IMP3 expression in borderline tumors of the ovary

Abstract

Background/Aim: Borderline ovarian tumors (BOTs) have a less aggressive behavior than invasive epithelial ovarian tumors. Still some patients relapse or succumb to disease. Molecular markers that reliably predict prognosis are lacking. Insulin-like growth factor II mRNA-binding protein (IMP3) has been suggested as a prognostic marker in colorectal, hepatocellular, and ovarian clear-cell carcinomas. Materials and Methods: We analyzed the expression of IMP3 by immunohistochemistry in a cohort of 140 BOT and its association with histopathological features. Results: We found no association of IMP3 expression with patients' age, FIGO stage, microinvasion, and presence of implants. In contrast, IMP3 expression correlated to mucinous subtype of BOTs (42.2% vs. 9.5% among other subtypes) (p<0.001). IMP3 expression was found to be associated with the presence of in situ carcinoma in MBOT, but not in other subtypes (p=0.021). Conclusion: Expression of IMP3 in BOT is associated with the mucinous subtype and may serve as an early indicator for the development of malignant features.