Favorable biology (ER+/HER2- and Low Grade) can downstage an anatomically large tumor. Conversely, unfavorable biology (Triple Negative or HER2+) can upstage a small tumor in the prognostic framework.

Always report the Prognostic Stage to the patient, as it more accurately reflects their 5-year survival probability. For example, a T2N0 Grade 1 ER+ tumor is Anatomically Stage IIA but Prognostically Stage IA.

In the 8th Edition, if a patient has a T1-T2 N0 ER+/HER2- tumor with an Oncotype DX Recurrence Score < 11, they are automatically assigned to Prognostic Stage IA regardless of grade.