Prognostic and predictive signatures for treatment decisions.

Aim: We develop a subgroup selection procedure using both prognostic and predictive biomarkers to identify four patient subpopulations: low-and high-risk responders, and low-and high-risk nonresponders. Methods: We utilize three regression models to identify three sets of biomarkers: S, prognostic biomarkers; T, predictive biomarkers; and U, prognostic and predictive biomarkers. The prognostic signature C(S) combines with a predictive signature, either C(T) or C(U), to develop two procedures C(S, T) and C(S, U) for identification of four subgroups. Results: Simulation experiment showed that proposed models for identifying the biomarker sets S and U performed well, as did the procedure C(S, U) for subgroup identification. Conclusion: The proposed model provides more comprehensive characterization of patient subpopulations, and better accuracy in patient treatment assignment.