Objective: Proliferative activity (PA) may be an indicator of a neoplasm's malignant potential, and it has been described as a prognostic factor in different malignant tumors. It was our aim to study the prognostic significance of PA defined by Ki-S5 and Ki-S2 immunohistochemical staining in a large homogeneously treated cohort with primary advanced-stage ovarian carcinomas.
Methods: Immunohistochemical detection of PA was performed using monoclonal Ki-S5 and Ki-S2 antibodies and standard immunostaining protocols. Kaplan-Meier survival analysis and Cox regression multivariate analysis were performed.
Results: High Ki-S5 PA was associated with a better prognosis. This finding was statistically significant after univariate and multivariate analysis. A similar trend was found in the subgroup of completely debulked patients. No prognostic effect of Ki-S2 PA could be detected in the present study.
Conclusion: High Ki-S5 PA is an indicator of a more favourable prognosis in patients with advanced ovarian carcinomas. Antiproliferative chemotherapy may be more effective in tumors which are highly proliferative, possibly due to an increased chemosensitivity.