Abstract 403: The landscape of PD-L1 expression in lung cancer harboring EGFR mutations

Abstract

Abstract Background: Results from previous studies indicated that lung cancer patients harboring EGFR sensitizing mutations may receive unfavorable outcomes from immunotherapy. The present study aims to investigate the landscape of PD-L1 expression in lung cancer harboring EGFR mutations. Methods: Tissue samples were subjected to NGS in a College of American Pathologists-certified and Clinical Laboratory Improvement Amendments-accredited lab for driver oncogene mutations and PD-L1 expression. Results: A total of 22143 lung cancer patients were selected, including 12278 (55.4%) male and 9865 (44.6%) female with a median age of 63. There are 9560 patients has the EGFR mutation, and the frequency of EGFR mutation is 43.2%. Among the EGFR mutation patients, 1602 patients have been collected tumor tissue, and the PD-L1 expression have been tested by FDA-approved SP263 and 22C3 antibodies. Among all the EGFR mutation cases assessed PD-L1 expression (n=1602), low PD-L1 expression levels (<1%) were more than half proportion with 56.5% (n=905), PD-L1 expression level of 1%-49% accounted for 31.2% (n=905), PD-L1 expression level of 50%-79% accounted for 9.1% (n=146), PD-L1 expression level of 80%-89% accounted for 1.8% (n=29), and PD-L1 expression level higher than 90% accounted for 1.4% (n=22). Conclusion: Our study supported that NSCLC patients harboring sensitizing oncogenic mutations may potentially benefit from anti-PD-1/L1 especially for those with positive indicators of immunotherapy with strong positive PD-L1 expression. Citation Format: Linlin Zhang, Fuyu Gong, Fanlu Meng, Xin Wang, DianSheng Zhong. The landscape of PD-L1 expression in lung cancer harboring EGFR mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 403.