PTEN Loss Is Associated with Worse Outcome in HER2-Amplified Breast Cancer Patients but Is Not Associated with Trastuzumab Resistance.

ABSTRACT:

Purpose

To investigate the clinical relevance of PTEN in HER2-amplified and HER2-nonamplified disease.

Experimental design

We assessed PTEN status in two large adjuvant breast cancer trials (BCIRG-006 and BCIRG-005) using a PTEN immunohistochemical (IHC) assay that was previously validated in a panel of 33 breast cancer cell lines and prostate cancer tissues with known PTEN gene deletion.

Results

In the HER2-positive patient population, absence of tumor cell PTEN staining occurred at a rate of 5.4% and was independent of ER/PR status. In contrast, 15.9% of HER2-negative patients exhibited absence of PTEN staining with the highest frequency seen in triple-negative breast cancer (TNBC) subgroup versus ER/PR-positive patients (35.1% vs. 10.9%). Complete absence of PTEN s

SUBMITTER: Stern HM 

PROVIDER: S-EPMC4417419 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature