Comparison of the intratumor DNA ploidy distribution pattern between differentiated and undifferentiated gastric carcinoma

OBJECTIVE: To compare the differences in intratumor DNA ploidy distribution pattern between differentiated and undifferentiated carcinoma of the stoma ch. STUDY DESIGN: Two hundred five cases of surgically resected gastric carcino ma were studied, comprising 125 differentiated and 80 undifferentiated carc inomas. DNA ploidy was determined by means of flow cytometry in stepwise se ctions of the entire tumor. The intratumor DNA ploidy distribution pattern was compared between these two histologic types. RESULTS: Differentiated carcinomas comprised 35 cases of predominantly dipl oid (28%) and 90 cases of predominantly aneuploid (72%) tumors, while undif ferentiated carcinomas comprised 46 cases of predominantly diploid (57.5%) and 34 cases of predominantly aneuploid (42.5%) (P < .01). The frequency of cases showing predominantly aneuploidy among the differentiated carcinomas was significantly higher than among the undifferentiated carcinomas at sta ges IA and IIIA. The rate of cases showing heterogeneity was lower among th e early-stage cases than among the advanced-stage cases in both histologic types. Among the differentiated carcinomas, there were 22 cases that had mo ve than six DNA stemlines in each tumor, whereas among undifferentiated car cinomas, there were sh such cases (P < .05). CONCLUSION: There were more cases with high malignant potential among the d ifferentiated carcinoma cases than among the undifferentiated carcinoma cas es in the present series.