SNOMED CT	Breast Cancer Staging - 8th Edition	Source
http://idea.rpi.edu/ontologies/cancer_staging_terms.owl#Grade2	http://purl.bioontology.org/ontology/SNOMEDCT/258352004	LOOM
http://idea.rpi.edu/ontologies/cancer_staging_terms.owl#Grade3	http://purl.bioontology.org/ontology/SNOMEDCT/258353009	LOOM
http://idea.rpi.edu/ontologies/cancer_staging_terms.owl#Grade1	http://purl.bioontology.org/ontology/SNOMEDCT/258351006	LOOM