Professor Schroeder did, however, review the Rotterdam data to some extent as well as the Swedish data. In their 11-year data, 34,833 men were screened and 2,028 CaP cases were diagnosed in the screening arm, which translates to a 29% relative risk reduction. The NNI and NNM are 616 and 39.9 to save one life. The Göteborg trial began in 1994 and joined the ERSPC in 1996. They randomized 20,000 men and Dr. Jonas Hugosson reported that the CaP mortality absolute risk reduction was 0.40%. The rate ratio of CaP death was 0.56, meaning that the risk reduction of CaP death is 44%. The NNS is 293, and the NNT is 12. This data may predict the longer-term outcome of ERSPC, he said. Sweden has the highest incidence and CaP mortality rates in Europe.
They also evaluated metastatic disease and the effect that screening has on it. A metastatic lesion needed to be radiographically documented or was assumed with a PSA >100ng/ml. In the screened arm there are 256 M+ patients, compared with 416 in the control arm, roughly a 30% difference. There is a 52% relative risk reduction for having CaP metastasis at the time of diagnosis. This decreases and reverses so that the screened patients actually have a higher likelihood of metastasis over the follow-up period. Most of the metastatic cases are detected in the first screening round, but this needs further evaluation regarding the implications.
With respect to overdiagnosis and overtreatment, overdiagnosis in inherent in screening, but it is high at 54% in the ERSPC. The ERSPC 8-year detection rate was 8.3%, compared to an incidental rate of 20% and 21.9% in the PCPT control arm. To minimize overdiagnosis and over treatment he advised to use risk modifiers as decision tools and develop multiplex tools to assess patients and their cancers.
Presented by Fritz H. Schroeder, MD at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.