The relationship between preliminary efficacy and prognosis after first-line EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment of advanced non-small cell lung cancer

Background: Nowadays, patients with EGFR tyrosine kinase inhibitor (EGFR-TKI)-sensitive advanced non-small cell lung cancer (NSCLC) receive EGI'R-TKIs as first-line treatment. We aimed to analyze the relationship between preliminary efficacy (tumor shrinkage within 1 month) and progression-free survival (PFS) after first-line EGFR-TKI treatment. Methods: A total of 82 patients with EGFR-TKI-sensitive advanced NSCLC confirmed by histopathology from January 2013 to January 2017 were retrospectively analyzed. All patients received first-line EGFR-TKI treatment and follow-up at Shanghai Chest Hospital. Results: Of a total of 82 patients, 42 (51.2%) patients achieved partial response (PR) within 1 month, and 40 (48.8%) patients achieved stable disease (SD: -30% to 0) within 1 month. The median PFS among all patients was 10 months. The median PFS in patients achieving PR within 1 month was 10.0 months. The median PFS in patients achieving SD (-30% to 0) within 1 month was 9.3 months. There was no statistically significant difference between PR within 1 month and SD (-30% to 0) within 1 month (P=0.620). In the 1-W1 , R-sensitive mutation subgroup, there was also no statistically significant difference between PR within 1 month and SD (-30% to 0) within 1 month. Univariate and multivariate analysis of first-line EGFR-TKI treatment showed that age, EGFR mutation type, and T staging had effects on PFS. Patients who were more than 65 years old, had EGFR 19del mutation, along with a T staging less than 4, had a longer PFS; these differences were statistically significant. Liver metastasis, bone metastasis, and brain metastasis were not shown to be related to PFS. Conclusions: For patients with EGFR-TKI-sensitive advanced NSCLC, there is no correlation between preliminary efficacy (tumor shrinkage within 1 month) and PFS after first-line EGFR-TKI treatment.