Expression of CD44 in effusions of patients diagnosed with serous ovarian carcinoma - diagnostic and prognostic implications

CD44 is a family of cell adhesion molecules involved in a variety of cellul ar functions. The present study analysed the expression of two CD44 isoform s in serous effusions of patients diagnosed with ovarian carcinoma and corr esponding primary and metastatic lesions. Fifty-eight effusions, 23 primary ovarian tumours, and 44 metastatic lesions were studied for protein expres sion of CD44s and v3-10 using immunohistochemistry. Results were correlated with clinical parameters. CD44v3-10 was seen in carcinoma cells in the maj ority of cases at all sites. Malignant effusions showed an up-regulation of CD44s compared to both primary tumours and metastatic solid lesions. Mesot helial cells frequently expressed CD44s, but were rarely immunoreactive for v3-10. CD44s immunoreactivity in cancer cells in effusions was significant ly more often observed in patients with FIGO stage 3 than in stage 4 patien ts (P = 0.045). Staining results did not correlate with age, effusion site, metastatic site, tumour grade or residual tumour mass after initial surger y. Likewise, comparison of overall and disease-free survival with expressio n of the CD44 isoforms studied did not reveal any statistically significant associations. The up-regulation in CD44 levels in effusions, primarily in stage 3 disease, suggests that adhesion of ovarian carcinoma cells to mesot helium may be regulated at the level of CD44s expression, and provides furt her evidence of phenotypic alteration in the transition from primary tumour cell clones to effusions. The similar expression profile of CD44 in carcin oma cells in peritoneal and pleural effusions supports our previous observa tions and the hypothesis that carcinoma cells in peritoneal effusions are t ruly metastatic.