Abstract 4943: microRNAs as clinical biomarkers for lung cancer classification

Background: Lung cancers have traditionally been subdivided into two main groups: Small Cell Lung Cancer (SCLC) and Non Small Cell Lung Cancer (NSCLC). Due to limited tumor sample amounts and an abundance of poor quality samples, accurate subclassification of primary lung cancer using small pre-operative biopsies presents a diagnostic challenge using current tools (H&E and immunohistochemical stains). For patients with primary lung cancer, accurate determination of the tumor type significantly influences treatment decisions. Our previous studies have shown that microRNAs are differentially expressed in different subtypes of lung cancer; hence microRNA expression profiling holds a promising new strategy for the precise subclassification of lung cancers. Based on these findings, we present here the development of a microRNA-based qRT-PCR diagnostic assay that uses pathology and cytology samples in order to classify primary lung cancers into four subtypes: squamous, non-squamous, SCLC and carcinoid. Methods: FFPE tissue blocks and cell blocks from different histological subtypes of lung cancer, taken from primary lung cancer resection or pre-operative diagnostic procedures, were collected. High-quality RNA, including the well-preserved microRNA fraction, was extracted from the samples using proprietary protocols. Expression levels of potential microRNA biomarkers were profiled using a sensitive and specific qRT-PCR platform. Results: We find that combinations of a few microRNAs can successfully differentiate between different histological types of lung tumors. A classification algorithm was developed that reached high accuracy in the identification of the four main subtypes of lung tumors. Conclusion: We developed a highly accurate microRNA-based diagnostic assay that classifies primary lung cancer types with very high sensitivity and specificity. This assay is a simple and reliable diagnostic assay which will offer an accurate and standardized tool for primary lung cancer cytological samples, including those that presently fail pathological evaluation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4943. doi:10.1158/1538-7445.AM2011-4943