HISTOCYTOLOGIC GRADING OF MUCOEPIDERMOID CARCINOMA OF MAJOR SALIVARY-GLANDS IN PROGNOSIS AND SURVIVAL - A CLINICOPATHOLOGICAL AND FLOW CYTOMETRIC INVESTIGATION

Background. Controversy exists regarding the role of a 3-tiered gradin g system for mucoepidermoid carcinoma (MEG) of salivary glands in prog nosis and survival. This retrospective investigation evaluated a 3-tie red grading system modified from Healey by Batsakis and Luna and compa red various clinical, pathologic, and flow cytometric parameters and o verall survival among MECs of differing grades. Methods. Forty-eight p atients with 7 low-grade (LG), 23 intermediate-grade (IG), and 18 high -grade (HG) MECs of parotid (n = 43) and submandibular (n = 5) glands were studied. Data were analyzed using categorical statistics (Wilcoxo n, Kruskal-Wallis and Chi-squared tests where appropriate). Results. M ean ages were 42 years for patients with LG tumors; 47 years, IG; and 59 years, HG (p = 0.02). Gender ratio (p < 0.001) changed from female predominance in LG (6 F:1 M) and IG (2.1 F:1 M) to male predominance i n HG (3.5 M:1 F). Mean tumor stage was 1.4 LG, 2.4 IG, and 3.6 HG (p < 0.005). Tumor size increased from 2.1 cm for LG to 3.8 cm for HG (p = 0.01). Margins were involved by tumor in 0% LG, 44% IG, and 61% HG (p < 0.001). Lymph node involvement was 0% LG, 22% IG, and 72% HG (p < 0 .001). DNA aneuploidy (DNA index < 0.9 or > 1.1) was present in 0% LG, 13% IG, and 28% HG (p = 0.05). Proliferative fraction (S + G(2)M) was 5% LG, 7% IG, and 13% HG (p = 0.008). Radiotherapy was administered i n 14% LG, 35% IG, and 61% HG (p = 0.03). Recurrences (local and/or met astatic) occurred in 0% LG, 39% IG, and 61% HG (p = 0.009). Survival w as decreased significantly (p < 0.0001) with increasing tumor grade (1 00% LG, 70% IG, and 22% HG). Conclusion. Histologic grading of mucoepi dermoid carcinomas of major salivary glands, using the modified Healey 3-tiered system, correlates well with clinical, pathologic, and flow cytometric factors which influence the prognosis and overall survival in affected individuals. (C) 1995 John Wiley and Sons, Inc.