Assessment of proliferative activity in ovarian neoplasms by flow and static cytometry. Correlation with prognostic features.

We undertook a prospective flow and static cytometric study of proliferative activity in 74 malignant, borderline and benign ovarian neoplasms. Proliferative activity as assessed by S phase fraction (SPF), and immunostaining of tissue sections with Ki-67 antibody was compared with prognostically important clinicopathologic features. Malignant neoplasms had higher median percentage Ki-67 staining (27.6%) than borderline (12.3%) and benign (2.7%) tumors (P less than 0.05). Percentage Ki-67 staining correlated with SPF, DNA index, architectural grade, nucleolar grade, and mitotic count in malignant tumors; with nucleolar grade in benign tumors and with none of these variables in borderline tumors. Similarly, malignant neoplasms had a higher median SPF (11.5%) than borderline (3.4%) and benign (2.9%) neoplasms (P less than 0.05). In malignant neoplasms, SPF correlated with percentage Ki-67 staining, DNA index, age, and stage, but with none of these in borderline or benign neoplasms.