PSA repeat screening strategy should be tailored to baseline PSA
medwireNews: Baseline prostate-specific antigen (PSA) levels in men screened between the ages of 55 and 60 years are significantly associated with long-term risk for clinically significant prostate cancer, shows an analysis of data from the PLCO Cancer Screening Trial.
Therefore, “[f]uture prostate cancer screening among middle-aged men (ie, aged 55–60 years) should be individually tailored based on baseline PSA levels to reduce the risk of overdiagnosis and overtreatment of indolent cancers,” say Evan Kovac (Montefiore Medical Center, New York, USA) and co-investigators.
The secondary analysis of PLCO Cancer Screening Trial data included 10,968 men who were aged 55 to 60 years (median age 57 years) when they enrolled between 1993 and 2001.
The researchers found that the 13-year actuarial incidence of any prostate cancer and of clinically significant prostate cancer in these men increased significantly with increasing baseline PSA.
For clinically significant prostate cancer the incidence was:
- 0.4% for men with a baseline PSA level of 0.49 ng/mL or lower,
- 1.5% in those with a level of 0.50–0.99 ng/mL,
- 5.4% with a level of 1.00–1.99 ng/mL,
- 10.6% with a level of 2.00–2.99 ng/mL,
- 15.3% with a level of 3.00–3.99 ng/mL,
- 29.5% with a level of 4.00 ng/mL or higher.
In addition, there were 15 prostate cancer-specific deaths during the 13 years of follow-up, 60.0% of which occurred among men with a baseline PSA level of 2.00 ng/mL or higher.
Writing in JAMA Network Open, Kovac and co-authors say that although there appears to be “no absolute baseline PSA cutoff level under which the 13-year risk of […] clinically significant [prostate cancer] is 0, this risk was higher among men with a baseline PSA level of 2.00 ng/mL or greater.”
This suggests that “repeated screening can be less frequent among men aged 55 to 60 years with a low baseline PSA level (ie, <2.00 ng/mL) and possibly discontinued among those with baseline PSA levels of less than 1.00 ng/mL,” they add.
The team points out that the majority of men would be affected by such changes in the frequency of repeat screening strategy because in the current study 83% had baseline PSA levels below 2.00 ng/mL.
Kovac et al conclude: “Our results support the modification of future screening practices based on baseline PSA level and could help to reduce the need for prostate biopsy and overdetection of clinically indolent [prostate cancer] without significantly compromising oncologic outcomes.”
They add: “Longer follow-up of the PLCO Cancer Screening Trial to 20 years, expected in 2022, will hopefully provide much-anticipated [prostate cancer]-specific mortality data associated with baseline PSA testing.”
By Laura Cowen
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