Automated mRNA-Based Detection of ER, PR, HER2, and Ki-67 in Breast Cancer Tissue and Cytology Samples in Resource-Limited Settings

Background

Accurate detection of estrogen and progesterone receptors (ER/PR), HER2, and Ki-67 is essential for molecular classification of breast cancer and in deciding upon tailored treatment. In many low- and middle-income countries (LMICs), access to histopathology and immunohistochemistry (IHC) is limited. STRAT4, an automated RT-qPCR assay performed on the widely available GeneXpert platform, offers a potential alternative. We evaluated the performance of STRAT4 on core biopsy, unstained smear of fine-needle aspiration biopsy (FNAB-US), and cellblock samples compared with conventional IHC in 178 histopathology-confirmed breast cancer patients.