Relevance of progesterone receptor immunohistochemical staining to Oncotype DX recurrence score

Objective/BackgroundProgesterone-receptor negativity (PR−) is predictive of adverse outcomes in estrogen receptor-positive (ER+) breast cancer. The Oncotype DX assay provides risk stratification for hormone receptor-positive (HR+) invasive breast cancer; however, the association of PR status and Oncotype DX recurrence scores (RSs) is less clear.MethodsWe designed an analysis to determine whether a significant difference exists in the RS for ER+/PR− tumors when compared with ER+/PR+ breast cancer. Three hundred and fifty patients with HR+ invasive breast cancer who underwent Oncotype DX testing at our institution from December 2006 to October 2013 were i