Department of Mathematics, Technische Universitaet Muenchen, Unit M4, Boltzmannstr 3, 85748 Garching b. Munich, Germany.
Department of Urology, University of Texas Health Science Center at San Antonio (UTHSCSA), 7703 Floyd Curl Dr., San Antonio, TX, USA 78229, USA; Department of Epidemiology/Biostatistics, University of Texas Health Science Center at San Antonio (UTHSCSA), 7703 Floyd Curl Dr., San Antonio, TX, USA 78229, USA.
Online risk prediction tools for common cancers are now easily accessible and widely used by patients and doctors for informed decision-making concerning screening and diagnosis. A practical problem is as cancer research moves forward and new biomarkers and risk factors are discovered, there is a need to update the risk algorithms to include them. Typically, the new markers and risk factors cannot be retrospectively measured on the same study participants used to develop the original prediction tool, necessitating the merging of a separate study of different participants, which may be much smaller in sample size and of a different design. Validation of the updated tool on a third independent data set is warranted before the updated tool can go online. This article reports on the application of Bayes rule for updating risk prediction tools to include a set of biomarkers measured in an external study to the original study used to develop the risk prediction tool. The procedure is illustrated in the context of updating the online Prostate Cancer Prevention Trial Risk Calculator to incorporate the new markers %freePSA and [-2]proPSA measured on an external case-control study performed in Texas, U.S.. Recent state-of-the art methods in validation of risk prediction tools and evaluation of the improvement of updated to original tools are implemented using an external validation set provided by the U.S. Early Detection Research Network.
Written by:
Ankerst DP, Koniarski T, Liang Y, Leach RJ, Feng Z, Sanda MG, Partin AW, Chan DW, Kagan J, Sokoll L, Wei JT, Thompson IM. Are you the author?
Reference: Biom J. 2011 Nov 17. Epub ahead of print.
doi: 10.1002/bimj.201100062
PubMed Abstract
PMID: 22095849
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