http://www.ohdsi.org/web/wiki/lib/exe/fetch.php?media=documentation:oncology:cancer_diagnostic_features_2017-12-12.pptx
https://docs.google.com/document/d/12PWrP9MNgTq3J-ApGZGLhgAvgefK3sEeW2uUOOTr_Vg/edit#