Virtual Library

Start Your Search

Xiaohua Hu



Author of

  • +

    EP1.12 - Small Cell Lung Cancer/NET (ID 202)

    • Event: WCLC 2019
    • Type: E-Poster Viewing in the Exhibit Hall
    • Track: Small Cell Lung Cancer/NET
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 08:00 - 18:00, Exhibit Hall
    • +

      EP1.12-10 - Molecular Characterization of NSCLC-Like and SCLC-Like Subsets in Chinese Pulmonary Large-Cell Neuroendocrine Carcinoma (LCNEC) (Now Available) (ID 1341)

      08:00 - 18:00  |  Author(s): Xiaohua Hu

      • Abstract
      • Slides

      Background

      LCNEC is an aggressive, biologically heterogenous carcinoma which can be molecularly characterized as SCLC-like and NSCLC-like. Accurate distinction of molecular subset is of major clinical relevance since it may guide treatment choices in LCNEC. Here we determined the genomic characteristics of the two LCNEC subsets in a Chinese cohort to clarify their correlations with traditional lung cancer histologies.

      Method

      FFPE samples from 31 LCNECs were sequenced using a 520-cancer-related gene panel, with an average sequencing depth of 1385X. Comparative mutational analysis was conducted between NSCLC-like LCNECs from our cohort and adenocarcinomas from TCGA dataset

      Result

      Despite similar clinical features in terms of stage and age at diagnosis, NSCLC-like (42%, 13/31) and SCLC-like (32%, 10/31) subsets from LCNEC displayed distinct molecular characteristics. NSCLC-like subset harbored significant higher mutation frequencies of STK11, KEAP1 and FAT3 (53.8%, 38.5% and 38.5%, p=.007, .046 and .046), while SCLC-like subset was characterized by highly mutated RB1 (100%, p<.001) and PTEN (50%, p=.007). Compared with TCGA adenocarcinomas, NSCLC-like LCNEC displayed more frequent mutations in TP53, STK11, APC, KMT2D and SMARCA4 (76.9%, 53.8%, 30.8%, 30.8% and 23.1%; p=.043, .004, .045, .005 and .049). In addition, potential targetable alterations were present in 46.2% (6/13) pts of NSCLC-like subset. For those advanced stage pts, 2/5 NSCLC-like and 5/5 SCLC-like pts received relevant chemotherapy according to their molecular characteristics. The clinical outcomes of these pts are still under follow-up.

      Conclusion

      This study demonstrates the distinct molecular features between NSCLC-like and SCLC-like subsets, and highlights the predominant genomic similarity and separate entities between NSCLC-like LCNEC with adenocarcinoma. Given the evidence that genomic profiling may aid in informing treatment decisions for pts with LCNEC, our study indicates that, based on accurate molecular typing, 46.2% NSCLC-like pts may benefit from potential targeted therapy and the rest of them may be more suitable to receive NSCLC-chemotherapy

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    OA03 - Systemic Therapies for SCLC: Novel Targets and Patients' Selection (ID 121)

    • Event: WCLC 2019
    • Type: Oral Session
    • Track: Small Cell Lung Cancer/NET
    • Presentations: 1
    • Now Available
    • +

      OA03.05 - Characterization of Genomic Alterations in Chinese LCNEC and SCLC via Comprehensive Genomic Profiling (Now Available) (ID 1486)

      13:30 - 15:00  |  Author(s): Xiaohua Hu

      • Abstract
      • Presentation
      • Slides

      Background

      LCNEC and SCLC are aggressive neuroendocrine carcinomas with overlap in clinical, histopathologic, morphologic and genomic features. Differential molecular features between the two subtypes have not been well elucidated, contributing the uncertainty for optimal clinical strategy for each subtype. Here we interrogated the genomic characteristics in LCNEC as compared to SCLC along with their histologically related subtypes: carcinoids and atypical carcinoids via comprehensive genomic profiling.

      Method

      FFPE samples from 31 LCNECs, 35 SCLCs, 14 carcinoids and 22 atypical carcinoids were sequenced in a CLIA-certified sequencing laboratory using 520-cancer-related gene panel, with an average sequencing depth of 1385X.

