Published online Dec 10, 2014. doi: 10.5306/wjco.v5.i5.858
Revised: July 19, 2014
Accepted: October 1, 2014
Published online: December 10, 2014
Processing time: 222 Days and 1.6 Hours
Erlotinib and gefitinib are among the most widely researched, used and available molecularly targeted therapies for treatment of advanced non-small cell lung cancer (NSCLC). They are both tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR). In the past decade, there have been reports on clinical benefit from use of erlotinib after gefitinib failure in NSCLC patients. A review of published literature on this focussed topic is provided herein. Pooled analysis of published literature shows that majority of patients were female (60.6%), non-smokers (64.5%), had adenocarcinoma histology (88.3%) and were of East Asian ethnicity (92.3%). Presence of sensitizing EGFR mutation was detected in 48.4% of subjects. Disease control rates with prior gefitinib therapy and with subsequent erlotinib treatment were 79.4% and 45.4% respectively. Based upon our review, the most important predictive factor for clinical benefit from erlotinib identified was previous response to gefitinib. The exact explanations for the potential benefit from erlotinib use in this patient population is still not known and further studies are required to determine the role of molecular mechanisms especially those related to resistance to initial EGFR TKI therapy.
Core tip: This manuscript is focused on the controversial yet interesting topic of whether erlotinib provides clinical benefit amongst patients who have experienced disease progression after prior therapy with gefitinib-both drugs being tyrosine kinase inhibitors of the epidermal growth factor receptor. We have reviewed available literature on this topic, carried out a pooled analysis on available data and hope readers find it useful in clearing the confusion related to this topic.