A Real-world Study On Afatinib As First-line Therapy For NSCLC With Non-classical EGFR Mutations

Objective: To investigate the clinicopathological characteristics,efficacy,side effects and prognostic factors of non-small cell lung cancer patients with non-classical EGFR mutations treated by afatinib.Methods: The data of the patients with non-small cell lung cancer in the second Xiangya hospital of Central South University and Zhu Zhou Second Hospital between 2017 and 2021 was collected.We summarized the clinic features,analyzed the efficacy and toxic effects of afatinib and explored effective prognostic factors.Results:1.A total of 41 NSCLC patients were collected and 27 patients(65.9%)were female,with a male to female ratio of 1:2.21 cases(51.2%)were more than 60 years old,with a median age of 60.0 years old.Most patients were present at IIIB/IV stage at first diagnosis.23 cases(56.1%)were present with single mutation and the most common mutations were exon 21 L861 Q mutation(n=9,21.9%)and exon 18 G719 mutation(n=8,19.5%).The objective response rate was 58.5%(24/41)after treatment.The median follow-up time was 14 months,with a median PFS of 10 months and a median OS of 25 months.The median PFS of NSCLC with single mutation and complex mutation were 10 months,respectively.Treatment-related side effects occurred in 13 patients(31.7%),including diarrhea and skin rash.2.Univariate analysis showed that Ki67≥20% and distant metastasis were adverse prognostic factors,however,distant metastasis was the prognostic factor in multivariate analysis.Conclusion:1.Afatinib was effective in the first-line treatment of advanced-stage patients with non-classical EGFR mutation and the PFS was similar to those with classical mutation,and afatinib was safe.2.Distant metastasis was the prognostic factor in afatinib first-line therapy for NSCLC with non-classical EGFR mutations.