We sequenced cfDNA of a hormone receptor-positive, HER2-negative metastatic breast cancer (MBC) cohort with a high coverage to examine the prevalence and relevance of any detected variant. cfDNA of 44 MBC patients was isolated, followed by library construction using a customized targeted DNA panel with integrated unique molecular indices analyzing AKT1, AR, BRCA1, BRCA2, EGFR, ERCC4, ERBB2, ERBB3, ESR1, FGFR1, KRAS, MUC16, PIK3CA, PIK3R1, PTEN, PTGFR, and TGFB1.
One patient achieved a complete response (CR; endometrial carcinoma exhibiting both PIK3CA and PTEN mutations and complete PTEN loss) and two had a partial response (PR; both metastatic breast cancer).
Association of phosphatase and tensin homolog low and phosphatidylinositol 3-kinase catalytic subunit alpha gene mutations on outcome in human epidermal growth factor receptor 2-positive metastatic breast cancer patients treated with first-line lapatinib plus paclitaxel or paclitaxel alone.
HER3 and PTEN expressions may be predictive markers, and PTEN expression may be a predictive and prognostic biomarker for trastuzumab treatment in HER2-positive MBCs.
This article will characterize the biochemical and biological properties of a mutant PTEN protein found in a commonly used metastatic breast cancer cell line.
New tyrosine kinase inhibitors, monoclonal antibodies, PTEN (phosphatase and tensin homolog) pathway regulators, HER2 antibody-drug conjugates, and inhibitors of heat shock protein-90 are being evaluated to determine whether they may have a role to play in treating trastuzumab-resistant metastatic breast cancer.