Role of surgery in locally progressive gastrointestinal stromal tumors after imatinib therapy: A prospective multicenter real-world study.

Abstract

121 Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal tract. The impact of surgical resection on progression-free survival (PFS) in patients with locally progressive GIST after imatinib therapy remains incompletely defined. This study aimed to explore the role of surgery in improving outcomes in this patient population. Methods: This prospective study, initiated in January 2018, included 110 patients from five tertiary centers in China: Zhongshan Hospital, Fudan University (n = 40); Fudan University Shanghai Cancer Center (n = 35); First Affiliated Hospital of Naval Medical University (n = 24); Renji Hospital, Shanghai Jiao Tong University (n = 9); Ruijin Hospital, Shanghai Jiao Tong University (n = 2). Patients were divided into Group A (n = 49, surgical resection) and Group B (n = 61, imatinib dose escalation or subsequent-line agents). Clinical and pathological features were recorded, including age, sex, primary tumor site, tumor size, mitotic index, and imatinib treatment duration. Continuous variables were summarized as median (range). PFS was estimated using the Kaplan-Meier method and compared by log-rank test. Results: Among the 110 patients, 75 (68.2%) were male and 35 (31.8%) were female, with a median age at diagnosis of 61 years (range, 19–84). Tumor characteristics included a median size of 55 mm (range, 25–144 mm) and a median mitotic count of 3/50 HPF (range, 1–7). The primary tumor sites were stomach (47%), intestine (35%), rectum (10%), and others (8%). All patients had received prior imatinib therapy and experienced local disease progression, with a median treatment duration of 36 months (range, 2–144). Among them, 49 patients underwent surgical resection (Group A), while 61 patients received imatinib dose escalation or subsequent-line agents (Group B). At 12 months, the estimated 1-year progression-free survival (PFS) was 94% in Group A versus 82% in Group B, showing a statistically significant difference (log-rank P = 0.04). Conclusions: Surgical resection improves progression-free survival in patients with locally progressive GISTs after imatinib therapy, supporting the role of surgery in selected patients even in the era of targeted therapy. Clinical trial information: ChiCTR2000029913 .