The relationship between Ki-67 expression and imaging signs and pathological features in GISTs

Area of Science:

• Oncology
• Radiology
• Pathology

Background:

• Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract.
• The Ki-67 index is a marker of cellular proliferation and is associated with tumor aggressiveness.

Purpose of the Study:

• To investigate the correlations between the Ki-67 index and clinicopathological features and computerized tomography (CT) signs in GIST.
• To identify independent predictors of high Ki-67 expression in GIST patients.

Main Methods:

• Retrospective analysis of 186 GIST patients diagnosed via pathology and immunohistochemistry (IHC).
• Correlation analysis and univariate/multivariate logistic regression were used to assess relationships between CT signs, pathological features, and Ki-67 expression.
• Patients were stratified into Ki-67 ≤5% and >5% groups.

Main Results:

• Mitotic count, pathological grade, tumor hemorrhage, tumor necrosis, tumor size, and tumor density were associated with the Ki-67 index.
• Mitotic count, pathological grade, and tumor size were independently associated with high Ki-67 expression.
• The pathological features model demonstrated a better fit (C-index 0.876) than the CT signs model (C-index 0.697).

Conclusions:

• Mitotic count, pathological risk grading, and tumor size are independent risk factors for a high Ki-67 index in GIST.
• The Ki-67 index reflects tumor malignancy and can predict recurrence and metastasis.
• Pathological features are more predictive of Ki-67 expression than CT signs.