730 men.

This is the dilemma physicians have had to deal with:

• The PSA test is not 100 percent reliable, yielding more false positives than true positives. It also yields many false negatives, missing the cancer altogether.
• False positives caused many thousands of men with high PSA scores to be subjected to treatment that proved unnecessary.
• These surgeries caused incontinence, bowel injury and impotence.
• Going back five years, the risk/benefit ratio was not considered strong enough to justify subjecting men to destructive biopsy, radiation and surgery.

The new recommendation of the U.S. Preventive Services Task is that the benefits of PSA testing outweigh the risks of inaction. But the recommendation is still ambiguous, leaving the decision to be tested for PSA up to "a man's values and preferences,"

Men who are very concerned about prostate cancer can elect to be screened. Men who are less concerned may elect to skip screening. Neither decision is right or wrong - but a great deal hangs in the balance.

The new recommendations are not final yet. Because of the controversies involved, they are open to public comment through May 8.