Background
To evaluate factors predicting surgical resection of SDH-deficient GIST and outcomes of adjuvant therapies. SDH-deficient GIST are very rare, comprising 5-7.5% of all GIST and most frequently occurring in the stomach or small bowel. Veterans who were exposed to burn pit toxins have an increased risk of developing these tumors. While most patients undergo surgery, there is limited information available regarding prognosis and survivability
Methods
The National Cancer Database was used to identify patients diagnosed with SDH-deficient GIST from 2004 to 2019 using histology code 8936 as assigned by the Commission on Cancer Accreditation program. Kaplan-Meier, ANOVA Chi-Square, and Logistic Regression tests were performed, and data were analyzed using SPSS version 29. Statistical significance was set at α = 0.05.
Results
721 patients with SDH-deficient GIST were queried, with 606 (84.05%) receiving surgical resection. Surgical patients experienced longer overall survival than non-surgical patients (116.3 months vs. 48.05 months, p< 0.001), with 248 (40.9%) patients undergoing a lobectomy and 29 (4.79%) patients undergoing a wedge/segmental resection. Patients who received wedge/segmental resection survived for 109.5 months while those who received a lobectomy survived for 108.6 months. Both surgeries showed a greater survival than other types of resections (p< 0.001). Of the initial sample, 42 (6.93%) patients received adjuvant chemotherapy, 3 (0.50%) patients received adjuvant radiation, and 3 (0.50%) patients received both. None of these adjuvants impacted overall survival. Stage I-II disease and well to moderately differentiated disease predicted an increased likelihood of receiving surgery (p< 0.001), while liver metastases predicted a decreased likelihood of receiving surgery (p< 0.001). Income status, race, insurance, facility type, and age were not significant predicting factors of receiving surgery.
Conclusions
Surgical resection of SDH-deficient GIST is associated with improved overall survival. Adjuvant therapies do not significantly improve survival over surgery alone. Patients with lower stage and grade of disease are more likely to receive surgery, while other social, economic, and demographic factors do not significantly affect the likelihood of receiving surgery. Surgical resection of SDH-deficient GIST is significantly associated with improved overall survival without the need for adjuvant therapies.
