e20571 Background: Lung adenosquamous cell carcinoma (ASC) is a rare subtype of lung cancer. Little is known about the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) for lung ASC with EGFR mutation. Methods: We retrospectively analyzed 44 patients with advanced or recurrent lung ASC harboring EGFR mutation who were treated with EGFR-TKI from two cancer centers to investigate the efficacy. Then a pooled analysis on the efficacy of EGFR-TKI was performed in 74 patients including 30 patients selected from 11 published reports. Results: In our bicenter research, for the ASC patients treated with EGFR-TKI, the objective response rate (ORR), the disease control rate (DCR), the median progression free survival (mPFS) and the median overall survival (mOS) were 54.5%, 79.5%, 8.8 months and 19.43 months, respectively. In pooled analysis, the ORR, DCR, mPFS and mOS of ASC patients were 63.4%, 85.9%, 10.00 months and 21.37 months, respectively. Similar PFS (11.0 vs. 10.0 months; P= 0.771) and OS (23.67 vs. 20.33 months; P= 0.973) were found in patients with deletion in exon 19 and exon 21 L858R mutation. The patients treated with erlotinib or gefitinib had a trend of better OS than those treated with icotinib. Conclusions: EGFR-TKI is an effective treatment for ASC harboring EGFR mutation, comparing with historical data, similar to EGFR-mutated adenocarcinoma (ADC). Further study is needed to identify the different role of the two components of ASC in EGFR treatment.
P-252 Residual fibrosis after treatment with anti-epidermal growth factor receptor or bevacizumab in colorectal liver metastases and its correlation with survival: A retrospective pooled analysis