Objective: Maspin is a member of the serine protease inhibitor superfamily. Experimental studies revealed that maspin suppresses tumor growth, angiogenesis, invasion and metastasis. We examined maspin expression in human ovarian tumors and relation between maspin expression and clinicopathological features as well as the role of maspin in predicting clinical outcome in patients with ovarian cancer.
Methods: Tissue samples consisted of 42 benign tumors, 10 borderline (LMP) tumors, 76 ovarian carcinomas, 8 Krukenberg tumors and 32 normal tissues. Immunoblot analysis was performed to evaluate the relative expression of maspin/beta-actin.
Results: Relative maspin level was significantly higher in patients with LMP tumors (median 0.74) and early stages ovarian cancers (median 0.46) when compared with healthy tissues (median 0.03), those with benign (median 0.23) and metastatic tumors (median 0.22). Overexpression of maspin was found to correlate with the early stage of the disease (p=0.001), non-serous subtype of ovarian cancer (p=0.03) and positive response to chemotherapy (p=0.02). A statistically significant longer PFS was seen in women with high as compared with low expression of maspin (p=0.03).
Conclusions: Maspin is upregulated in borderline tumors and the early stages of ovarian carcinoma and then significantly downregulated with malignant transformation. High expression may paradoxically promote the invasion and metastasis of ovarian carcinomas. Our study revealed that maspin expression could play an important role in predicting the results of treatment of ovarian cancer patients.