Over recent decades, the incidence of cancer and the mortality that it causes have increased in developing countries such as Brazil. 1 Among all neoplasms, lung cancer presents major concern because it is a relatively frequent disease (i.e. the fourth most common type of cancer in Brazil) and presents high lethality. In Brazil, 28,220 new cases were expected in 2017; almost 25,000 were recorded in 2013. 2 Studies on the molecular biology of advanced non-small cell lung cancer (NSCLC) have led to development of directed targeted therapies that have demonstrated better clinical outcomes and fewer collateral effects, compared with platinum-doublet chemotherapy. 3-5 Epidermal growth factor receptor (EGFR) is a transmembrane receptor that conducts signals to promote cell proliferation, angiogenesis and cell immortality. 6 Treatment of advanced NSCLC with tyrosine kinase inhibitors (TKI) directed against the EGFR receptor leads to a response rate of over 50% (that of chemotherapy is approximately 35%), and a nearly 100% increase in median progression-free survival, compared with platinum-doublet chemotherapy. 3-5 On the other hand, no studies have demonstrated any increase in overall survival, compared with platinum-doublet chemotherapy, due to the high rate (about 70%) of treatment crossover between the arms of these studies. In other words, the majority of individuals included in such clinical studies received anti-EGFR TKI in first-line or second-line treatment. 3-5