The Association Between Ki-67 Proliferation Index and Disease Progression in Gastro Intestinal Stromal Tumors: A Retrospective Study

Introduction: Approximately 40% to 50% of high risk Gastro intestinal stromal 
tumors progress even with complete surgical resection. Therefore, 
prognostication of patients is essential to determine the risk of recurrence and 
influence management decisions. Many risk stratification systems have 
developed. Tumor size, site and mitotic count are the major clinicopathologic 
risk factors together with tumor rupture. The nuclear proliferating protein ki-67 
has demonstrated its prognostic significance in the outcome of various 
malignancies but in gastro intestinal stromal tumors, the relationship between its 
overexpression and the risk of disease recurrence remains poorly defined. 
Aim of the work: To investigate whether Ki-67 labelling index can be 
considered an independent predictor for disease progression or not.
Patients and methods: This is a retrospective study that enrolled patients with 
localized stage of gastrointestinal stromal tumors treated by surgical excision 
and adjuvant Imatinib mesylate in the Governorate of Sohag between January
2012 and January 2022.
Results: A total of 74 Egyptian patients with localized gastrointestinal stromal 
tumors treated with excision and adjuvant Imatinib mesylate have been 
retrospectively analyzed. The median age was 53 year and the median follow up 
period was at 40 months. During follow up, 27% has developed progressions 
both local and distant and 12% has died. Among the studied risk factors, only 
the extra gastric location and Ki-67% labelling index >7% were associated with 
more disease recurrences in univariate analysis. A labelling index ≤7% was 
associated with better local and distant control in the studied subgroups but with 
no effect on overall survival. 
Conclusion: Ki-67% labelling index >7% is an important prognostic indicator 
of high risk of disease progression after surgical excision of localized GIST and 
more larger studies are warranted.