Prognostic significance of progesterone receptor-positive tumor cells within immunohistochemically defined luminal A breast cancer.

ABSTRACT:

Purpose

Current immunohistochemical (IHC)-based definitions of luminal A and B breast cancers are imperfect when compared with multigene expression-based assays. In this study, we sought to improve the IHC subtyping by examining the pathologic and gene expression characteristics of genomically defined luminal A and B subtypes.

Patients and methods

Gene expression and pathologic features were collected from primary tumors across five independent cohorts: British Columbia Cancer Agency (BCCA) tamoxifen-treated only, Grupo Español de Investigación en Cáncer de Mama 9906 trial, BCCA no systemic treatment cohort, PAM50 microarray training data set, and a combined publicly available microarray data set. Optimal cutoffs of percentage of progesterone receptor (PR) -positive tumor ce

SUBMITTER: Prat A 

PROVIDER: S-EPMC3532392 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature