This case-sensitive code system http://hl7.org/fhir/us/breastcancer/CodeSystem/oncology-StageTimingPrefixCS defines the following codes:

Code	Display	Definition
cli	Clinical stage: Staging performed prior to surgery, based on evidence such as physical examination, imaging, and/or biopsy.	Clinical stage: Staging performed prior to surgery, based on evidence such as physical examination, imaging, and/or biopsy.
path	Pathologic stage: Staging performed based on examination of tissue samples removed during surgery, in addition to physical examination and imaging.	Pathologic stage: Staging performed based on examination of tissue samples removed during surgery, in addition to physical examination and imaging.
postther_cli	Post-therapeutic (post-neoadjuvant) clinical staging based on clinical examination after the first treatment with systemic drugs or radiation, when no surgery has been performed.	Post-therapeutic (post-neoadjuvant) clinical staging based on clinical examination after the first treatment with systemic drugs or radiation, when no surgery has been performed.
postther_path	Post-therapeutic (post-neoadjuvant) pathologic staging, based on tissue samples removed during surgery after the first treatment with systemic drugs or radiation.	Post-therapeutic (post-neoadjuvant) pathologic staging, based on tissue samples removed during surgery after the first treatment with systemic drugs or radiation.