Robot-assisted laparoscopic removal of an extraperitoneal pelvic solitary fibrous tumor

•Pelvic SFTs are rare, typically benign soft tissue neoplasms that pose a diagnostic challenge for gynecologists.•Retroperitoneal pelvic SFTs can mimic gynecologic malignancies and should be considered in diagnosis of a solitary pelvic mass.•Pathologic diagnosis is typically confirmed by immunohistochemistry staining positively for CD34 and STAT6.•Complete surgical excision is recommended for these tumors and can be completed with a minimally invasive approach.•Close long-term follow-up is necessary due to possible recurrence or metastasis, especially for high-risk pathologic features.

Perspectives on Triple-Negative Breast Cancer: Current Treatment Strategies, Unmet Needs, and Potential Targets for Future Therapies

Triple-negative breast cancer (TNBC), characterized by the absence or low expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2), is the most aggressive subtype of breast cancer. TNBC accounts for about 15% of breast cancer cases in the U.S., and is known for high relapse rates and poor overall survival (OS). Chemo-resistant TNBC is a genetically diverse, highly heterogeneous, and rapidly evolving disease that challenges our ability to individualize treatment for incomplete responders and relapsed patients. Currently, the frontline standard chemotherapy, composed of anthracyclines, alkylating agents, and taxanes, is commonly used to treat high-risk and locally advanced TNBC. Several FDA-approved drugs that target programmed cell death protein-1 (Keytruda) and programmed death ligand-1 (Tecentriq), poly ADP-ribose polymerase (PARP), and/or antibody drug conjugates (Trodelvy) have shown promise in improving clinical outcomes for a subset of TNBC. These inhibitors that target key genetic mutations and specific molecular signaling pathways that drive malignant tumor growth have been used as single agents and/or in combination with standard chemotherapy regimens. Here, we review the current TNBC treatment options, unmet clinical needs, and actionable drug targets, including epidermal growth factor (EGFR), vascular endothelial growth factor (VEGF), androgen receptor (AR), estrogen receptor beta (ERβ), phosphoinositide-3 kinase (PI3K), mammalian target of rapamycin (mTOR), and protein kinase B (PKB or AKT) activation in TNBC. Supported by strong evidence in developmental, evolutionary, and cancer biology, we propose that the K-RAS/SIAH pathway activation is a major tumor driver, and SIAH is a new drug target, a therapy-responsive prognostic biomarker, and a major tumor vulnerability in TNBC. Since persistent K-RAS/SIAH/EGFR pathway activation endows TNBC tumor cells with chemo-resistance, aggressive dissemination, and early relapse, we hope to design an anti-SIAH-centered anti-K-RAS/EGFR targeted therapy as a novel therapeutic strategy to control and eradicate incurable TNBC in the future.

Abstract 2145: Detect early tumor relapse in high-risk breast cancer

Chemotherapy resistant breast cancer is a major health challenge, resulting in high relapse rates and poor survival. Neoadjuvant chemotherapy (NACT) is a standard treatment for women with high-risk TNBC, HER2+, and locally advanced ER+ breast cancer. A completed course of NACT results in two possible outcomes: pathologic complete response (pCR) or residual disease. While pCR is a reliable clinical prognostic biomarker associated with excellent outcomes and prolonged survival, especially for TNBC and HER2+ cancers, patients with residual disease have a higher risk of recurrence. Patients with residual disease can be further stratified clinically using the Residual Cancer Burden (RCB) classification; however, patients with similar RCB classes may experience dramatically different clinical outcomes. Thus, additional precision biomarkers to stratify patients with residual disease after NACT are needed to identify patients at highest risk of recurrence, and to develop new therapeutic strategies to eradicate multidrug-resistant tumors.

