KEY TAKEAWAYS
- An observational study aimed to describe the long-term outcomes of SDH-deficient GIST pts.
- Data from pts enrolled in an NIH study were evaluated, including tumor sequencing and germline testing.
- The study found that long-term follow-up of SDH-deficient GIST pts would help understand how this rare disease progresses and develops over time for better treatment and patient monitoring.
Gastrointestinal stromal tumors (GISTs) are a type of cancer that can occur anywhere in the digestive system. Most GISTs are caused by mutations in the KIT or PDGFRA genes, but about 10% are caused by mutations in the SDH genes. There are no effective systemic therapies for SDH-deficient GISTs, but they are typically slow-growing tumors.
Researchers aimed to describe the long-term outcomes of these patients (pts).
Data from SDH-Deficient GIST pts at NIH were examined. Medical records and imaging were reviewed, and SDH gene sequencing was used to characterize tumors. Consent was obtained for germline SDH gene analysis for pts and families.
Clinical information and specimens were collected from 77 GIST pts (median age at diagnosis 21.5, [range 7-57] years; 72.7% (56) female, 21.3% (21) male). Molecular subtypes classified them as 33.8% SDHC epimutation, 28.6% SDHA, 22.1% SDHB, 14.3% SDHC, and 1.3% SDHD.
The median age at presentation of SDHC epimutation was younger (14.5 years, range: 8-56) when compared to SDHA (27.5 years, range: 7-55), SDHB (22 years, range: 8-54), SDHC (18 years, range: 10-57), and SDHD (39 years, N = 1). Most commonly, pts had at least one surgery (55.8%), while a lower proportion had four or more (7.8%). Primary tumors occurred in the stomach, with 26% having metastases at presentation, the most common location being the liver (10.4%).
Overall, 64.9% of patients were treated with imatinib, 39% were treated with sunitinib, and 15.6% received other systemic therapies. Within the cohort, 13% of pts had paragangliomas, 6.5% had chondromas, and only 9.1% had a family history of GIST.
The study found that long-term follow-up of SDH-deficient GIST pts would help understand how this rare disease progresses and develops over time for better treatment and patient monitoring.
Source: https://ascopubs.org/doi/abs/10.1200/JCO.2023.41.16_suppl.11542
Clinical Trial: https://clinicaltrials.gov/study/NCT03739827
Urania Dagalakis, Shadin Ghabra, Erika Kaschak, Maran Ilanchezhian, Jaydira Del Rivero, Markku Miettinen, Audra A Sutterwhite, B. J. Thomas, Donna Bernstein, Margarita Raygada, Crystal Flowers, Keith Killian, Paul S. Meltzer, Karlyne Reilly, Mary Frances Wedekind, Brigitte C. Widemann, Hari Sankaran, Andrew M. Blakely, and John Glod. DOI: 10.1200/JCO.2023.41.16_suppl.11542 Journal of Clinical Oncology 41, no. 16_suppl (June 01, 2023) 11542-11542.
