Optimize querying in DiscreteCNACache
Optimize querying in DiscreteCNACache

Signed-off-by: Abeshouse, Adam A./Sloan Kettering Institute <abeshoua@mskcc.org>

Former-commit-id: bc8d33ee4296a8e87a65173e47da43723c52c41b
alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend