Clinical Application of Epidermal Growth Factor Receptor–Tyrosine Kinase Inhibitors against Non-Small Cell Lung Cancer

MedUnion submitted, created time 1 year 8 months (www.mupnet.com)

Single-agent epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib or erlotinib, have a response rate of 20-30% against NSCLC in East Asians who have received prior chemotherapy, while the response rate was only ~10% in unselected white patients. In addition to East Asian populations who have a higher response rate, the response rates are higher in women, persons with adenocarcinoma, and those who have never smoked. These findings can be partly explained by the higher incidence of EGFR mutations in these groups of patients with NSCLC. However, whether or not EFGR protein overexpression, gene amplification, and/or mutation can predict a patient’s response to the treatment or the survival benefit is still controversial. It seems that a high EGFR copy number is more important in predicting response and survival to EGFR-TKI treatment, while EGFR mutation is only significant in predicting response to EGFR-TKI in Caucasian populations; mutation could also be a prognostic factor for East Asian patients. However, further prospective studies are needed before conclusions can be drawn. Studies of EGFR-TKIs, both gefitinib and erlotinib, in combination with platinum-based combination chemotherapy in chemo-naïve, advanced NSCLC, have failed to improve survival. Better characterization of the treatment group, such as those with an EGFR mutation or amplification, and better understanding of interactions between EGFR-TKIs and chemotherapeutic agents, will be essential in the development of more effective strategies. First-line treatment of selected patients with an EGFR mutation or amplification with EGFR-TKI alone or in combination with chemotherapy should be investigated.

Keywords: carcinoma non-small cell lung chemotherapy epidermal growth factor receptor tyrosine kinase inhibitor