To determine the Prostate Cancer Stage Group, two more categories are needed besides TNM - Gleason Grade Group and PSA categorical value (note- not the actual lab value).

So at least per AJCC definition, Gleason Grade Group is a non-anatomical category rather than a stage group (this already seems to be reflected in how the profile is modeled, not containing any reference Observations).

It would be suitable to create a StageCategory parent profile to capture the non-TNM categories of StageGroup - G, PSA for Prostate, ER, PR, HER2, G, OncotypeDx for Breast, HPV for Oropharynx, etc. StageCategory profile could reference lab/genomic profiles from which the raw data is coming from (they should exist as separate resources though, as onco-specific EMRs will have access to the stage categories but not necessarily the actual lab values).

Reference: https://www.facs.org/media/2zvlrdmi/ajcc_staging_rules_8th_ed.pdf