e16053 Background: The efficacy of programmed cell death 1 (PD-1) targeted therapy had showed effective treatment in patients (pts) with locally advanced or metastatic esophageal squamous cell carcinoma (ESCC). Meanwhile some studies have shown that PD-1 as neoadjuvant therapy showed promising anti-tumor activity with acceptable tolerance for locally advanced ESCC. Previous studies have shown genomic amplification of 11q13 region may serve as a negative predictive marker for ESCC patients receiving anti-PD-1 based immunotherapy. However, related molecular characterization study of amplification of 11q13 region in patients with operable ESCC is rare reported. Methods: The study recruited pts with operable ESCC whose tissues were send to perform target-capture deep sequencing with the pan-cancer panel and immunohistochemistry of PD-L1 with 22C3 assay. Pair-wise comparison of TMB and PD-L1 was analyzed in pts with 11q13 amplification and pts without 11q13 amplification. Results: 58 operable ESCC pts (cT1-T3N0) were enrolled, median age at diagnosis was 63 years(yrs) (45-73). Copy number analysis identified 30 out of 58 (52%) patients with amplifications of four genes located in chromosome 11q13 region, including CCND1(Cyclin D1) and fibroblast growth factor family members ( FGF3/4/19). Among the 11q13 amplification cohort, four genes amplified together were occurred in 27(90%) pts, 1(3%) patient had amplification of three genes ( CCND1 and FGF3/4), 2 (7%) pts had amplification of one gene that are FGF3 and CCND1 respectively. The prevalence rate of 11q13 amplification was not significantly different between older age (≥ 63 yrs) and young age ( < 63 yrs). Among 58 pts with TMB evaluated, median TMB was 5.76 muts/Mb (range: 0 - 20.16 muts/Mb). The prevalence of TMB-H and microsatellite instability was 12% (7/58) and 0% (0/58). TMB and expression of PD-L1 showed no significantly difference between 11q13 amplification cohort and 11q13 wild cohort. The most frequently mutated genes were TP53 (96.7%, 29/30 pts), NOTCH1 (33.3%, 10/30 pts), CDKN2A (23.3%, 7/30 pts) and MLL2 (20%, 6/30 pts) in 11q13 amplification cohort, while TP53 (89.3%, 25/28), NOTCH1 (39.3%,11/28), MLL2 (28.6%, 8/28), FAT1 (25%,7/28) were the most frequently mutated genes in 11q13 wild cohort. Conclusions: Amplification of 11q13 region was a high prevalence event in operable ESCC and there was show no age bias. Molecular characterization of amplification of 11q13 region in patients receiving PD-1 as neoadjuvant therapy before surgery may be meaningful.
Genomic and molecular characterization of esophageal squamous cell carcinoma
