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Chao Zhang
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JCSE01 - Joint IASLC-CSCO-CAALC Session (ID 63)
- Event: WCLC 2019
- Type: Joint IASLC-CSCO-CAALC Session
- Track:
- Presentations: 1
- Moderators:Chunxue Bai, Tony Mok, Yi-Long Wu, Qing Zhou, Nan Wu
- Coordinates: 9/07/2019, 07:00 - 11:15, Toronto (1985)
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JCSE01.16 - Metastatic Lymph Nodes as High Immunogenicity Media for Perioperative Immunotherapy in Locally Advanced NSCLC (ID 3430)
07:00 - 11:15 | Presenting Author(s): Chao Zhang
- Abstract
Abstract
Background
Perioperative chemotherapy showed limited survival benefit and increased toxicities while neoadjuvant immunotherapy achieved great success in early phase trials. Both inter/intra-tumoral heterogeneity (ITH) between primary lesion and metastatic lymph nodes (mLNs), and rationale of superior efficacy for immunotherapy remained poorly explored in locally advanced non-small cell lung cancer (NSCLC).
Methods
We retrospectively collected 6 locally advanced lung adenocarcinoma (LUAD) patients. 15 tissue samples were performed multi-region whole exosome sequencing and TCR repertoire analysis as well as 18 matched metastatic lymph nodes (mLNs).
Results
290 somatic mutations in average were identified in primary LUAD (PL) and 441.6 for mLNs. Tumor mutation burden as well as tumor neoantigen burden was significant higher in mLNs than in primary LUAD (median value, 6.6mut/Mb vs. 3.4mut/Mb, P=0.0376; 229.5 neo counts vs. 165 neo counts, P=0.0287). Increased transversion ratio was found in mLNs compared to primary lesions. The genomic concordance between primary lesions and mLNs was 58.4%±12.5% and 33.3% for EGFR-mutation. 87 copy number variants were detected in 14 samples with 3q, 8q and X chromosome as frequently mutated cytobands. Small cell lung cancer functional pathway was enriched in mLNs exclusively. Both expression of PD-L1 and CD8 revealed high level (median value 20% and 40%) and consistence (5/6, 83.3%) between primary and metastatsis lesions. TCR clonality was 17.2% and 9.1% for primary and metastasis lesions, respectively with higher T cell diversity and intra-tumoral heterogeneity of TCR found in mLNs.
Conclusion
Extensive genomic and TCR ITH was found between primary LUAD and mLNs which may lead to mixed response to perioperative treatment. mLNs may serve as a better immunogenicity media for perioperative immunotherapy suggesting a potential adjuvant modality of immunotherapy performing lymph nodes sampling during surgery. Results of an initiated single cell sequencing program including paired samples were pending to further provide insights of diverse immune-microenvironment.
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P2.03 - Biology (ID 162)
- Event: WCLC 2019
- Type: Poster Viewing in the Exhibit Hall
- Track: Biology
- Presentations: 1
- Moderators:
- Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
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P2.03-32 - Metastatic Lymph Nodes as High Immunogenicity Media for Perioperative Immunotherapy in Locally Advanced NSCLC (ID 289)
10:15 - 18:15 | Presenting Author(s): Chao Zhang
- Abstract
Background
Perioperative chemotherapy showed limited survival benefit and increased toxicities while neoadjuvant immunotherapy achieved great success in early phase trials. Both inter/intra-tumoral heterogeneity (ITH) between primary lesion and metastatic lymph nodes (mLNs), and rationale of superior efficacy for immunotherapy remained poorly explored in locally advanced non-small cell lung cancer (NSCLC).
Method
We retrospectively collected 6 locally advanced lung adenocarcinoma (LUAD) patients. 15 tissue samples were performed multi-region whole exosome sequencing and TCR repertoire analysis as well as 18 matched metastatic lymph nodes (mLNs).
Result
290 somatic mutations in average were identified in primary LUAD (PL) and 441.6 for mLNs. Tumor mutation burden as well as tumor neoantigen burden was significant higher in mLNs than in primary LUAD (median value, 6.6mut/Mb vs. 3.4mut/Mb, P=0.0376; 229.5 neo counts vs. 165 neo counts, P=0.0287). Increased transversion ratio was found in mLNs compared to primary lesions. The genomic concordance between primary lesions and mLNs was 58.4%±12.5% and 33.3% for EGFR-mutation. 87 copy number variants were detected in 14 samples with 3q, 8q and X chromosome as frequently mutated cytobands. Small cell lung cancer functional pathway was enriched in mLNs exclusively. Both expression of PD-L1 and CD8 revealed high level (median value 20% and 40%) and consistence (5/6, 83.3%) between primary and metastatsis lesions. TCR clonality was 17.2% and 9.1% for primary and metastasis lesions, respectively with higher T cell diversity and intra-tumoral heterogeneity of TCR found in mLNs.
Conclusion
Extensive genomic and TCR ITH was found between primary LUAD and mLNs which may lead to mixed response to perioperative treatment. mLNs may serve as a better immunogenicity media for perioperative immunotherapy suggesting a potential adjuvant modality of immunotherapy performing lymph nodes sampling during surgery. Results of an initiated single cell sequencing program including paired samples were pending to further provide insights of diverse immune-microenvironment.
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P2.17 - Treatment of Early Stage/Localized Disease (ID 189)
- Event: WCLC 2019
- Type: Poster Viewing in the Exhibit Hall
- Track: Treatment of Early Stage/Localized Disease
- Presentations: 1
- Moderators:
- Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
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P2.17-16 - Genomic Heterogeneity and Evolutionary Trajectory in Multifocal Synchronous Lung Cancer (ID 2082)
10:15 - 18:15 | Author(s): Chao Zhang
- Abstract
Background
Multifocal synchronous lung cancer (MSLC) presented as coexistence of multiple tumor lesions that share an identical germline genetic background and environmental exposure in individual patients. Along with the improved resolution of cross-sectional imaging, multiple types of ground glass opacities (GGOs) have been detected in increasing frequency as well as solid nodules even in an unique patient. However the molecular origins and relationships among the synchronous lesions remain unclear.
Method
10 treatment-naive MSLC patients were retrospectively collected while 25 tissue samples were performed whole exosome sequencing. In addition, we constructed phylogenetic trees to estimate the ancestral relationships of individual foci.
Result
79 somatic mutations in average were identified in MSLC tissues. The most significant mutated gene EGFR has been detected in 10 samples from 7 patients in our cohort. Tumor mutation burden as was significantly higher in IAC lesions than AIS/MIA ones. The mutation spectra of single-nucleotide variations (SNVs) were fairly consistent across the same histologic type even from different patients. Compared to AIS/MIA, IAC samples displayed a preponderance of A>T/T>A transition (Ti) while less frequency of A>C/T>G transversion (Tv). However few share mutations were located by pair of lesions in individual patients. Distinct genomic profiles suggested all were primary tumours. WNT pathway was enriched in AIS/MIA lesions exclusively while IAC appeared TGFβ/TP53 pathway mutation associated with cell proliferation and apoptosis.
Conclusion
Even in the same individual patient different lung cancer lesions may be driven by distinct genomic profiles so that each presented its own evolutionary trajectory. A deeper understanding of tumorigenesis is still in need to improve the diagnosis and treatment of MSLC.
