Monday, June 12, 2017
US Task Force Changes Guidelines for Prostate Cancer Screening
The USPSTF had recommended in 2012 against such screening, saying the benefits of testing did not outweigh the risks. Since then, however, additional findings from two large clinical trials suggest that PSA-based screening may prevent up to between 1 and 2 prostate cancer-related deaths over approximately 13 years per 1,000 men screened. Testing may also prevent up to 3 cases of metastatic prostate cancer per 1,000 men screened over 13 years, the task force said.
While the change is subtle, resulting in a new C recommendation from a prior D recommendation, the draft guideline seeks to address confusion among many men about whether they should get screened for prostate cancer, a slow-growing disease that typically takes years before it becomes life-threatening. In its 2012 recommendation, the USPSTF noted that while screening could save the life of 1 man in every 1,000 tested, after a median follow-up of 11 years, widespread screening could also result in overdiagnosis. In addition to the potential for a false-positive result, and harm from a prostate biopsy — including pain, hematospermia, and infection — testing could lead to unnecessary treatment for a disease that would be relatively benign for many patients.
However, high-profile cases such as Ben Stiller’s had cast a shadow over the USPSTF’s 2012 recommendation. The actor revealed last fall that he had been diagnosed with prostate cancer in 2014 and said that the PSA test had saved his life. He further suggested that all men over the age of 40 get tested. The new draft guidelines fall short of that recommendation, but “[t]he USPSTF concludes with moderate certainty that, overall, the potential benefits and harms of PSA-based screening for prostate cancer in men ages 55 to 69 years are closely balanced,” it said in its draft guidance. “Each man’s individual values and preferences will determine whether he feels that the overall balance of potential benefits and harms is positive or negative. Zero, The End of Prostate Cancer, a nonprofit whose mission is to end prostate cancer, called the proposed change “a big step forward” but added in a statement that the “C rating is still insufficient and dangerous for high-risk men or men who — without testing — will develop aggressive or advanced disease.”
The USPSTF’s recommendations for men ages 70 and over were unchanged: They should not get PSA-based screening, as clinical evidence suggests no benefit from testing.
In a statement, the American Urological Association said that despite limited evidence that men in this age group may benefit from PSA-based screening, “we believe that selected older healthier men may garner a benefit from prostate cancer screening and should therefore talk to their doctors about the benefits and risks of prostate cancer testing.”
The draft guideline noted that two groups of men, African-Americans and those with a family history of prostate cancer, have a greater risk to develop the disease. There is not enough clinical data currently, however, to make separate specific recommendations on PSA-based tests for either group.
While African-American men have higher incidences of prostate cancer, compared to white men (203.5 versus. 121.9 cases per 100,000 men), and are more likely to die of prostate cancer (44.1 versus 19.1 deaths per 100,000 men) only 4 percent of the participants in the largest US-based clinical trial of screening were African-Americans “which is not enough to determine whether the overall trial results differed from African-American men,” the USPSTF said.
Similarly, it is generally accepted that men from families with a history of prostate cancer are more likely to develop the disease, but statistical evidence is insufficient to support different screening guidelines for this group, the task force said.
More than 25,000 men in the US died from prostate cancer in 2016, the USPSTF said, citing statistics from the National Cancer Institute.