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Poster Session (ID 8)
- Event: ACLC 2018
- Type: Poster Session
- Presentations: 2
- Coordinates: 11/07/2018, 00:00 - 00:00, Poster Hall
P028 - A Novel Method for Detecting Surface PD-L1 on Circulating Tumor Cells in Peripheral Blood of Patients with SCLC (ID 135)
00:00 - 00:00 | Author(s): H. Li
Previous studies have demonstrated that circulating tumor cell (CTC) might work as an alternative to biopsy tissues in the diagnoses of small cell lung cancer (SCLC). Programmed death ligand 1 (PD-L1) is one of the most commonly used biomarkers in immune targeted therapies. However, the expression of PD-L1 in CTC is still unknown. This study aimed to establish an approach to measure PD-L1 in peripheral CTCs from SCLC patients.
Control cells were screened by monoclonal culture and confirmed by immunohistochemistry (IHC) staining and flow cytometry. PD-L1 expression in CTCs and tumor tissue samples from SCLC patients was measured by CellSearch system while the usage of PD-L1 antibody was optimized.
The purity of PD-L1 positive H446 cells had been improved from 70% to 95% by clonal selection, and PD-L1 negative PC3 cells showed lower than 5% purity. In CellSearch system, positive control cells had 98% PD-L1 expression while negative control had less than 3% expression. In two SCLC patients with CTC positive expression, PD-L1 expression was found with 100% (1/1) and 40% (2/5) positive rate.
CellSearch system was used to establish a novel approach for measuring surface PD-L1 expression on CTC, and showed supporting evidences in SCLC patients, thus providing novel insights for automatic assay of PD-L1 in peripheral samples.
P107 - The Study of Relationship Between Tumor Burden (TMB) and Molecular Typing of Non-Small Cell Lung Cancer (NSCLC) (ID 127)
00:00 - 00:00 | Author(s): H. Li
Tumor mutation burden (TMB) is one of the strongest biomarker to stratify patients suitable for immunotherapy. However, the relationship between TMB and other typical genetic profile in lung adenocarcinoma is not clear. This study aimed to explore the genetic characteristics of non-small cell lung cancer (NSCLC) relationship between TMB and typical genetic profile in NSCLC patients.
Tumor tissue from 11 NSCLC patients in Jilin Cancer Hospital from July 2018 to August 2018 were tested by next generation sequencing (>500 target gene panel). 10 mutations/1 M basepairs as cut-off value, patients were divided into high tumor butden (TMB-High) and low tumor burden (TMB-Low). TMB relationship with lung cancer core genes (EGFR, ALK, ROS1, KRAS, BRAF, MET, RET and ERBB2), tumor suppressor genes, proto-oncogenes, and MSI was statistically analyzed.
Among the 11 NSCLC patients, 45% (5/11) of patients were TMB-low and 55% (6/11) of patients were TMB- high. 100% (11/11) of patients were microsatellite Stable (MSS) and there were no MSI patients. In TMB-low patients, there were 14 mutations in 9 tumor suppressor genes and 1 mutation in 1 proto-oncogene; 40% (2/5) of these patients had TP53 mutations; 60% (3/5) of these patients had 5 mutations in 4 lung cancer core genes (EGFR, MET, KRAS and ROS1). In TMB-high patients, there were 29 mutations in 17 tumor suppressor genes, 8 mutations in 4 proto-oncogenes; 100% (6/6) of these patients had TP53 mutations.; 83% (5/6) of these patients had 9 mutations in 4 lung cancer core genes.
Compared with TMB-high, TMB-low patients have less number of tumor suppressor genes, proto-oncogene mutations, TP53 mutations and lung cancer core gene mutations In addition, TMB may not be associated with MSI. This study could further understand the genetic characteristics of NSCLC and provide new theoretical basis for immunotherapy for NSCLC.