Posted 10/18/11 on GoozNews
Last Friday at 3 p.m., the Agency for Healthcare Research and Quality held a telephone briefing to inform the press and public about the U.S. Preventive Services Task Force recommendation against routine screening of prostate specific antigen (PSA) levels in middle-aged men. The “D” recommendation, now open for public comment, said the harms from false positives and overtreatment of prostate cancer identified by elevated PSA levels outweighed any benefits that would be achieved by the early identification of the relatively small percentage of cases that would lead to metastatic disease and early death.
They posted no slides to go along with the three presentations made at the briefing. They didn’t spell out the names of the men who spoke (I scribbled down Moyer, Chou and LeFebre). And, when they concluded their presentations, they didn’t take questions.
Yet the data they presented was persuasive. Here are a few facts:
- Over a ten-year period, about 15 to 20 percent of men receiving routine PSA tests will be sent for biopsies because of elevated PSA values;
- Yet elevated PSA values are not specific to cancer; 80 percent of the men sent for biopsies will not have cancer;
- About one in 24 men sent for biopsies will wind up being hospitalized with complications from the procedure within a month;
- About 90 percent of all prostate tumors successfully identified by the biopsies will not be metastatic, but will be localized, which makes them prime candidates for “watchful waiting,” not aggressive treatment;
- Yet 75 percent of those identified with cancer will wind up receiving either radiation, or surgery, or both;
- Five out of every 1,000 men who have prostate cancer surgically removed will die within 30 days of complications of the operation;
- Ten to 70 of 1,000 men who receive surgery will have serious complications, including heart attacks and strokes;
- Anywhere from 200 to 300 of those 1,000 men who receive aggressive treatment for prostate cancer (radiation or surgery) will become either incontinent or impotent or both;
- In the European trial, which showed benefit from PSA testing while the U.S. trial did not, there needed to be 48 men screened every year for ten years to save one person from dying from prostate cancer.
To sum up, treat 1,000 men identified with prostate cancer and 200 to 300 will become impotent or incontinent; among those who get surgery, five will die from operation complications, and 10 to 70 will have heart attacks, strokes or other serious adverse events. That compares to about 20 lives not lost to prostate cancer, if I’m doing the math right.
Later this week, the USPSTF is expected to make a similar finding regarding screening women over 30 for the human papillomavirus to detect cervical cancer. They will continue backing the more traditional Pap test, which is given every three years to women between 20 and 65. The report, which appears in the current Annals of Internal Medicine, said the HPV test was more accurate than the Pap test in detecting pre-cancerous lesions, but generated more false positives.
For those of us who follow medicine closely, we understand science drives these studies, just as science drives the decision-making process at USPSTF. But its parent agency, AHRQ, does itself no favors when it explains these scientific decisions late on a Friday afternoon, a week after the announcement, and gives the press and public no chance to ask questions. Get out of your foxholes. Say it loud, and say it proud. Whom do you want the public to gets its medical information from — Michelle Bachmann?
Merrill Goozner is an independent health care journalist who maintains a blog at GoozNews.