Aims: To determine the diagnostic and prognostic value of the immunohistochemical analysis of CD44 variants in benign borderline and malignant tumours of the ovary.
Methods and results: The reactivity of tumour cells with three monoclonal antibodies, respectively, directed to all CD44 variants, CD44-v3 isoform and CD44-v6 isoform, was assessed by using an indirect immunoperoxidase technique applied to formalin-fixed, paraffin-embedded samples of 36 cases of borderline, as compared to 20 cases of benign tumours and 20 cases of carcinomas. CD44 variants were detected in 97% of borderline tumours, as compared to 60% of benign tumours and 100% of carcinomas. CD44-v3 was detected in 25% of borderline tumours, as compared to 0% of benign tumours (P = 0.003) and 55% of carcinomas (P = 0.065). The expression of CD44-v6 was detected in 28% of borderline tumours, as compared to 20% of benign tumours and 30% of carcinomas. In borderline tumours, as in carcinomas, CD44-v6, but not CD44-v3, expression was correlated with an increased proliferative index and with a higher incidence of p53 expression.
Conclusion: Borderline tumours of the ovary present frequent quantitative and qualitative alterations in the pattern of expression of CD44 proteins. However, these alterations are unlikely to represent useful diagnostic or prognostic markers.