The U.S. Preventive Services Task Force determined that the potential benefits and harms of prostate-specific antigen (PSA)-based screening are closely balanced in some older men and that their decision about whether to be screened should be an individual one.
Clinicians should talk to men ages 55 to 69 about the potential benefits and harms of screening, according to the Task Force. This is a grade C recommendation, defined as offering a specific service depending on individual patient circumstances. For men ages 70 years and older, the potential benefits of PSA-based screening do not outweigh the harms, and these men should not be screened for prostate cancer. This is a grade D recommendation, indicating that the use of a particular service should be discouraged.
The draft recommendation, along with a draft evidence review, draft contextual review, and draft contextual review on overdiagnosis, were published April 11 on the Task Force's website. The drafts are open for public comment until May 8.
The draft recommendation applies to adult men who have not been previously diagnosed with prostate cancer and have no signs or symptoms of the disease, including men who are at increased risk for death from prostate cancer, such as African-American men and men with a family history of prostate cancer.
The draft recommendation stated that adequate evidence from randomized clinical trials shows that PSA-based screening programs in men ages 55 to 69 years may prevent up to one to two deaths from prostate cancer over approximately 13 years per 1,000 men screened. Screening programs may also prevent up to three cases of metastatic prostate cancer per 1,000 men screened over 13 years. Adequate evidence from randomized clinical trials is consistent with no mortality benefit of PSA-based screening for prostate cancer in men ages 70 years and older.
Potential harms of screening include frequent false-positive results, the draft recommendation continued. One major trial in men screened every two to four years concluded that, over 10 years, more than 15% of men experienced at least one false-positive test result. Harms of diagnostic procedures include complications of prostate biopsy, such as pain, hematospermia, and infection. Approximately 1% of prostate biopsies result in complications requiring hospitalization. The false-positive and complication rates from biopsy are higher in older men. Adequate evidence suggests that the harms of screening and diagnostic procedures are at least small.
The draft recommendation also noted that PSA-based screening for prostate cancer leads to the diagnosis of prostate cancer in some men whose cancer would never have become symptomatic during their lifetime (overdiagnosis). Follow-up of large randomized trials suggests that 20% to 50% of men diagnosed with prostate cancer through screening may be overdiagnosed. Due in part to reduced life expectancy and delays in treatment benefits, overdiagnosis rates increase with age and are highest in men ages 70 years and older.
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. More than half of men who have radiation therapy experience long-term sexual impotence and up to one in six men experience long-term bothersome bowel symptoms, including bowel urgency and fecal incontinence. Adequate evidence suggests that the harms of overdiagnosis and treatment are at least moderate, according to the draft recommendation.
“The decision about whether to be screened for prostate cancer requires that each man incorporate his own values and preferences with an understanding of the potential benefits and harms of screening,” stated the recommendation. “The potential harms of screening, diagnostic procedures, and treatment occur soon after screening takes place. While the potential benefits may occur any time after screening, they generally occur years after treatment, because progression from asymptomatic, screen-detected cancer to symptomatic, metastasized cancer or death (if it occurs at all) may take years or decades.”