Abstract 3477: Discovery and validation of methylation markers for early detection of endometrial cancer.
Authors: Wentzensen Nicolas A. , Bakkum Jamie , Killian Keith , Shridhar Viji , Adams Lisa , Guido Richard , D'Ambrosio Lori , Luhn Patricia , Sampson Joshua , Yang Hannah , Brinton Louise , Lissowska Jolanta , Podratz Karl , Sherman Mark 
Published: August 2014

Background: Endometrial cancers account for over 46,000 cases and 8,100 deaths annually in the U.S. Endometrial cancers that are confined to the uterus portend an excellent prognosis, suggesting that development of early detection methods for these tumors could reduce mortality. To identify and validate markers with potential utility in early detection of endometrial cancers, we compared DNA methylation profiling data for endometrial cancer tissues collected in a population-based epidemiological study and a comparison set of benign endometrial tissues, and replicated promising candidates in a separate clinical study.

Methods: We used the Illumina Golden Gate platform to profile DNA methylation of CpGs at 1536 sites (807 genes) using fixed tissues from 148 endometrial cancers included in the population-based Polish Endometrial Cancer Study (cases) and 23 benign endometrial tissues collected at Magee Women's Hospital (controls). Tissue cores (1.0-mm) removed from target-rich areas of blocks were used for DNA extraction, bisulfite treatment and profiling. We replicated top candidate markers by applying pyrosequencing assays to endometrial brushings performed prior to hysterectomy among 38 women with endometrial cancer and 37 with benign gynecological diseases treated at the Mayo Clinic and calculated odds ratios comparing the highest tertile of methylation values in controls for each marker with middle and low tertiles. In addition, we assessed discrimination across the whole range of cutoffs using Receiver Operator Characteristics (ROC) curves.

Results: Methylation profiling identified 114 CpG sites with differential methylation levels between cases and controls (P≤10-7). Eight genes (ADCYAP1, ASCL2, HS3ST2, HTR1B, MME, NPY, and SOX1) which showed large case-control differences in methylation levels (≥ 0.4), and low values in controls (&lt;0.2) were chosen for replication by pyrosequencing in pre-hysterectomy patients. In the replication study, higher methylation levels were found for 7 of 8 genes in endometrial brush samples from women with cancer as compared to women without cancer. In the replication study, odds ratios for association of methylation markers with endometrial cancer ranged from 3.6 (95%-CI: 1.35-9.47) for HTR1B to 10.9 (95%-CI: 3.23-36.91) for ASCL2. Discrimination of cases and controls was best for ADCYAP1 (area under ROC curve=0.89; 95% CI: 0.80-0.97), CDH13 (0.87; 95% CI: 0.80-0.97), and MME (0.87; 95% CI: 0.78-0.97).

Conclusions: Analysis of DNA methylation markers in endometrial brushings is strongly associated with prevalent endometrial cancer at hysterectomy. Development and validation of a robust early detection marker panel for endometrial cancers, including non-endometrioid cancers and precursor lesions is ongoing.

Citation Format: Nicolas A. Wentzensen, Jamie Bakkum, Keith Killian, Viji Shridhar, Lisa Adams, Richard Guido, Lori D'Ambrosio, Patricia Luhn, Joshua Sampson, Hannah Yang, Louise Brinton, Jolanta Lissowska, Karl Podratz, Mark Sherman. Discovery and validation of methylation markers for early detection of endometrial cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3477. doi:10.1158/1538-7445.AM2013-3477