On April 11, the U.S. Preventive Services Task Force (USPSTF) posted its new draft recommendation statement(www.uspreventiveservicestaskforce.org) and three draft evidence reviews on screening for prostate cancer. In addition to a traditional systematic evidence review,(www.uspreventiveservicestaskforce.org) the task force also issued a contextual review on overdiagnosis in prostate cancer screening decision models(www.uspreventiveservicestaskforce.org) and a contextual overview of prostate cancer screening decision models.(www.uspreventiveservicestaskforce.org)
Based on its systematic review of the evidence, the USPSTF determined that the potential benefits and harms of prostate-specific antigen (PSA)-based screening are closely balanced in men ages 55-69 and said that decisions regarding screening in this group should be individualized -- a "C" recommendation.(www.uspreventiveservicestaskforce.org)
The task force specifically recommends that clinicians inform men ages 55-69 about the potential benefits and harms of PSA-based screening as part of the decision-making process so each man has an opportunity to understand those potential benefits and harms and incorporate his values and preferences into the decision.
For men 70 and older, the potential benefits of PSA-based screening don't outweigh the harms, so this group should not be screened for prostate cancer -- a "D" recommendation.
- On April 11, the U.S. Preventive Services Task Force (USPSTF) posted its draft recommendation statement and three draft evidence reviews on screening for prostate cancer.
- The USPSTF determined that the potential benefits and harms of prostate-specific antigen (PSA)-based screening are closely balanced in men ages 55-69 and said that decisions on screening men in this group should be individualized -- a "C" recommendation.
- For men ages 70 years and older, the potential benefits of PSA-based screening don't outweigh the harms, so this group should not be screened for prostate cancer.
This draft recommendation applies to adult men who haven't previously been diagnosed with prostate cancer and who have no symptoms of the disease. Importantly, the guidance applies to both men at average risk and those at increased risk for prostate cancer, such as African-American men and men with a family history of prostate cancer.
"Prostate cancer is one of the most common cancers to affect men, and the decision about whether to begin screening using PSA-based testing is complex," said task force member Alex Krist, M.D., M.P.H., in a news bulletin.(www.uspreventiveservicestaskforce.org) "For men who are more willing to accept the potential harms, screening may be the right choice for them. Men who are more interested in avoiding the potential harms may choose not to be screened.
"In the end, men who are considering screening deserve to be aware of what the science says, so they can make the best choice for themselves, together with their doctor."
Draft Recommendation Details
The USPSTF found that adequate evidence from randomized clinical trials showed that PSA-based screening programs in men ages 55-69 may prevent as many as one to two deaths from prostate cancer per 1,000 men screened over a 13-year period. Screening programs may also prevent as many as three cases of metastatic prostate cancer per 1,000 men screened for 13 years.
Adequate evidence from randomized clinical trials also showed no mortality benefit of PSA-based screening for men 70 and older.
Potential harms from screening and treatment can occur immediately. Harms from PSA-based screening include frequent false-positive results. One major trial involving men screened every two to four years concluded that during a 10-year period, more than 15 percent of men experienced at least one false-positive test result.
Harms of related diagnostic procedures include complications of prostate biopsy, such as pain, hematospermia and infection. About 1 percent of prostate biopsies result in complications requiring hospitalization.
PSA-based screening for prostate cancer leads to diagnosis of prostate cancer in some men whose cancer would never have become symptomatic during their lifetime; thus, treatment provides them no benefit. Follow-up to previous large, randomized trials has suggested that 20 percent to 50 percent of men diagnosed with prostate cancer through screening may be overdiagnosed, with the highest rates in men 70 and older.
As for potential harms of prostate cancer treatment, they include sexual impotence, urinary incontinence and bothersome bowel symptoms. About one in five men who have a radical prostatectomy develop long-term urinary incontinence requiring diaper use, and more than two in three men experience long-term sexual impotence.
Similarly, more than half of men who have radiation therapy experience long-term sexual impotence, and as many as one in six men experience long-term problematic bowel symptoms, including urgency and incontinence.
