Indicators of proliferation and invasion in ovarian tumors of low malignant potential

Objective: We analyzed tumor biologic indicators of invasion and proliferat ion in ovarian tumors of low malignant potential (LMP) and in benign and ma lignant ovarian tumors. Methods: Clinical and tumor-related data were collected prospectively in 51 patients with ovarian tumors of LMP between 1983 and 1997. The antigens uP A and PAI-1 were measured by ELISA in 36 LMP tumors, 34 FIGO stage I ovaria n carcinomas, and 20 ovarian cystadenomas. DNA ploidy and S-phase fraction were measured with flow cytometry in formalin-fixated paraffin-embedded sec tions in 48 LMP tumors in 19 stage I carcinomas. Results: The median uPA content in LMP tumors differed significantly from t hat in the carcinomas and cystadenomas (0.50 vs. 0.97 and 0.23 ng/mg protei n, respectively; P < 0.02). The median PAI-I content in three groups was 6. 92, 7.34 and 4.50 ng/mg protein, respectively, the difference between carci nomas and cystadenomas was statistically significant (P < 0.05). The rate o f DNA aneuploidy was 9.8% in the LMP tumors and 18.4% in the carcinomas (:P < 0.01). The S-phase fractions did not differ significantly between the gr oups. Conclusions: Ovarian tumors of LMP differ from benign and malignant ovarian tumors in tumor biologic criteria of invasion and proliferation.