TABLE 2.
Summary of Characteristics of the Recursive Partitioning Analysis (RPA) Groupings After Condensing Into the Fewest Groups Possible
| When the Number of Metastatic Sites is... | And Biomarker Status is... | And the Grade and cT Stage is... | Then the Prognostic Stage Group is... |
|---|---|---|---|
| 1 | Any ER, any PR, HER2+ | Any grade, any cT stage | IVA |
| ER+,PR−, HER2− | Any grade, any cT stage | IVB | |
| ER+,PR+, HER2− | Grade 1–2, any cT stage | IVA | |
| Grade 3, cT0–3 | IVA | ||
| Grade 3, cT4 | IVB | ||
| ER−, any PR, HER2− | Any grade, any cT stage | IVC | |
| 2 | ER+, PR+, HER2+ | Any grade, any cT stage | IVA |
| ER−, any PR, HER2+ | Any grade, any cT stage | IVB | |
| ER+,PR−, HER2+ | Any grade, any cT stage | IVB | |
| ER+,PR+, HER2− | Any grade, any cT stage | IVB | |
| ER+/PR−/HER2− | Any grade, any cT stage | IVC | |
| ER−, any PR, HER2− | Any grade, any cT stage | IVC | |
| ≥3 | Any ER, any PR, any HER2 | Any grade, any cT stage | IVC |
Analysis based on adults with de novo metastatic breast cancer from the national cancer data base (2010–2013).
ER indicates estrogen receptor; HER2, human epidermal growth factor receptor 2; PR, progesterone receptor.