The impact of clinical parameters on progression-free survival of non-small cell lung cancer patients harboring EGFR-mutations receiving first-line EGFR-tyrosine kinase inhibitors

Abstract

Objectives: In daily practice, some patients with certain clinical characteristics may have better responses to the administration of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). It is therefore reasonable to stratify and weigh the importance of these clinical parameters which may not only affect patients' responses to TKIs but also progression-free survival (PFS) other than the impact of EGFR mutation status per se.

Materials and methods: This retrospective study evaluated EGFR-mutant, non-small cell lung cancer patients who received EGFR-TKIs as a first-line therapy between January 2011 and December 2013. Several potential prognostic factors were analyzed with respect to PFS, and the results of this analysis were validated in another time cohort.

Results: A total of 262 patients were included in the study. Age ≤ 40 years, uncommon EGFR mutations, poor performance status, more sites of distal metastasis, and blood lymphocyte to monocyte ratio ≤ 3 were independently associated with poor PFS. These five factors were included in a scoring system and three prognostic groups A, B, and C, were formed based on total scores of 0-1, 2, and ≥ 3, respectively. In the test group, the PFS was 15.7 month, 9.3 month, and 4.0 month in groups A, B, and C, respectively (p<0.001). Between the test and validation groups, no significant differences were found in each one of the three prognostic groups.

Conclusions: The scoring system appears valid and reproducible for PFS prognosis in EGFR-mutant patients who received first-line EGFR-TKIs.

Keywords: Epidermal growth factor receptor; Non-small cell lung cancer; Progression-free survival; Scoring system; Tyrosine-kinase inhibitors.