Role of molecular examinations in qualification to first line treatment with erlotinib in NSCLC patients based on EUTARCstudy results Review article

Abstract

Between 2010–2011 the first EGFR thyrosine kinase inhibitor (EGFR TKI) – gefitinib, was registered in many countries in I line of treatment in patients with advanced and locally advanced non-small cell lung cancer (NSCLC), among whom EGFR gene mutations have been detected. It was also found that the presence of these mutations is crucial for the effectiveness of EGFR TKI – erlotinib, used so far mainly in monotherapy in II line in NSCLC patients, with unknown EGFR gene status. Studies of these two drugs concerned mostly Asian NSCLC populations, where EGFR gene mutations occurrence is much higher than in Caucasian populations. The EURTAC study, and a study by Rosell et al. previous to it, were the first ones that confirmed the effectiveness of erlotinib in adenocarcinoma patients of Caucasian origin, who carried EGFR gene mutations: exon 19 deletions or L858R substitution in exon 21 of this gene. The innovative nature of this study is to attempt to detect EGFR gene mutations in free circulating DNA in peripheral blood, which could broaden the possibility of advanced NSCLC patients qualification to EGFR TKI treatment. The EURTAC study also has its weaknesses, among which disqualification of patients with other forms of non-squamous NSCLC (e.g. large cell carcinoma patients, who also might be carriers of EGFR gene mutations) and patients with rare EGFR gene mutations, are the most distinct.