A single center study on the relationship between the depth of remission and the efficacy of first-line TKI drugs

Abstract

Objective The aim of the study was to investigate association of response depth and prognosis in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC)patients treated with first-line tyrosine kinase inhibitors (TKIs). Methods The clinicopathological data and prognosis information of patients with locally advanced or metastatic (ⅢB or Ⅳ) lung adenocarcinoma with EGFR classical (19del or 21L858R) mutation who were treated in our hospital from 2015 to 2016 were collected. The tumor remission depth [stable disease (SD), partial response (PR), complete response (CR)] was measured by recist 1.1 standard. The survival curve was drawn by Kaplan-Meier method and log rank test was performed. Results During the study period, 204 advanced lung adenocarcinoma patients with 19del or 21L858R mutation were treated with TKI drugs of the first generation. Among them, 24 patients were lost or unable to evaluate the efficacy, 20 patients were evaluated as progression disease (PD), 62 patients as SD, 98 patients as CR or PR. Disease control rate (DCR) and objective remission rate (ORR) were 88.9% and 54.4%, respectively. The median progression free survival time (PFS) was 12.6 months (95% CI: 10.9-14.4 months) and 13.1 months (95% CI: 11.6-14.7) for patients assessed as SD (group A) and CR or PR (group B), respectively, with no significant difference (P=0.27). Subgroup analysis showed that the median overall survival of patients with EGFR 19del and 21L858R mutations was 12.5 months (95% CI: 9.9-15.4) and 12.7 months (95% CI: 9.4-16.1), respectively, with no significant difference (P=0.66); Similar result was also observed in Group B with a median PFS of 13.9 months (95% CI: 12.3-15.5 months) and 12.3 months (95% CI: 9.5-15.1 months) in patients who had EGFR 19del or 21L858R mutations (P=0.41). Conclusions Response depth was not a positive predictor for prognosis in EGFR-mutant NSCLC patients treated with first-line TKIs. Key words: Lung neoplasms; Receptor, epidermal growth factor; Tyrosine kinase inhibitors; Antineoplastic combined chemotherapy protocols; Response evaluation criteria in solid tumors