Molecular characterization of amplification of 11q13 region in patients with operable esophageal squamous cell carcinoma.

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.

The landscape of chromosome 11q13 amplification in Chinese solid tumor patients and hyperprogressive disease (HPD) clinical example.

e15222 Background: Multiple biomarkers are thought to be effective guides in selecting immune checkpoint inhibitors, such as Tumor mutational burden (TMB), PD-L1 and MSI/dMMR. Immunotherapy may be miraculous effective in some patients but many other patients experienced poor prognosis and even tumor overgrowth after immunotherapy in real practice. Previous studies have reported that 11q13 (CCND1, FGF3, FGF4, and FGF19) amplifications were associated with HPD. However, the characterization of chromosome 11q13 amplification in Chinese solid tumor patients are not clear. Methods: A total of 10167 Chinese solid tumor patients’ FFPE and matching blood samples sequenced by next-generation sequencing (NGS) targeting 450 cancer genes were included in this study. Genomic alterations including single nucleotide variants (SNV), insertions and deletions, copy number variations and fusions were assessed. The testing was carried out by a College of American Pathologists (CAP) accredited and Clinical Laboratory Improvement Amendments (CLIA) certified laboratory. Results: Chromosome 11q13 amplifications were identified in 679 (6.7%) Chinese solid tumor patients. The top six tumor types with 11q13 amplification were esophageal carcinoma 43.8%, melanoma 17%, urothelial carcinoma 16%, breast carcinoma 13.4%, head and neck carcinoma 13.1% and hepatocellular carcinoma 9.4%. In 2257 patients with TMB-H (10muts/Mb) / PD-L1 expression / MSI samples, chromosome 11q13 copy number gain were identified in 184 (8.2%) patients. Chromosome 11q13 amplification and MSI were independent events and didn't occur simultaneously. In TMB-H patients, the detection rate of 11q13 amplification was 8.5%, while in PD-L1 positive patients, the amplification rate of 11q13 was 7.4%. In patients with TMB-H and PD-L1 positive, the detection rate of 11q13 amplification was 9.4%. In our clinical practice, we saw example of HPD exist in a lung squamous cell carcinoma patient who was treated with multiple lines of therapy and then used the Nivolumab. The patient underwent genetic testing and was found to be chromosome 11q13 amplified. Conclusions: The proportion of 11q13 amplification was different in different types of solid tumor. Esophageal carcinoma, melanoma and urothelial carcinoma were top three types of solid tumors with 11q13 amplification. The 11q13 amplification did not coincide with MSI but it overlapped with PD-L1 expression or TMB-H. Together, these results may provide immunotherapy guidance in clinical practice.