Usage patterns of biomarkers in non-small-cell lung cancer patients in India: Findings from a systematic review and survey

INTRODUCTION: Personalized medicine has facilitated improved management of non-small cell lung cancer (NSCLC) patients by identifying predictive and prognostic biomarkers for enhanced efficiency of detection and efficacy of treatment. This systematic review and survey assessed the patterns of biomarker usage, molecular testing techniques to diagnose patients with NSCLC in India and testing techniques recommended by cancer societies. MATERIALS AND METHODS: Studies were retrieved from Embase, PubMed, and Cochrane databases for the last 12 years, using relevant search strategies as per the Cochrane methodology for systematic reviews. Outcomes of interest were biomarkers for NSCLC, patterns of biomarker testing, diagnostic methods, guidelines and cost of biomarker testing. RESULTS: In all, 499 studies were identified for screening and 17 primary publications were included in the review. Epidermal growth factor receptor (EGFR) expression and epithelial markers (particularly cytokeratins (CK)) were the most commonly reported biomarkers (7/17) and immunohistochemical (IHC) staining was the most common technique for detection of biomarkers. The frequency of EGFR mutations was higher among women than men. Significantly elevated levels of CK-18 were observed in patients with squamous cell carcinoma and of CK-19 in patients with adenocarcinoma, squamous cell carcinoma, and NSCLC (P < 0.001). Prognostic or predictive role of cytokines and angiogenic markers as well as DNA expression were evaluated. The survey also showed that IHC was the most common technique for detection of biomarkers. CONCLUSIONS: This systematic review and survey provides valuable information on biomarker usage in the Indian population, and highlights the need for initiatives required for future biomarker testing in India.