Abstract 2360: A novel auto-antibody test for the detection of pre-neoplastic lung lesions.

Abstract

Abstract Atypical adenomatous hyperplasia (AAH) and squamous cell dysplasia (SCD) have been widely reported to be associated with the development of malignant lesions in the lung. Accurate diagnosis of AAH and SCD could facilitate earlier clinical intervention and also provide useful information for assessing lung cancer risk in human populations. Traditionally, detection of AAH and SCD has been achieved by imaging and bronchoscopy, but the sensitivity remains unsatisfactory. In this study, we utilised the ability of the immune system to identify lesion specific proteins for detection of AAH and SCD. We have successfully used serum auto-antibody panels as biomarkers for the detection of malignant lung lesions [Zhong 2006] and thus, a similar approach was utilised here for the development of a blood-based test for the detection of AAH and SCD. Following informed consent and Internal Review Board approval, AAH and SCD tissue was surgically removed from six patients of Chinese descent (3 AAH and 3 SCD) with corresponding serum samples. Total RNA was extracted from the tissues and a cDNA library was generated and incorporated into a T7 bacteriophage vector. To enhance the selection of tumor-associated proteins, the AAH and SCD pooled phage library was biopanned using pooled AAH/SCD and normal sera, and candidate phage clones were subjected for two-color fluorescent protein microarray construction. Cy3-labelled antibodies were used as a control for the detection of phage capsid proteins and Cy5-labelled anti-human antibodies were used to probe for AAH/SCD proteins. A total of 200 AAH related and 200 SCD related phage clones that revealed stronger Cy5:Cy3 ratios from 5 individual AAH and 5 SCD serum reactions were chosen as candidates for statistical classifier development. Microarray slides were tested with 50 AAH and 50 SCD patient serum samples along with 100 control serum samples as a training group for statistical classifier development. Nine AAH-associated phage proteins were identified and used to develop a classifier with 92.3% sensitivity and 90.2% specificity in distinguishing AAH samples. Thirteen SCD-associated markers were identified that generated a classifier with 98.3% sensitivity and 95.6% specificity in distinguishing SCD samples. The classifiers were further validated in an independent blinded sample population consisting of 100 AAH, 100 SCD and 200 control serum samples. In this cohort, 82% sensitivity and 70% specificity was achieved in the detection of AAH samples using a combination of 9 autoantibody biomarkers. Likewise, 86% sensitivity and 78% specificity was achieved in the detection of SCD samples using a combination of 13 SCD-associated markers. Both diagnostic values reached much greater accuracies than any other current biomarkers for AAH or SCD and hence could be a useful tool to assess lung cancer risk in human populations. Citation Format: Frazer Lowe, Xufei Zhang, Hao Wang, Jinchi Zu, Weike Shen, Li Zhong. A novel auto-antibody test for the detection of pre-neoplastic lung lesions. [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 2360. doi:10.1158/1538-7445.AM2013-2360