Importance of histologic grading in the prognosis of epithelial ovarian carcinoma.

Ovarian epithelial carcinomas still have a poor prognosis. Great efforts are being made to improve treatment modalities; chemotherapy in particular is in a period of dynamic development. A basic requirement for the necessary research is a thorough knowledge of the natural history of ovarian cancer and its prognostic influence. In this report the importance of tumor stage, histologic type, and degree of differentiation is analyzed in an unselected and well-controlled Swedish ovarian cancer series comprising 501 cases. The great prognostic significance of tumor grade for survival is demonstrated and it is proposed that this histopathologic factor, as well as tumor stage and histologic type, should be included in the international classification of primary epithelial tumors of the ovary.