Balancing the Harms and Benefits of Early Detection of Prostate Cancer

BACKGROUND: The benefits of prostate cancer screening on an individual level remain unevaluated. METHODS: Between 1993 and 1999, a total of 43,987 men, aged 55-74 years, were included in the intervention arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC) section in the Netherlands, Sweden, and Finland. A total of 42,503 men, aged 55-74 years, were included in a clinical population in Northern Ireland. Serum prostate-specific antigen (PSA) <20.0 ng/mL was measured in all men at study entry. All men were followed for prostate cancer incidence and causes of death until December 31, 2006. RESULTS: The adjusted absolute difference in prostate cancer specific mortality between the intervention population and the clinical population increased with increasing PSA level at study entry, ie, 0.05 per 10,000 person-years for men who had a serum PSA level of 0.0-1.9 ng/mL and 8.8 per 10,000 person-years for men who had a serum PSA level of 10-19.9 ng/mL. To evaluate the risks of early detection, the number needed to investigate (NNI) and number needed to treat (NNT) to save 1 death from prostate cancer were calculated. Both NNI and NNT were higher for those who had lower PSA levels at study entry. The NNI was 24,642 men for patients who had a serum PSA level of 0.0-1.9 ng/mL and was 133 men for patients who had a serum PSA level of 10-19.9 ng/mL; the NNT was 724 men for patients who had a serum PSA level of 0.0-1.9 ng/mL and was 60 men for patients with a serum PSA level of 10-19.9 ng/mL. CONCLUSIONS: For men with a low serum PSA level, the benefits of aggressive investigation and treatment may be limited because they are associated with a large increase in cumulative incidence and potential overtreatment. Cancer 2010; 116: 4857-65. (C) 2010 American Cancer Society.