Abstract 2596
Background
Succinate dehydrogenase (SDH) is a highly conserved component of energy production and metabolism. Genetic or epigenetic inactivation of SDH (dSDH) creates a state of intracellular pseudohypoxia that is uniquely oncogenic for subtypes of GIST, renal cell carcinoma (RCC), paraganglioma/pheochromocytoma (PGL/Pheo), and pituitary adenoma/carcinoma (PAC). dSHD stems from homozygous loss of one of four subunit encoding genes SDHA, SDHB, SDHC, or SDHD (aka, SDHx). dSDH is not targetable, and preclinical models are poorly viable. In the current study we analyze comprehensive genomic profiles (CGP) from a dSDH pan-tumor cohort for potential therapy-enabling non-SDHx genomic alterations and biomarkers (GA).
Methods
231,706 clinical grade CGP were searched for dSDH GIST, RCC, PGL/Pheo, and PAC. GA were determined on 1.1 Mb genome sequence encompassing up to 324 cancer genes. dSDH was further established by histopathology review and analysis of SDHx homozygous loss. Germline and zygosity status of SDHx variants were performed by SGZ algorithm. Non-SDHx GA were assessed for therapeutic actionability.
Results
82 SDH-deficient neoplasms were analyzed (Table). 0 of 38 GIST had highly actionable GA. In one case a subclonal KIT variant was identified in a recurrence of an SDHA-mutant GIST treated with Imatinib for several years. No clonal canonical driver kinase mutations were identified in KIT, PDGFRA, NF1, BRAF, FGFR1 or NTRK1-3. 0 of 36 dSDH PGL/Pheo and 0 of 1 PAC had potential therapeutic options. 2 of 7 dSDH RCC reported potential treatment options for oncogenic variants in EGFR and CDK4. No dSDH tumors had high TMB, microsatellite instability, or LOH score indicative of homologous recombination defect (HRD). Overall, 2 of 82 tumors (2.4%) harbored highly actionable GA.Table:
2039P
82 SDH-deficient tumors | ||||
---|---|---|---|---|
GIST (n = 38) | PGL/Pheo (n = 36) | RCC (n = 7) | PAC (n = 1) | |
Age (mean) | 33 | 40 | 49 | 44 |
Sex ratio (M/F) | 16/21 | 24/12 | 4/3 | 0/1 |
SDHA | 11 | 12 | 3 | 1 |
SDHB | 7 | 21 | 3 | 0 |
SDHC | 4 | 1 | 1 | 0 |
SDHD | 2 | 2 | 0 | 0 |
SDHx-WT | 14 | 0 | 0 | 0 |
%SDHx germline | 69 | 64 | 100 | 50 |
GA/tumor (pathogenic non-SDHx) | 0.58 | 0.89 | 2.29 | 0 |
MSI | 0 | 0 | 0 | 0 |
TMB (mut/Mb, mean) | 1.86 | 2.4 | 3 | 0.9 |
HRD (LOHscore >16%) | 0 | 0 | 0 | 0 |
Conclusions
This study identifies SDH deficiency as a lone driver of malignancy and without associated actionable GA in > 97% of cases, and underscores the need for novel therapeutic approaches targeting SDH deficiency itself.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Foundation Medicine.
Funding
Foundation Medicine.
Disclosure
J.K. Killian: Full / Part-time employment: Foundation Medicine. D.C. Pavlick: Full / Part-time employment: Foundation Medicine. E.S. Sokol: Full / Part-time employment: Foundation Medicine. M. Montesion: Full / Part-time employment: Foundation Medicine. D.X. Jin: Full / Part-time employment: Foundation Medicine. B. Kaplan: Full / Part-time employment: Foundation Medicine. D. Lin: Full / Part-time employment: Foundation Medicine. J. Vergilio: Full / Part-time employment: Foundation Medicine. J.A. Elvin: Full / Part-time employment: Foundation Medicine. N. Ngo: Full / Part-time employment: Foundation Medicine. E. Severson: Full / Part-time employment: Foundation Medicine. S. Ramkissoon: Full / Part-time employment: Foundation Medicine. D. Duncan: Full / Part-time employment: Foundation Medicine. C. Edgerly: Full / Part-time employment: Foundation Medicine. A. Hemmerich: Full / Part-time employment: Foundation Medicine. G.M. Frampton: Full / Part-time employment: Foundation Medicine. V.A. Miller: Full / Part-time employment: Foundation Medicine. S.M. Ali: Full / Part-time employment: Foundation Medicine. J.S. Ross: Full / Part-time employment: Foundation Medicine. All other authors have declared no conflicts of interest.
Resources from the same session
2045 - The analysis of treatment sequences and clinical outcomes of thymic carcinoma
Presenter: Arakaki Motoko
Session: Poster Display session 1
Resources:
Abstract
4785 - Transcriptomic Difference of Thymoma and Thymic Carcinoma
Presenter: Naixin Liang
Session: Poster Display session 1
Resources:
Abstract
2864 - A Phase II Trial of Preoperative Chemoradiotherapy and Pembrolizumab for Locally Advanced Esophageal Squamous Cell Carcinoma (ESCC)
Presenter: Seoyoung Lee
Session: Poster Display session 1
Resources:
Abstract
5015 - The study of tumor associated exosomes in crosstalk between esophageal carcinoma and lymphatic endothelial cells
Presenter: Weimin Mao
Session: Poster Display session 1
Resources:
Abstract
1339 - Up-regulation of IBSP expression predicts poor prognosis of Esophageal Squamous Cell Carcinoma patients
Presenter: Mingyue Wang
Session: Poster Display session 1
Resources:
Abstract
4083 - PD-L1 expression in primary tumour vs metastatic samples in the Phase 3 MYSTIC study in first-line metastatic (m) NSCLC
Presenter: Niels Reinmuth
Session: Poster Display session 1
Resources:
Abstract
5113 - Assessing the impact of subsequent checkpoint inhibitor (CPI) treatment on overall survival: post hoc analyses from the phase 3 JAVELIN Lung 200 study of avelumab vs docetaxel in platinum-treated locally advanced/metastatic non-small cell lung cancer (NSCLC)
Presenter: Fabrice Barlesi
Session: Poster Display session 1
Resources:
Abstract
4256 - Long-term avelumab treatment in patients with advanced non-small cell lung cancer (NSCLC): post hoc analyses from JAVELIN Solid Tumor
Presenter: Borys Hrinczenko
Session: Poster Display session 1
Resources:
Abstract
4305 - Effectiveness and safety of nivolumab in the treatment of lung cancer patients in France: Updated survival and subgroup analysis from the real-world EVIDENS study
Presenter: Fabrice Barlesi
Session: Poster Display session 1
Resources:
Abstract
5128 - IO-Synthesise NSCLC: A pooled analysis of real-world survival outcomes for non-small cell lung cancer patients treated with nivolumab in France and Germany
Presenter: Adrien Dixmier
Session: Poster Display session 1
Resources:
Abstract