Objective: To evaluate the implication of Fletcher and Miettinen biologic potential grading criteria in native localized gastrointestinal stromal tumors (GISTs).
Methods: Two hundred and twenty localized GISTs with complete clinicopathologic and follow-up data were evaluated for their biologic potential by Fletcher and Miettinen grading criteria. The implication of the two grading criteria were compared by survival analysis.
Results: Evaluated by Fletcher grading criteria, the overall and disease-free survival rate of high risk GISTs was lower than that of very-low, low and intermediate GISTs; while the overall and disease-free survival rate of very-low, low and intermediate risk GISTs had no statistical diffence. In the high risk GISTs, the overall and disease-free survival rate of small intestinal and rectal GISTs was lower than that of gastric GISTs; while in the intermediate risk GISTs, the disease-free survival rate of small intestinal GISTs was lower than that of gastric GISTs. Evaluated by Miettinen grading criteria, the overall and disease-free survival rate of high risk GISTs was lower than that of very-low, low and intermediate GISTs; while the overall and disease-free survival rate of very-low, low and intermediate risk GISTs had no statistical difference. In the risk subgroup of GISTs, the overall and disease-free survival rate of gastric, small intestinal and rectal GISTs had no statistical difference.
Conclusions: Fletcher grading criteria is simple and easy to use; while Miettinen grading criteria for evaluating biological potential by anatomic site is more critical and has important reference implication for the selection of high risk patients for targeted adjuvant treatment.