Update From the Medical Journals: May 2012
January 1, 2012
By Mary Pickett, M.D.
What's the latest news in the medical journals this month? Find out what your doctor is reading.
Almost two-thirds of men who are older than 50 have had at least one screening PSA (prostate specific antigen) test. This blood test checks for prostate cancer. But the PSA test has been controversial.
In 2010, the American Cancer Society (ACS) said doctors should not automatically offer the test. Instead, according to the ACS, they should talk with patients about how uncertain we are about the benefits of the test.
Now, the U.S. Preventive Services Task Force (USPSTF) says men at low risk for prostate cancer should not be screened at all. The test does more harm than good, according to the USPFTF. The journal Annals of Internal Medicine published this group's recommendations online May 21. The USPSTF had released a draft of this same recommendation in October. It invited comments from the public and from physicians. More than 3,000 were sent before the comment period ended.
The PSA test mostly finds early-stage prostate cancer. The task force made its recommendation after reviewing about 9,000 studies. In studies, two out of five cancers found by a PSA test were too slow growing to ever cause harm. About 90% of men diagnosed with prostate cancer are treated. And the number of lives saved is very small. In fact, researchers have not shown a difference in "all-cause" mortality (death from all causes considered together) from prostate cancer screening tests.
The treatment for prostate cancer often leaves men with long-term, undesirable side effects. These include loss of sexual function, incontinence (leaking urine), rectal spasms or urgency to have a bowel movement. The most common treatment for prostate cancer is surgery to remove the prostate (prostatectomy). The chance of dying during this operation is about 1 in 200. The USPSTF points out that for prostate cancers found by screening, treatment doesn't prevent deaths or extend lives for most men. But men who are treated "are subjected to significant harms."
African-American men and men with a family history of prostate cancer (relatives who were younger than 65 when their cancers were found) are more likely to have aggressive cancers. Despite the extra risk, the USPSTF is not recommending screening for these men. The new recommendation does not apply to men who have symptoms such as difficulty urinating or blood in the urine. The PSA test might still be useful to check for cancer in men with symptoms.
A stress fracture (also called "fatigue fracture") occurs when a bone becomes less flexible and less able to bend. It absorbs stress along a line of tension and eventually breaks in a fine straight line. It is possible for stress fractures to occur in the femur (the thigh bone). When this occurs, they are called atypical fractures of the femur.
Two years ago, the U.S. Food and Drug Administration (FDA) first notified doctors of a concern that osteoporosis drugs might be linked to these atypical fractures. The drugs are called "bisphosphonates." They include alendronate (Fosamax), risedronate (Actonel) and etedronate (Didronel). These medicines encourage bones to add mineral, which makes them more dense. They lower the risk for hip fracture. But the FDA said they might increase the risk for atypical fractures of the femur.
Last year, a study proved this to be true. This month another study confirmed the connection. On May 21, a study in the Archives of Internal Medicine reported on 477 patients who had femur fractures below the hip. Thirty-nine of them had atypical fractures. The others had a more classic fracture (a snapping or splintering of the bone, not a fine line) that we typically see with trauma. Eighty-two percent of the people who had atypical fractures were taking bisphosphonate drugs. Only 6% of people with typical fractures were taking bisphosphonates. The researchers divided patients into groups according to how long they had taken an osteoporosis drug. They analyzed the data and found that the odds of having an atypical fracture were much larger if a person had taken the drugs for at least five years.
Osteoporosis drugs strengthen bones, but the bones also become abnormally stiff. This study adds to evidence that bisphosphonate drug treatment has risks as well as benefits.
It seems likely that most of the benefit comes in the first several years of treatment. Most doctors limit the time of treatment with bisphosphonate drugs to five years or less. Most likely, this study will help that limit become a standard of practice. For people who have severe osteoporosis, several years of treatment with a bone-building medicine probably offers more benefit than risk.
Moyer, Virginia A, MD, MPH, on behalf of the U.S. Preventive Services. "Screening for Prostate Cancer: U.S. Preventive Services Task Force Recommendation Statement." Annals of Internal Medicine. Published online at www.annals.org May 22, 2012.
Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.