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
4242 - HIV, HBV and HCV screening practices in oncology: a cross-sectional interregional survey
Presenter: Isabelle Poizot-Martin
Session: Poster Display session 1
Resources:
Abstract
1267 - Genetic landscape of KEAP1 and NFE2L2 mutated cancers from the AACR GENIE database
Presenter: Mark Zaki
Session: Poster Display session 1
Resources:
Abstract
878 - β-arrestin1 is involved in the Ras-induced malignant transformation
Presenter: Takashi Shibano
Session: Poster Display session 1
Resources:
Abstract
4143 - Incidence of second cancer among PLWHIV: retrospective observational study of a series of 601 patients in the French CANCERVIH network
Presenter: Jean-Philippe Spano
Session: Poster Display session 1
Resources:
Abstract
5145 - A challenging task – Identifying carcinoma of unknown primary (CUP) patients according to ESMO guidelines: the CUPISCO trial experience
Presenter: Chantal Pauli
Session: Poster Display session 1
Resources:
Abstract
1737 - Incidence and Outcome of chronic lymphocytic leukemia with Deletion 17p: An Indian experience; challenges and opportunities
Presenter: Ajay Gogia
Session: Poster Display session 1
Resources:
Abstract
1499 - The potential of a novel antiangiogenic VEGFR1-D2 binding peptide in oncology therapeutics
Presenter: Afsaneh Sadre Momtaz
Session: Poster Display session 1
Resources:
Abstract
1775 - First-in-human phase I study of TAS-117, an allosteric AKT inhibitor, in patients with advanced solid tumors
Presenter: Mayu Yunokawa
Session: Poster Display session 1
Resources:
Abstract
4584 - First-in-human study of ABBV-621 in patients (pts) with previously treated sold tumors: Dose-optimization cohorts
Presenter: Emiliano Calvo
Session: Poster Display session 1
Resources:
Abstract
3620 - Safety, efficacy, PK and PD biomarker results of the first-in-human study of mutant isocitrate dehydrogenase 1 (mIDH1) inhibitor BAY 1436032 in patients (pts) with mIDH1 advanced solid tumours
Presenter: Wolfgang Wick
Session: Poster Display session 1
Resources:
Abstract