Expression of nm23 protein in adult soft tissue sarcoma is correlated with histological grade

BACKGROUND: There is controversy about whether expression of nm23 is involved in suppression of metastases or contributes to tumour progression. Few studies have examined the role of nm23 in sarcomas. The aim of this study was to determine if expression of nm23 protein or its H1-subtype correlated with clinicopathological parameters in adult soft tissue sarcomas (STS). MATERIALS AND METHODS: Protein expression was examined by immunohistochemistry on paraffin-embedded sections of 46 STS patients, quantified using a colour video imaging system and correlated to histological grade. The monoclonal antibodies used were anti-nm23 (recognising both nm23-H1 and nm23-H2) and anti-nm23-H1 (recognising nm23-H1 only). RESULTS: High-grade tumours significantly overexpressed nm23 (including both nm23-H1 and nm23-H2) compared with both intermediate and low-grade tumours (ANOVA and Tukey, all p < 0.05). Multiple regression analysis confirmed the significance of the relationship and independence of the nm23 (p = 0.005), but not nm23-H1. CONCLUSION: Expression of nm23 protein, particularly nm23-H2, is an independent predictor of malignant potential of adult STS.