Abstract: Objective To investigate the effects of pretreatment serum carcinoembryonic antigen（CEA）on the efficacy and survival of tyrosine kinase inhibitors （TKIs） in the EGFRmutant patients with advanced lung adenocarcinoma. Methods The clinical data of 120 patients with EGFR mutant advanced lung adenocarcinoma treated with gefitinib， erlotinib or icotinib hydrochloride at our department between December 2005 and April 2013 were retrospectively reviewed， and influencing factors of response and survival were analyzed. Differences in efficacy between variables were evaluated using the Response Evaluation Criteria in Solid Tumors（RECIST） （version 1.1）. Progression free survival（PFS）and overall survival（OS） were estimated by the KaplanMeier method. Independent risk factors were assessed in multivariate analysis using the Cox proportional hazards model.
ResultsThe response rate（RR） and disease control rate（DCR） were 57.5％ and 94.2％， respectively， the median PFS was 9.0 months（95%CI：7.91-10.09 months） and median OS was 23.5 months（95%CI：17.89-29.11 months）. The pretreatment serum CEA level was positive （≥5 ng／ml） for 44.2％ of the patients. Neither the RR to TKIs （55.2％ vs. 60.4％， P=0.5721） nor PFS（10.0 months vs. 8.0 months， P＞0.05） had significant differences between the two groups of CEA＜5 ng／ml and CEA≥5 ng／ml. The median OS of patients with CEA＜5 ng／ml was significantly better （30.0 months vs. 17.2months， P=0.022）. A multivariate analysis indicated smoking， serum CEA and PS performance scoring to be independent prognostic factors. Conclusion It shows that the serum CEA＜5 ng／ml may not be a predictive factor for the efficacy of EGFRTKIs， but it is a positive prognostic factor for EGFR mutant advanced lung adenocarcinoma patients undergoing this treatment.