Abstract 1165: Measuring telomere length for the early detection of precursor lesions of esophageal squamous cell carcinoma.

Abstract

Abstract Objectives: Esophageal cancer is the fifth leading cause of cancer death worldwide. The five-year survival is approximately 16%. Patients can be successfully treated if diagnosed early, but current early detection screening tests are inadequate. Balloon cytology is a simple and inexpensive method of retrieving esophageal cells, but traditional cytologic examination of these cells has poor sensitivity and specificity. We examined whether telomere length, a marker for chromosomal instability, in DNA extracted from balloon cytology-collected esophageal cells is associated with precursor lesions of esophageal squamous cell carcinoma. Methods: The Cytology Sampling Study 2, a population-based esophageal cancer early detection screening study, recruited over 700 healthy subjects from a high-risk population in Linxian, China. The screening study used a mesh-covered balloon to collect esophageal cells. All subjects underwent endoscopy, and precursor lesions were diagnosed by biopsy. Using a nested case-control study design, we examined the association between telomere length and dysplasia in 37 low-grade dysplasia cases, 52 high-grade dysplasia cases, and 92 matched controls. DNA was extracted from cells collected by balloon cytology, and telomere length was measured in triplicate by a quantitative PCR assay. Logistic regression models adjusted for age, sex, smoking tobacco, alcohol intake, and hypertension were used to examine the association between telomere length and risk of low-grade dysplasia and high-grade dysplasia, compared with normal controls. Results: Telomere lengths were comparable among the low-grade dysplasia cases, high-grade dysplasia cases, and controls, with a median of 0.93 [interquartile range (IQR), 0.84-1.06], 0.94 (IQR, 0.82-1.09), and 0.93 (IQR, 0.78-1.05), respectively. Overall, telomere length was not associated with risk of low-grade dysplasia or high-grade dysplasia, with an odds ratio [OR, 95% confidence interval (CI)] of 1.16 (0.87-1.54) and 1.20 (0.92-1.56), respectively. Conclusions: Given that esophageal cancers have very poor prognoses, it is of utmost importance to improve early detection. In this study, esophageal cell telomere length was not associated with esophageal precursor lesions and cannot serve as an early detection marker. Citation Format: Shih-Wen Lin, Christian C. Abnet, Neal D. Freedman, Rosana Risques, Donna Prunkard, Peter Rabinovitch, Ning Lu, You-Lin Qiao, Sanford M. Dawsey. Measuring telomere length for the early detection of precursor lesions of esophageal squamous cell carcinoma. [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 1165. doi:10.1158/1538-7445.AM2013-1165