> Research & Grants
> Grants Program
> Research Grants
> Research Grants Awarded
Clinical Utility of Hypermethylated Genes in Primary Tumors and Body Fluids as Prognostic Markers of Breast Cancer Patients
BACKGROUND: Improvement in breast cancer screening have resulted in a dramatic increase in the detection of early primary breast cancer. Furthermore sentinel lymph node biopsy has provided a minimally invasive and focused approach for identification of early regional tumor dissemination. Unfortunately, despite these advances up to 30% of early stage breast cancer patients will into develop systemic metastasis. Consequently additional methods are needed to better predict disease outcome and follow up patients. There is convincing evidence demonstrating the presence of significant levels of epigenetic alterations in breast cancer. Epigenetic alterations such as aberrant hypermethylation of CpG island motifs in promoter regions of tumor-suppressor and regulator genes that results in silencing gene expression have been found in breast cancer. This frequent type of aberration may have potential as a genetic signature of disease progression and outcome. Analysis of these markers also offers the capability of utilizing paraffin-embedded microdissected tissue instead of fresh/frozen tissue in which the latter are often logistically problematic to assess. The detection of tumor identified methylated DNA markers circulating in blood and bone marrow may provide a novel approach detecting disease progression. Our strategy is to identify these methylated DNA markers of tumor-related genes in primary tumors, acellular sera and bone marrow as disease outcome predictors alone or with known clinicopathological prognostic factors.
HYPOTHESIS: Our main hypothesis is that identification of specific epigenetic markers such as hypermethylated DNA of tumor-related genes in primary breast tumor can be used as predictors of metastasis and disease outcome. The second hypothesis is that circulating hypermethylated DNA markers of tumor-related genes can be detected in acellular serum and bone marrow, and be utilized for serial genetic analysis for monitoring disease progression.
SPECIFIC AIMS: Aim I, Identification of hypermethylated DNA markers of tumor-related genes using a quantitative methylation specific PCR (MSP) assay in primary breast tumors that is predictive for metastatic status and overall disease-outcome. Aim II, Assessment of hypermethylated DNA markers identified in Aim I that are present in circulating tumor cells in blood and bone marrow of early stage breast cancer patients. The objective is to identify hypermethylated DNA markers of systemically spreading tumor cells in body fluids that are highly likely in developing into aggressive metastasis in distant organs. Aim III, Assessment of acellular serum for the presence of specific hypermethylated DNA markers to identify their potential clinical utility as predictive surrogate markers of disease progression.
STUDY DESIGN: The studies in Aim I will be a retrospective study utilizing paraffin-embedded primary breast tumor of patients with different AJCC stages followed up >5 years. Aims II and III will involve assessing archival paired blood and bone marrow specimens of the primary tumors in Aim I. Predictive hypermethylated DNA markers developed in our laboratory for breast cancer will be assessed by a sensitive quantitative methylation-specific PCR assay.
POTENTIAL OUTCOMES AND BENEFITS OF THE RESEARCH: If successful the study will identify epigenetic markers as predictors of disease outcome thus allowing for better patient management. Identification of genetic changes of the primary tumor that reflects the "metastatic state" and potential disease outcome would limit the extent of surgery and serve as a valuable risk stratification factor. The development of a serial genetic assay for body fluids will be highly valuable for surveillance of disease recurrence and treatment monitoring.
BACKGROUND: Advances in screening mammography and greater public awareness has resulted in a dramatic increase in the detection of early breast cancers. Nevertheless still too many women are dying from recurrent disease who were without evidence of tumor dissemination at the time of initial diagnosis and treatment. These findings suggest that occult metastasis were present at the outset but not identified by conventional detection methods. Therefore, newer approaches are urgently needed in this era for better informative analysis of earlier stages of disease to identify patients at increased risk for disease recurrence. Recently identified epigenetic DNA alterations of specific genes (i.e. gene hypermethylation) resulting in silencing of gene expression has been associated with cancer development and progression. Assessment of these genetic alterations in primary breast tumors may serve as signatures for predicting disease outcome. We have developed quantitative assays to assess archival fixed (paraffin) tumor tissue and body fluids (blood and bone marrow) for these epigenetic markers.
HYPOTHESIS: Our hypothesis is that specific epigenetic DNA markers of primary breast tumors are predictive of disease progression in early stage breast cancer. Our second hypothesis is that identification of epigenetic tumor DNA markers circulating in free-form blood and bone marrow can be used to effectively monitor early disease progression without tumor analysis.
SPECIFIC AIMS: The principal aim is to identify characteristic epigenetic DNA marker patterns in primary breast tumor that predict for the presence of early metastasis and disease outcome. In this aim we will analyze retrospectively collected archival paraffin-embedded tissue which avoids the logistical limitations associated with fresh/frozen tissue analysis and the lack of long-term clinical results. The assays innovation is the quantitative, rapid, and minimal amount of specimen needed. Aim two is to identify those markers identified in aim I in circulating breast cancer cells in blood and bone marrow. This will tell what is genetically unique about tumor cells that spread in the body. This approach would provide promising highly specific targets tailoring molecular surveillance to an individual patient. The final aim would be to utilize our quantitative assay for assessing these epigenetic DNA markers “circulating” in free form in blood as markers for early disease recurrence and tumor progression. This would allow for utilization of a blood test highly specific for the patient’s own tumor for routine monitoring.
STUDY DESIGN: For Aim I our center is uniquely suited to accomplish this task having a repository of >1000 primary breast cancers with a comprehensive database of matching clinicopathologic prognostic parameters collected from patients. We have a large archival collection of paired blood, bone marrow and tumor tissue, which is a unique resource. Our established quantitative and sensitive molecular assays will be used for the studies outlined.
POTENTIAL OUTCOMES AND BENEFITS OF THE RESEARCH: This systematic assessment of the prognostic utility of epigenetic DNA markers in breast tumors will provide a radical new approach for the evaluation of patients in this new era of breast cancer diagnosis. Potential advantages include a unique approach to predict disease outcome. The development of a highly specific tumor genetic blood assay will help in identifying early disease progression. Success of these findings would clearly shift the cancer care paradigm currently based on conventional methods of tumor staging to a more informative molecular/genetic approach.