Retrospective analysis of clinicopathological characteristics and survival outcome of gastrointestinal stromal tumors: Real-world experience

Objectives: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Its true incidence, prevalence, and outcome have been less studied in the Indian subcontinent. We conducted the study to analyze the clinicopathological and survival outcomes of GIST patients to get a real-world scenario of a tertiary care hospital in India. Material and Methods: A retrospective review was conducted of all newly diagnosed GIST patients presenting from January 2015 to December 2024 to the radiotherapy department of a tertiary care hospital in Kolkata. Data on demographic, clinical, pathological, treatment, and follow-up details were retrieved from case records. Patients were categorized as operable localized, unresectable non-metastatic, or metastatic GIST. Operated cases were risk-stratified using the College of American Pathologists (CAP) criteria. Survival analysis was performed with DFS calculated for upfront operated patients and progression-free survival (PFS) for those patients who presented with unresectable non-metastatic disease and metastatic disease. Results: The cohort of 51 patients (mean age 50.7 years; 37 (72.5%) male, 14 (27.5%) female) had a median follow-up of 34 months. At presentation, 34 patients (67%) had operable localized disease, 8 patients (15%) had unresectable non-metastatic disease, and 9 patients (18%) had metastatic disease. The primary tumor originated in the small intestine in 21 patients (41%) and in the stomach in 19 patients (37%), with the remaining cases arising in the rectum, colon, or retroperitoneum. 5-Year DFS for localized operable cases was 89%. 3-Year PFS for unresectable non-metastatic GIST patients was 68%. Median PFS for metastatic cases was only 20 months, and 3-year PFS for metastatic cases was only 17%. Conclusion: Our study revealed a nearly equal distribution of GISTs between the stomach and small intestine, despite the stomach being the most common primary site reported in the global literature. The occurrence of localized and metastatic GIST aligns with global literature findings, though our patients presented at a younger age with a higher male predominance. Survival outcome is at par with the Western data. Late recurrences are common after completion of adjuvant Imatinib, which warrants longer follow-up.