Journal of Clinical & Experimental Pathology
Open Access

Abstract

Recent clinical screening trials using highly sensitive low-dose computed tomography (LDCT) demonstrated an improved overall survival of lung cancer patients. However, these trials showed high repeat screening rates and high false-positive rates causing unnecessary second-line invasive procedures and surgery. New strategies are needed to improve the specificity of lung cancer screening. Bronchoalveolar lavage (BAL) is commonly used for the cytological evaluation of cells in lung nodules and diagnosis of lung cancers, proteins in the BAL fluid not examined in clinical practice, might serve as biomarkers for cancer diagnosis. We collected sixteen BAL samples, including four cases each of benign lung disease, adenocarcinoma (ADC), squamous cell carcinoma (SqCC), and small cell carcinoma (SCLC), and studied protein profiles using the solid-phase extraction of N-glycoprotein (SPEG) and liquid chromatography tandem mass spectrometry (LC-MS/MS). A total of 1013 unique peptides from 457 glycoproteins were identified and quatified. Among them, 286 proteins were identified in BAL of ADC, 363 in squamous cell carcinoma (SqCC), 298 in SCLC and 330 in benign BALs. In addition to common proteins found in all groups, we identified 113 unique proteins that were differentially expresssed exclusively in either benign disease, ADC, SqCC or SCLC. The levels of four proteins in cancer and benign BALs were further validated using independently collected 117 BAL specimens by ELISA assays. Our study demonstrates that proteins in BAL fluid have the potential to be used as biomarkers to improve the specificity of lung screening tests and the early detection of lung cancers.

Biography

Qing Kay Li is an American Board of Pathology certified pathologist and an Associate Professor of the Department of Pathology at the Johns Hopkins Medical Institutions. In addition to clinical service, her research effort is focused on the early detection of lung and prostate cancers. She has published more than 50 papers in peer-reviewed journals and served in study sections for reviewing grant applications. She also serves as editorial board member of journals and committee member of the American Society of Cytopathology.