Alphav integrin expression is a novel marker of poor prognosis in advanced-stage ovarian carcinoma

Abstract

Purpose: To analyze the possible correlation between expression of the alphav and beta1 integrin chains and survival in advanced-stage ovarian carcinomas, studying two patient groups with extremely different disease outcome.

Experimental design: Sections from 56 primary ovarian carcinomas and metastatic lesions from 34 patients diagnosed with advanced-stage ovarian carcinoma (Fédération Internationale des Gynaecologistes et Obstetristes stages III-IV), divided into long-term (16) and short-term (18) survivors, were evaluated for expression of alphav and beta1 integrin chains using mRNA in situ hybridization. Protein expression was additionally studied in 52 specimens using immunohistochemistry.

Results: The mean values for disease-free survival and overall survival were 115 and 132 months for long-term survivors, as compared with 4 and 23 months for short-term survivors, respectively. Expression of alphav integrin mRNA was observed in carcinoma (18 of 56; 32%) and stromal (17 of 56; 30%) cells. beta1 integrin mRNA was similarly detected in carcinoma (25 of 56; 47%) and stromal (19 of 56; 34%) cells. No significant differences were observed when primary and metastatic lesions were compared (P > 0.05). Alphav integrin mRNA was present more often in carcinoma cells in tumors of short-term survivors (P = 0.017 for carcinoma cells). In univariate survival analysis for all cases, alphav integrin mRNA expression in tumor cells correlated with poor survival (P = 0.012). This finding retained its predictive power in a multivariate survival analysis, in which all of the molecules studied previously in this patient cohort were included (P = 0.031). Immunohistochemistry confirmed the differences in alphav integrin expression in tumor cells of short-term as compared with long-term survivors, whereas beta1 integrin protein expression was comparable in the two groups.

Conclusions: To our best knowledge, this is the first evidence associating integrin expression with poor survival in ovarian carcinoma. Alphav integrin is, thus, a novel prognostic marker in advanced-stage ovarian carcinoma.