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
3336 - Survival outcome of non-small cell lung cancer (NSCLC) patients: Comparing results between the database of the Comprehensive Cancer Center Zürich (CCCZ) and the Epidemiological Cancer Registry Zurich and Zug (KKR)
Presenter: Rolf A. Stahel
Session: Poster Display session 1
Resources:
Abstract
2204 - NORA trial (GECP 15/02): Updated results of the Spanish Lung Cancer Group (SLCG) phase II trial of concurrent chemo-radiotherapy (CT-RT) with cisplatin (P) plus metronomic oral vinorelbine (mOV) for unresectable locally advanced non-small cell lung cancer (LA-NSCLC)
Presenter: María Guirado
Session: Poster Display session 1
Resources:
Abstract
1446 - A nomogram to predict outcomes of lung cancer patients after pneumonectomy based on 47 indicators set by principle component analysis
Presenter: Bo Cheng
Session: Poster Display session 1
Resources:
Abstract
1788 - Prognostic and predictive value of 18F-PET/CT on the response to treatment in locally advanced non-small cell lung cancer (NSCLC)
Presenter: Cristina Alfaro Autor
Session: Poster Display session 1
Resources:
Abstract
2299 - Comparison of three different chemotherapy regimens for concomitant chemoradiotherapy in locally advanced non small cell lung cancer
Presenter: Abdurrahman Işıkdoğan
Session: Poster Display session 1
Resources:
Abstract
4211 - Predicting the first failure pattern in patients with inoperable local advanced non-small cell lung cancer (LA-NSCLC) receiving definitive chemoradiotherapy: Establishment and internal validation of a nomogram based on the clinicopathological factors
Presenter: Xueru Zhu
Session: Poster Display session 1
Resources:
Abstract
1550 - Prognostic impact of neutrophil-to-lymphocyte ratio (NLR) pre and post chemoradiotherapy (CRT) in stage III non-small cell lung cancer (NSCLC)
Presenter: Vicente Palomar Abril
Session: Poster Display session 1
Resources:
Abstract
2345 - Meta-analysis evaluating neutropenia incidence with EGFR inhibitors and chemotherapy in patients with NSCLC
Presenter: Bernardo Rapoport
Session: Poster Display session 1
Resources:
Abstract
3747 - Effector CD4+ T-cell induction by thoracic radiotherapy for patients with NSCLC
Presenter: Yu Miura
Session: Poster Display session 1
Resources:
Abstract
3317 - Circulating tumor DNA (ctDNA) analysis in patients (pts) with non-small cell lung cancer (NSCLC) treated with telisotuzumab vedotin (teliso-v), an antibody-drug conjugate targeting c-Met
Presenter: Rebecca Heist
Session: Poster Display session 1
Resources:
Abstract