Flow Cytometric DNA Analysis of Gastrointestinal Stromal Tumors

ABSTRACT

To evaluate the correlation between the histologic grade and DNA ploidy or proliferation index/S phase fraction (SPF) of gastrointestinal stromal tumors, we performed the DNA analysis using the flow cytometry. Paraffin embedded tissue samples of 57 gastrointestinal stromal tumors were used. The sites of the tumors were stomach (28), small intestine (23), and large intestine(6). DNA index, proliferative index, and SPF by the flow cytomery were compared with histologic grade. The histologic grade of the gastric tumors were benign (12), borderline (10), and malignant (6). Those of the small intestinal timors were benign (2), borderline (13), and malignant(8). The large intestine were borderline (2), and malignant (4). In stomach, aneuploidy was found in 25.0% of benign, 40.0% of borderline, and 100% of malignant. And there was statistically significant correlation between the histologic grade and ploidy (p < 0.05). By contrast, small and large intestinal tumors showed more frequent aneuploidy in benign than in malignant. The proliferative index was correlated with the histologic grade in gastric tumors (p<0.05), but the SPF was not. In conclusion, the ploidy and proliferative index of gastric tumors are closely correlated to the histologic grade. However, aneuploidy in tumors of the small and large intestine were difficult to predict the malignancy.