The draft recommendation is also based in part on new evidence on the use of active surveillance, which includes regular, repeated PSA testing and often repeated digital rectal examination and prostate biopsy. Active surveillance has become a more common treatment choice for men with lower-risk prostate cancer and may reduce the chance of overtreatment. It may also offer men the opportunity to delay -- or even completely avoid -- active treatment and its potential complications.
In a study that assessed community-based urology practice in the United States between 2010 and 2013, about half of men with low-risk prostate cancer were treated with radical prostatectomy. In comparison, the rate of active surveillance use in this population increased from 14.3 percent in 2009 to 40.4 percent in 2013.
Focus on High-risk Populations
In developing the draft recommendation, task force members specifically reviewed evidence on the benefits and harms of screening in men at higher risk for prostate cancer, such as African-American men and those with a family history of the disease.
"Clinicians should speak with their African-American patients about their increased risk of developing and dying from prostate cancer, as well as the potential benefits and harms of screening," said USPSTF Chair Kirsten Bibbins-Domingo, Ph.D., M.D., M.A.S., in the bulletin. "This recommendation applies to African-American men, but we remain particularly concerned about the striking absence of evidence to guide these high-risk men specifically as they make decisions about screening. Additional research on prostate cancer in African-American men should be a national priority."
The task force also recommended that clinicians talk with patients who have a family history of prostate cancer, particularly in a father or brother, about their increased risk of developing the disease. The group called for targeted research on the potential benefits and harms of screening in these men.
Family Physician's Perspective
Jennifer Frost, M.D., medical director for the AAFP Health of the Public and Science Division, stressed that the recommendations for each age group are based on the balance of benefits and harms of screening.
"The benefits of prostate cancer screening are small, with only one per 1,000 men offered screening possibly avoiding death from prostate cancer," she told AAFP News. "There are also significant harms associated with screening, including false-positives, treatment of disease that would not otherwise impact a man's life, and complications from treatment such as incontinence and impotence.
"When the benefits are small, it's harder to justify the potential harms."
Frost pointed out that in 2012, the USPSTF and the AAFP recommended against PSA-based screening for prostate cancer for all men, a recommendation that was added to the Choosing Wisely list of tests and procedures that may be overused.
The revised guidance in the current draft recommendation is based largely on the same studies that informed the 2012 recommendation, Frost said, but there has been longer-term follow-up to the research and a shift in treatment strategies.
"The follow-up data indicate a similar impact on mortality as the earlier data, but also show a potential reduction in metastatic disease," she explained. "And since the earlier recommendation, treatment has become less aggressive, with a significant portion of men undergoing active surveillance rather than immediate surgery or radiation."
As for using the PSA test to detect prostate cancer, Frost acknowledged that it's not a great test but said it's the best option available.
"It has a very high false-positive rate, with more than 15 percent of men experiencing a false-positive," she said. "These men then undergo further testing -- with the associated risks. Of those who have a 'true positive,' up to 50 percent may be overdiagnosed, which means their prostate cancer would not have become clinically significant in their lifetime."
Frost said when family physicians discuss the risks and benefits of prostate cancer screening with men ages 55-69, multiple factors should be considered, including anything that would increase or decrease a man's risk of developing prostate cancer.
"If a man's father developed prostate cancer at age 80, but then died six years later of a different cause, his risk is not significantly increased," she said. "If, however, a man's father and uncle both developed cancer while in their early 60s, which rapidly progressed, resulting in their early death, then he is at much higher risk and may be more likely to risk the potential harms associated with screening."
The USPSTF is inviting comments on its draft recommendation statement,(www.uspreventiveservicestaskforce.org) as well as on the draft systematic evidence review,(www.uspreventiveservicestaskforce.org) the contextual review on overdiagnosis in screening decision models(www.uspreventiveservicestaskforce.org) and the overview of screening decision models.(www.uspreventiveservicestaskforce.org)
The public comment window is open until 8 p.m. EDT on May 8. All comments received will be considered as the task force prepares its final recommendation.
The AAFP will review the USPSTF's draft recommendation statement and supporting evidence and provide comments to the task force. The Academy will release its own recommendation on the topic after the task force finalizes its guidance.
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