      Result

      Comparative mutational analysis revealed that both LCNEC and SCLC sub-cohorts displayed higher rate of TP53 alterations than that of carcinoid (p<0.001, p<0.001). SCLC patients harbored more RB1 and PIK3CA mutations than LCNECs (p<0.001, p=0.014) and carcinoids (p<0.001, p=0.018). In addition, mutation frequencies of LRP1B, FAT1, PRKDC, PIK3CA, NOTCH1, SPTA1 and EPHA3 in SCLC were significantly higher than that in carcinoid. Mutations in TP53 and RB1 occurred concurrently in 83% (29/35) SCLC patients, whereas in only 32.3% (10/31) LCNECs.(Fig.1) We further investigated the distribution of mutations across KEGG pathways and found that mutation frequencies in both HIF-1 and Notch signaling pathways were lower in LCNEC than SCLC (p=0.032, p=0.025). Copy number variation (CNV) analysis revealed that LCNEC and SCLC had comparable CNVs which were significantly higher than carcinoid (p<0.001, p<0.001) and atypical carcinoid (p=0.010, p=0.028). TMB analysis also revealed a comparable TMB status of LCNEC (12.7/Mb) and SCLC (11.9/Mb), and relatively lower TMB in both carcinoid (2.4/Mb, p<0.001, p<0.001) and atypical carcinoid (5.6/Mb, p=0.003, p=0.009) than LCNEC and SCLC.

      wclc lcnec figure 1.jpg

      Conclusion

      We demonstrated the differential genomic characteristics in the four subtypes of neuroendocrine carcinomas. Compared with SCLC, LCNEC has lower mutation frequencies in RB1, PIK3CA, as well as HIF-1 and Notch signaling pathways. In addition, LCNEC and SCLC had comparable CNV and TMB status, which significantly higher than that of carcinoids and atypical carcinoid.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    P1.14 - Targeted Therapy (ID 182)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Targeted Therapy
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
    • +

      P1.14-11 - A Prospective Multicenter Study of Target-Capture Deep Sequencing in Paired Tissue and ctDNA to Guide EGFR-Mutated Lung Cancer Treatment (Now Available) (ID 1542)

      09:45 - 18:00  |  Author(s): Xiaohua Hu

      • Abstract
      • Slides

      Background

      TKIs have significantly improved the survival of NSCLC pts carrying sensitive mutations. However, heterozygous responses were observed. We conducted a prospective multicenter clinical trial to explore factors associated with the efficacy of EGFR-TKI, and assess the mutation and TMB concordance between plasma and tissue NGS.

      Method

      Paired tumor and plasma samples were obtained from treatment naïve advanced NSCLC pts whenever applicable. DNA was sequenced by target-capture deep sequencing of 1021 tumor-related genes (pan-cancer panel). PFS was estimated using Kaplan-Meier method and compared using log-rank test. Tissue TMB (tTMB) and plasma TMB (bTMB) analysis interrogated SNVs/Indels with VAF ≥3 % and ≥0.5 %, respectively. TMB-H pts were identified with ≥9 muts/Mb.

      Result

      From Feb. 2017 to Jan. 2019, 262 advanced NSCLC pts were enrolled from 12 centers. In 224 pts with paired tumor and plasma samples, 144 had EGFR sensitive mutations in tumor samples (L858R, 46%; Ex19Indel, 42%), of whom, 106 (74%) had the identical mutations detected in plasma. The detection rate of tissue EGFR mutations in paired plasma was significantly higher in pts with extrathoracic metastasis (81% vs. 61%, p = 0.03). In 38 pts lacking paired samples, 20 pts had EGFR sensitive mutations detected. Thus, 164 pts were identified as EGFR positive by either plasma or tissue NGS. One hundred of them were treated EGFR TKIs (ORR: 70%, mPFS: 20 mo). The ORR was affected by EGFR subtypes (Ex19Indel vs. L858R: 72% vs. 45%, p = 0.02), concomitant CNV/fusion (with vs. without: 11% vs. 68%, p = 0.002) and CDKN2A mutations (with vs. without: 0% vs. 66%, p = 0.007). Mutations in p53 pathway (p = 0.02), CDK12/13 (p = 0.0002), concomitant CNV/fusion (p = 0.003), and high number of alterations (≥ 5) (p = 0.003) significantly shortened mPFS. tTMB was correlated with bTMB (rPearson = 0.9, p < 0.0001), with a concordance rate of 90% for TMB-H and TMB-L classification. Interestingly, 9.8% of the EGFR positive pts were bTMB-H, and mPFS was shorter in bTMB-H pts (6 mo, 95% CI: 5 - NR) than in bTMB-L pts (NR, 95%: 13 - NR) (p = 0.2).

      Conclusion

      Deep sequencing with the pan-cancer panel effectively detected mutations and evaluated TMB in both tissue and plasma with a high consistence. Moreover, the presence of structure variation, high tumor heterogeneity and concomitant mutations in genes such as CDKN2A were associated with worse prognosis. Further studies of predictive factors are ongoing (NCT03059641).

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.