Prognostic value of histologic grading of ovarian carcinomas.

Histologic grading of ovarian carcinomas has prognostic and therapeutic relevance, but although several grading systems have been proposed, no universal grading system has been established. Silverberg's group has recently proposed a simple histologic grading system of ovarian carcinomas. We studied its prognostic value in 70 patients with invasive ovarian carcinomas and compared it with that of histologic typing and clinical staging. Kaplan-Meier survival curves showed the following 5-year survival rate using the Silverberg grading system: grade I (n=21) 91%, grade II (n=20) 64%, grade III (n=29) 38% (p<0.001). Multivariate analysis indicated that the histologic grade, the clinical stage, and clear cell histologic type were significant prognostic factors. The Silverberg histologic grade correlated well with prognosis for all histologic types of ovarian carcinomas except for clear cell carcinoma. It is simple, reproducible, and provides useful prognostic information.