Abstract: The present disclosure generally relates to methods and compositions for identifying and/or treating cancer patients harboring one or more molecular alterations in clinically important biomarkers, preferably in multiplexed assays, such that multiple biomarkers can be assayed simultaneously. In one embodiment, the disclosure relates to methods for rapid screening large populations of biological samples by using a high-throughput multiplexed assay to assess relative prevalence of multiple indications, optionally followed by a second analytical assay with higher sensitivity and specificity.