Identification of early breast cancer patient cohorts who may benefit from lapatinib therapy

Sodium-Dependent Glucose Transporter 1 (SGLT1) Stabled by HER2 Promotes Breast Cancer Cell Proliferation by Activation of the PI3K/Akt/mTOR Signaling Pathway in HER2+ Breast Cancer

Aerobic glycolysis is a hallmark of tumor cells. SGLT1 plays a vital role in glucose metabolism. However, whether SGLT1 could promote cell growth and proliferation in breast cancer remains unclear. Here, we investigated the expression of SGLT1 in breast cancer and examined its role in malignant behavior and prognosis. Further, we examined the SGLT1 expression in breast cancer tissues and its relationship with clinicopathologic characteristics. We clarified that SGLT1 was overexpressed in HER2+ breast cancer cell lines and was affected by HER2 status. We further found that SGLT1 affected breast cancer cell proliferation and patient survival by mediating cell survival pathway activation. SGLT1 was overexpressed in HER2+ breast cancers and associated with lymph node metastasis and HER2+ status. Inhibition of HER2 decreased SGLT1 expression, and the extracellular acidification rate was also reduced in the UACC812 and SKBR3 cell lines. These changes could be reversed by proteasome inhibitor treatment. Knockdown of SGLT1 blocked PI3K/Akt/mTOR signaling, thereby inhibiting cell proliferation. Further, we demonstrated that high SGLT1 was significantly correlated with shorter survival in all breast cancer patients and specifically in HER2+ breast cancer patients. Therefore, we conclude that SGLT1 is overexpressed in HER2+ breast cancer, thereby promoting cell proliferation and shortening survival by activating PI3K/Akt/mTOR signaling. This study submits that SGLT1 is promising not only as a novel biomarker of HER2+ breast cancer subtype but also as a potential drug target.

Emerging treatments for HER2-positive early-stage breast cancer: focus on neratinib

Over the last decades, a better understanding of breast cancer heterogeneity provided tools for a biologically based personalization of anticancer treatments. In particular, the overexpression of the human epidermal growth factor receptor 2 (HER2) by tumor cells provided a specific target in these HER2-positive tumors. The development of the monoclonal antibody trastuzumab, and its approval in 1998 for the treatment of patients with metastatic disease, radically changed the natural history of this aggressive subtype of breast cancer. These findings provided strong support for the continuous research in targeting the HER2 pathway and implementing the development of new anti-HER2 targeted agents. Besides trastuzumab, a series of other anti-HER2 agents have been developed and are currently being explored for the treatment of breast cancer patients, including those diagnosed with early-stage disease. Among these agents, neratinib, an oral tyrosine kinase inhibitor that irreversibly inhibits HER1, HER2, and HER4 at the intracellular level, has shown promising results, including when administered to patients previously exposed to trastuzumab-based treatment. This article aims to review the available data on the role of the HER2 pathway in breast cancer and on the different targeted agents that have been studied or are currently under development for the treatment of patients with early-stage HER2-positive disease with a particular focus on neratinib.

Clinical implications of tumor necrosis factor receptor 2 in breast cancer

Tumor necrosis factor receptor 2 (TNFR2) is a member of the tumor necrosis factor receptor family. Its high expression and oncogenic roles have been reported in several types of tumors in previous years. However, the clinical implication of TNFR2 in breast cancer (BC) tissue (i.e., not soluble TNFR2 in blood or genetic variation of TNFR2) has not been reported. In the present study, TNFR2 expression was detected in BC tissue using immunohistochemistry and, to the best of our knowledge, it was confirmed for the first time that TNFR2 was positively associated with increased tumor size, advanced clinical stage and higher pathological grade. Survival analysis revealed that TNFR2 was positively associated with shorter overall survival (OS) time and disease-free survival (DFS) time. In addition, univariate regression analysis demonstrated that TNFR2 expression (P=0.045), tumor size (P<0.0001), clinical stage (P<0.0001), pathological grade (P=0.002), estrogen and progesterone receptor and human epidermal growth factor receptor 2 (HER2) triple-status (P=0.001) all had a significant impact on the OS rate of patients with BC. TNFR2 expression (P=0.017), age (P=0.011), menopausal status (P<0.0001), tumor size (P=0.016), clinical stage (P=0.005), pathological grade (P=0.002) and estrogen/progesterone receptor and HER2 triple-status (P=0.008) were all shown to significantly impact the DFS rate of patients with BC. Multivariate regression analysis showed that only clinical stage (P=0.024), estrogen and progesterone receptor status and HER2 status (P=0.009) had a significant impact on the OS rate of patients with BC, while TNFR2 expression (P=0.043) and menopausal status (P=0.033) were shown to significantly impact the DFS rate of patients with BC. These data indicated that TNFR2 may perform important roles in the progression and prognosis of BC. This enriches previous understanding about TNFR2 in BC.

Adjuvant trastuzumab: a 10-year overview of its benefit

INTRODUCTION

Anti-HER2 targeted therapy is one of the key advances in the treatment of breast cancer that have occurred in the last 20 years. In the adjuvant setting, the use of trastuzumab has led to prolonged and sustained survival benefit with very little toxicity as also confirmed by the 10-year follow-up results from the pivotal trials. Despite the survival improvement, several key issues are not entirely resolved in this field. These issues have led to multiple research efforts in de-escalating or escalating the standard treatment with chemotherapy and 1 year of adjuvant trastuzumab. Areas covered: In this paper, we present an in depth overview on the state of the art on these key issues of refining decision-making in adjuvant anti-HER2 therapy. Expert commentary: Despite many important research efforts in the field, chemotherapy plus trastuzumab for a total duration of 1 year remains the standard of care. However, recent data showed that besides standard anthracycline- and taxane-based cytotoxic therapy, alternative chemotherapy regimens can now be proposed to patients with small tumors without nodal involvement and to women at high-risk of developing cardiotoxicity. Of note, besides HER2 itself, biomarkers predicting patients who may truly benefit from anti-HER2 agents are still lacking.