Immunoreactivity for TIMP-2 is associated with a favorable prognosis in endometrial carcinoma

Tissue inhibitors of metalloproteinases are important regulators of metalloproteinase activity, and the balance of active enzyme and inhibitor is a critical determinant of tumor cell invasiveness. This study aimed to evaluate the prognostic and clinical implications of the two main inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, in endometrial carcinoma. The material consisted of 241 patients with primary endometrial carcinoma. The median follow-up time was 77 months. Expressions of TIMP-1 and TIMP-2 proteins were examined in paraffin-embedded tumor sections by immunohistochemical methods. Positive staining for TIMP-1 and -2 was observed in 88% and 86% of the primary tumors, respectively. The Kaplan-Meier analysis showed that the 5-year cancer-specific survival rate of the patients with TIMP-2 positive immunostaining was 89% and that of the TIMP-2 negative patients 78%. Positive immunoreaction for TIMP-2 correlated with favorable cancer-specific and overall survival. When including only endometrioid adenocarcinomas, a similar trend towards favorable survival was seen. Excluding stage IA carcinomas, the difference became again statistically significant. For TIMP-1, there was no statistically significant association with overall or cancer-specific survival. The Cox regression analysis showed stage, grade and TIMP-2 to be significant predictors of survival. We suggest that TIMP-2 may have a more important role in endometrial carcinoma progression than TIMP-1 and might serve as a potential marker for favorable prognosis in this type of cancer.