Sequential treatment with first-generation tyrosine kinase inhibitor and osimertinib in patients with EGFR mutation-positive advanced non-small-cell lung cancer

Objective To analyze the effectiveness of sequential first-generation tyrosine kinase inhibitor(TKI)and osimertinib on epidermal growth factor receptor(EGFR)mutation-positive advanced non-small-cell lung cancer. Methods A total of 99 patients with EGFR mutation-positive non-small cell lung cancer(NSCLC)treated with sequential first-generation epidermal growth factor receptor tyrosine kinase inhibitor(EGFR-TKI)and osimertinib in the first medical center of Chinese PLA General Hospital from March 2010 to November 2018 were enrolled.There were 37 males and 62 females with an average age of 56(28-80)years.The patients' basic characteristics,disease characteristics,treatment and survival were analyzed,and the treatment effect was evaluated. Results The median progression-free survival(PFS)of 99 patients was 26.4 months(95% confidence interval:23.1 to 29.6),and the objective response rate(ORR)was 62.6%.Patients treated with first-generation TKI for more than 10.1 months had a significant prolongation of PFS after sequential osimertinib treatment(16.4 months v.s 7.1 months,P=0.004). Conclusion The PFS of patients treated with first-generation TKI for more than 10.1 months following osimertinib is longer than patients with first-generation TKI treated ≤ 10.1 months.