Precision and personalized multidisciplinary management of a giant gastrointestinal stromal tumor (GIST) harboring KIT exon 11 and 13 mutations: a case report of long-term survival

Background: Giant gastrointestinal stromal tumors (GISTs) carry a high risk of recurrence and poor prognosis, making precision and personalized multidisciplinary management essential. Case Description: A 64-year-old female presented with a giant gastric GIST (a maximum diameter of 144.6 mm) confirmed by biopsy (CD117+, DOG-1+). After 12 months of neoadjuvant imatinib, the tumor shrank significantly, enabling R0 resection. Following 20 months of adjuvant imatinib, hepatic oligometastasis occurred and was managed with surgery and second-line sunitinib, which achieved disease control but caused grade 2 hypertension. After sunitinib resistance, genetic testing indicated mutations in KIT (KIT proto-oncogene, receptor tyrosine kinase) exons 11 (p. V559D) and 13 (p. V654A). Considering both efficacy and safety, and taking into account the patient’s preference, ripretinib was initiated, providing 18 months of stable disease (SD); subsequent ripretinib intrapatient dose escalation (IPDE) extended SD by an additional 9 months. Later, regorafenib achieved 6 months of SD. Across tyrosine kinase inhibitor (TKI) treatment, four surgeries were performed for oligometastatic lesions. Overall survival (OS) was 105 months (~8.8 years) from initial diagnosis. Conclusions: This case highlights that precision and personalized multidisciplinary strategies integrating TKIs and surgery can achieve long-term disease control in advanced GIST. Front-line treatment with ripretinib (including standard dose and IPDE) may provide survival benefits. Multidisciplinary collaboration remains critical for optimizing outcomes in complex cases.