Case Report: Metastatic succinate dehydrogenase–deficient gastrointestinal stromal tumor treated with chemotherapy and immune checkpoint inhibitor

We report a young adult with a recurrent metastatic succinate dehydrogenase (SDH)–deficient gastrointestinal stromal tumor (GIST) achieving a pathological complete response with a chemoimmunotherapy regimen. The patient underwent a gastroscopy, which revealed a large-ulcerated tumor on the greater g...

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Bibliographic Details
Main Authors: Arthur Claessens, Jérôme Edouard Plaza, Jean-Yves Blay
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-03-01
Series:Frontiers in Oncology
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Online Access:https://www.frontiersin.org/articles/10.3389/fonc.2025.1549232/full
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Summary:We report a young adult with a recurrent metastatic succinate dehydrogenase (SDH)–deficient gastrointestinal stromal tumor (GIST) achieving a pathological complete response with a chemoimmunotherapy regimen. The patient underwent a gastroscopy, which revealed a large-ulcerated tumor on the greater gastric curvature. Histological analysis showed a poorly differentiated SDHB-deficient GIST with PDL1 expression at a 100% rate and a RET gene fusion. Rapid metastatic relapse after subtotal gastrectomy was resistant to imatinib. The patient received four cycles of cisplatin, etoposide, and pembrolizumab followed by pembrolizumab maintenance with a complete response. Late relapse 3 years later was treated with the same regimen and achieved complete pathological response. Two years later, an isolated focus was removed, showing the recurrent SDH-deficient GIST. Pembrolizumab is still in maintenance with no relapse to date. The role of chemoimmunotherapy as part of treatment in recurrent metastatic SDH-deficient, PDL1-positive GIST patients is worth further investigation.
ISSN:2234-943X