Objective: To study the expression and clinicopathologic significance of cancer stem cell markers CD44v6 and CD24 in ovarian serous carcinoma tissues.
Methods: One hundred and two cases of ovarian carcinoma diagnosed during the period from June, 2001 to December, 2010 were retrieved from archival files. The histology slides were reviewed and a two-tier system for grading of ovarian serous carcinoma was applied. The expression of CD44v6 and CD24 was detected by immunohistochemistry using EnVision method. The relationship between CD44v6/CD24 expression and various clinicopathologic parameters was analyzed.
Results: There were 46.1% (47/102) and 59.8% (61/102) cases expressing CD44v6 and CD24, respectively. Both CD44v6 and CD24 expression showed positive correlation with higher histopathologic grade (P = 0.003 and P < 0.05, respectively). CD24 expression also correlated with the presence of lymph node metastasis (P < 0.05). There was no statistically significant relationship between the expression of these two markers (χ(2) = 0.394, P = 0.530). The age of the patients, histopathologic grade, clinical stage and nodal status correlated with progression-free survival time (P < 0.05). CD44v6 expression and histopathologic grade correlated with the overall survival time (P < 0.05). Patient age was an independent poor prognostic factor by multivariate analysis.
Conclusions: CD44v6 expression, age older than 50 years, high clinical stage and presence of lymph node metastasis are associated with poor prognosis in patients with ovarian serous carcinoma. The two-tier system for grading of ovarian serous carcinoma is useful in predicting survival; and high tumor grade represents an important poor prognostic indicator for ovarian serous carcinoma.