245 Prognostic Factors for Recurrence and Overall Survival in Primary Gastrointestinal Stromal Tumors (GISTs) Undergoing Resection: A 12-Year Tertiary Centre Experience with Univariate, Multivariate, and Kaplan–Meier Analysis

Abstract Aim To identify risk factors for recurrence and survival in primary GIST resection. Method A retrospective analysis of 152 primary GIST resections performed at a tertiary centre between 2012 and 2024 was conducted. The final follow-up date was May 1, 2025. Univariate analyses identified associations between clinical-pathological variables and recurrence or survival. Variables with p<0.05 were included in multivariable logistic regression to identify independent predictors. Kaplan–Meier (KM) estimated recurrence-free survival (RFS) by risk classifications (Fletcher, NIH, Miettinen) and significant independent multivariate predictors. Overall survival (OS) KM analysis was performed for significant multivariate predictors only. Log-rank test compared survival. SPSS 24 was used with significance: p<0.05. Results Recurrence occurred in 12.5% of patients. Univariate predictors included age >50 (p=0.049), tumour size (p=0.038), non-gastric location (p=0.031), high mitotic rate (p=0.021), multivisceral resection(p=0.041), IHC markers (p=0.007), death during follow-up (p=0.002), and failure to reach five-year survival (p=0.021). On multivariate analysis, high mitotic rate was the only factor independently predictive of recurrence(p=0.006). KM analysis showed lower RFS in high mitotic index and non-gastric tumours. Risk models stratified recurrence effectively. Overall mortality was significantly associated with male gender (p=0.002), tumor size (p=0.024), non-gastric site (p=0.001), high mitotic index (p=0.040), R1/R2 resection (p=0.024), metastasis (p=0.002), and recurrence(p=0.049). On multivariate analysis, male gender(p=0.011) and recurrence (p=0.006) independently predicted mortality. KM analysis showed lower OS with high mitotic index, non-gastric tumours, and epithelioid histology. Conclusions Recurrence and survival in GIST are influenced by mitotic activity, tumour location, and surgical factors. Early risk identification supports individualised management approaches.