Supported by strong evidence in developmental, evolutionary and cancer biology, we found that K-RAS-SIAH pathway activation is a major tumor driver, and SIAH represents a key tumor vulnerability in breast cancer. Normal K-RAS/SIAH signaling pathway activation is indispensable for proper cell-cell communication, cell proliferation and tissue homeostasis in multicellular organisms. However, abnormal K-RAS/SIAH pathway activation is highly prevalent in high-risk and locally advanced breast cancer, and may confer chemo-resistance to these high-risk mammary tumors. Based on its evolutionary conservation and significance as the most downstream signaling module indispensable for K-RAS signal transduction, SIAHON/OFF expression is a reliable readout of K-RAS/EGFR/HER2 pathway activation/inactivation. We showed that SIAHON/OFF expression is a binary code in residual mammary tumors that can be used to stratify patients, augment RCB classification, forecast tumor relapse, and predict patient survival after 1st line NACT in a pilot retrospective study.

Multidrug-resistant high-grade breast cancer is a genetically diverse, highly heterogeneous disease that challenges our ability to individualize and optimize precision therapy. Persistent K-RAS-SIAH-EGFR pathway activation endows TNBC with therapy resistance, and increases the risk of metastasis and early relapse. As such, we developed a K-RAS/SIAH-centered biomarker discovery program and a new anti-SIAH research initiative with the intended goal of designing novel and potentially life-saving anti-K-RAS targeted strategies to control and eradicate multidrug-resistant and intractable mammary tumors.

Citation Format: Amy H. Tang, Lauren L. Siewertsz van Reesema, Vasilena P. Zheleva, Janet S. Winston, Rick J. Jansen, Emanuel F. Petricoin, Matthew P. Goetz, Matthew P. Goetz, Harry D. Bear, Richard A. Hoefer. Detect early tumor relapse in high-risk breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2145.

RAS pathway biomarkers for breast cancer prognosis

Metastatic breast cancer is a highly heterogeneous, rapidly evolving and devastating disease that challenges our ability to find curative therapies. RAS pathway activation is an understudied research area in breast cancer. EGFR/RAS pathway activation is prevalent in breast cancer with poor prognosis. The prognostic RAS pathway biomarkers can be used to identify resistant tumour clones, stratify patients and guide therapies.

SIAH and EGFR, Two RAS Pathway Biomarkers, are Highly Prognostic in Locally Advanced and Metastatic Breast Cancer

BACKGROUND

Metastatic breast cancer exhibits diverse and rapidly evolving intra- and inter-tumor heterogeneity. Patients with similar clinical presentations often display distinct tumor responses to standard of care (SOC) therapies. Genome landscape studies indicate that EGFR/HER2/RAS "pathway" activation is highly prevalent in malignant breast cancers. The identification of therapy-responsive and prognostic biomarkers is paramount important to stratify patients and guide therapies in clinical oncology and personalized medicine.

METHODS

In this study, we analyzed matched pairs of tumor specimens collected from 182 patients who received neoadjuvant systemic therapies (NST). Statistical analyses were conducted to determine whether EGFR/HER2/RAS pathway biomarkers and clinicopathological predictors, alone and in combination, are prognostic in breast cancer.

FINDINGS

SIAH and EGFR outperform ER, PR, HER2 and Ki67 as two logical, sensitive and prognostic biomarkers in metastatic breast cancer. We found that increased SIAH and EGFR expression correlated with advanced pathological stage and aggressive molecular subtypes. Both SIAH expression post-NST and NST-induced changes in EGFR expression in invasive mammary tumors are associated with tumor regression and increased survival, whereas ER, PR, and HER2 were not. These results suggest that SIAH and EGFR are two prognostic biomarkers in breast cancer with lymph node metastases.

INTERPRETATION

The discovery of incorporating tumor heterogeneity-independent and growth-sensitive RAS pathway biomarkers, SIAH and EGFR, whose altered expression can be used to estimate therapeutic efficacy, detect emergence of resistant clones, forecast tumor regression, differentiate among partial responders, and predict patient survival in the neoadjuvant setting, has a clear clinical implication in personalizing breast cancer therapy.

FUNDING

This work was supported by the Dorothy G. Hoefer Foundation for Breast Cancer Research (A.H. Tang); Center for Innovative Technology (CIT)-Commonwealth Research Commercialization Fund (CRCF) (MF14S-009-LS to A.H. Tang), and National Cancer Institute (CA140550 to A.H. Tang).