TBCRC 002: a phase II, randomized, open-label trial of preoperative letrozole with or without bevacizumab in postmenopausal women with newly diagnosed stage 2/3 hormone receptor-positive and HER2-negative breast cancer.

Background: In preclinical studies, the expression of vascular endothelial growth factor (VEGF) in hormone receptor-positive breast cancer is associated with estrogen-independent tumor growth and resistance to endocrine therapies. This study investigated whether the addition of bevacizumab, a monoclonal antibody against VEGF, to letrozole enhanced the antitumor activity of the letrozole in the preoperative setting.

Methods: Postmenopausal women with newly diagnosed stage 2 or 3 estrogen and/or progesterone receptor-positive, HER2-negative breast cancer were randomly assigned (2:1) between letrozole 2.

Trastuzumab-Resistant HER2 Breast Cancer Cells Retain Sensitivity to Poly (ADP-Ribose) Polymerase (PARP) Inhibition.

HER2-targeted therapies, such as trastuzumab, have increased the survival rates of HER2 breast cancer patients. However, despite these therapies, many tumors eventually develop resistance to these therapies. Our lab previously reported an unexpected sensitivity of HER2 breast cancer cells to poly (ADP-ribose) polymerase inhibitors (PARPi), agents that target homologous recombination (HR)-deficient tumors, independent of a DNA repair deficiency.

Expression of the MHC Class II Pathway in Triple-Negative Breast Cancer Tumor Cells Is Associated with a Good Prognosis and Infiltrating Lymphocytes.

Triple-negative breast cancer (TNBC) is a subtype with heterogeneous patient outcomes. Approximately 40% of patients experience rapid relapse, while the remaining patients have long-term disease-free survival. To determine if there are molecular differences between primary tumors that predict prognosis, we performed RNA-seq on 47 macrodissected tumors from newly diagnosed patients with TNBC (n = 47; 22 relapse, 25 no relapse; follow-up median, 8 years; range, 2-11 years).

PARP1 and phospho-p65 protein expression is increased in human HER2-positive breast cancers.

Previous studies have shown that basal breast cancers, which may have an inherent "BRCAness" phenotype and sensitivity to inhibitors of poly (ADP-Ribose) polymerase (PARP), express elevated levels of PARP1. Our lab recently reported that HER2+ breast cancers also exhibit sensitivity to PARP inhibitors (PARPi) by attenuating the NF-κB pathway. In this study, we assessed PARP1 and phospho-p65, a marker of activated NF-κB levels in human breast cancer tissues.