A large retrospective study in California found that annual PSA screening is highly effective in reducing prostate cancer deaths. The report comes in the midst of national discussions over the use of PSA testing for the early detection of prostate cancer.
The study looked at retrospective data from more than 400,000 men. The research team found that annual screening reduced prostate cancer deaths by 64% for men 55 to 75 years old. Men in this group also had a 24%lower risk of dying from other causes.
After evaluating the data, the authors wrote that the efficacy of screening “drops off rapidly for intervals greater than 12-18 months.” For comparison, for men between 55-74 years, the reduction in prostate cancer death fell to 54% with 18-24 months between screenings, and to 46% with a 2-3 year screening period. (The authors noted that this last figure was not statistically significant upon analysis.)
For older men, annual screening was also beneficial. Men ages 70-74 years who were screened every 12-18 months had a 67% lower risk of prostate cancer death. Men ages 75-79 years with the same screening intervals had a 52% lower risk of dying from the disease.
The study did not find a benefit for any screening interval for men younger than 55 years.
The men in the study all underwent PSA testing at the Kaiser Permanente North California clinic, which is part of the University of California Medical Center. The researchers divided men into groups according to PSA testing intervals, then compared death rates after follow-up of 12 to 16 years.
The authors concluded, “When combined with active surveillance to prevent overtreatment, these data lend support for yearly population-based PSA screening for prostate cancer for men aged 55-74 who are in good health.”
Comparison to other PSA screening studies
A number of earlier high-quality randomized trials have similarly found a benefit of PSA screening. The European Randomized Study of Screening for Prostate Cancer (ERSPC) found that screening every 4 years resulted in a 21%lower risk of men developing prostate cancer. A sub-analysis of data from this trial looked at men with a 2-year screening interval, which showed a 44%reduction in prostate cancer deaths. “This suggests that the choice of a shorter screening interval may have led to more powerful results,” the authors wrote.
Published results from the Prostate, Lung, Colorectal, and Ovarion (PLCO) Cancer Screening Trial did not show a significant benefit from PSA screening. However, later critical analysis of the data from PLCO showed that the study was highly contaminated, with nearly 90% in the control group undergoing PSA screening. This skewed the results of PLCO. The most recent independent re-analysis of the PLCO trial reported a 27% to 32% lower mortality rate in the screening arm, similar to the ERSPC trial.
Urology. 2018 Aug;118:119-126. doi: 10.1016/j.urology.2018.02.049.