Abstract A67: Methylation of ESR1 and 14-3-3 sigma promoter in serum as possible biomarkers for screening and diagnosis for breast cancer

Abstract

Abstract Background: To investigate the association between gene hypermethylation and the major clinico-pathological features of breast cancer, including diagnosis and treatment response. Material and Methods: 107 women with breast cancer and 108 control subjects were recruited. Real Time QMS-PCR SYBR green (methylation-specific PCR) was used to analyze the utility of circulating DNA with CpG island hypermethylation of APC, RAR-β, E-Cadherin, ESR1 and 14-3-3 sigma; gene promoter regions as breast cancer biomarkers. Sera were collected in 107 operable breast cancer patients (pts) previously surgery and in 60 of those pts after treatment. Respect controls, 34 had benign breast disease and 74 with no evidence of breast disease. Results: We found significant differences between breast cancer patients and healthy controls in relative serum levels of methylated gene promoters ESR1 (p = 0.0112) and 14-3-3sigma (p=0.0047). We observed that hypermethylation of these combined two genes differentiated between breast cancer patients and healthy controls (p <0.0001) with a sensitivity of 81% (95% CI: 72–88%) and specificity of 88% (95% CI: 78–94 %). Presence of methylated ESR1 in serum of breast cancer patients was associated with ER-negative phenotype (p = 0.0179); and presence of methylated 14-3-3-sigma was associated with T3-4 stage (OMS) (p< 0.05) and nodal positive status (p< 0.05). We observed lower methylated ERS1 or 14-3-3-sigma values after surgery, respect pretreatment levels, but without an overall statistically significant difference. With a median follow up of 6 years, we found that patients with a significant decrease of sera methylated levels of both genes after surgery had better time to progression an overall survival respect patients without this observation. Conclusions: this panel of genes detected in ductal lavage and blood specimens could be useful as markers for early detection of breast carcinoma. These findings cast some doubts on the utility for early cancer diagnosis of highly sensitive techniques to identify hypermethylation of specific gene promoters in DNA extracted from serum. Although numerous issues remain to be resolved, the quantitative measurement of circulating methylated DNA is a promising tool for cancer risk assessment. Note: This abstract was not presented at the conference. Citation Format: Joaquina Martinez-Galan, Blanca Torres-Torres, Juan Ramón Delgado. Methylation of ESR1 and 14-3-3 sigma promoter in serum as possible biomarkers for screening and diagnosis for breast cancer. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A67.