Abstract 4219: Biomarkers of cancer stem cells and invasion can predict breast cancer metastasis
Authors: Stobezki Robert , OKtay Maja , Adler Ester , Gertler Frank , Condeelis John S. , Jones Joan , Goswami Sumanta 
Published: February 2011

Background: Breast cancer mortality is largely attributable to the development of systemic, hematogenous metastatic disease. Although nearly 10-15% of patients have an aggressive form disease that metastasizes within three years after initial diagnosis, the clinical manifestations of metastatic disease can appear ten or more years later. To decrease the risk for the emergence of metastatic tumors, nearly 80% of the patients are treated with adjuvant chemotherapy. The clinical benefit is a 3-10% increase in 15-yr survival, depending upon patient age at diagnosis. Currently established prognostic criteria such as the histopathological grade of the tumor or tumor size do not successfully predict systemic metastatic potential. An enrichment of cancer stem cells in the primary tumor has been shown to be a poor prognostic marker in patients. Epithelial to Mesenchymal Transition (EMT) in breast cancer cells have been shown to give rise to cells that have cancer stem cell like properties. Both of these cells types have been shown to be highly invasive. We have identified invasion markers that can predict EMT, drug and radio resistance in breast cancer cells. In this study we are using biomarkers for cancer stem cells (CD44+/CD24−) and markers of invasion (Mena/Mena11a) to identify cancer initiating cells in Fine Needle Aspiration (FNA). We correlate these ratios with a microanatomical structure called Tumor Microenvironment of Metastasis (TMEM) comprising of a direct apposition of an endothelial cell, a cancer cell and a stromal macrophage in the breast cancer tissue. TMEM has been previously reported to strongly correlate with metastasis.

Hypothesis: The percentage of CD44+/CD24− expression can be used to estimate the number of cancer stem cells in FNA samples. The ratio of Mena to Mena11a protein can be used as a measurement of tumor cell response to the microenvironment and its metastatic phenotype. Measuring the stem cell biomarkers and Mena isoforms in cells collected by FNA biopsy using FACS and combining that with the assessment of TMEM density we will be able to develop a simple, quick and inexpensive method of determining metastatic potential of an individual tumor.

Methods: FNA was conducted on lumpectomy or mastectomy tissues using fine needles, quality of FNA determined by smear staining. Cells were enzymatically digested, fixed and permeabilized. They were then be subjected to flowcytometry analysis using antibodies against stem cell and invasion markers. Rest of the tumor was processed for histopathology and TMEM analysis. Statistical analysis was performed to identify correlation.

Results: Our initial results show that there is a strong correlation between CD44+/CD24− cells in the FNA with TMEM scores. We also report a very high correlation with can also be predicted by the ratios of different splice variants of Mena. This method can be easily used in the clinical setting and applied to a number of different biomarkers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4219.