Stromelysin-2 overexpression in human esophageal squamous cell carcinoma: potential clinical implications

The degradation of the extracellular matrix (ECM) is a major step in the process of tumor invasion and metastasis, mediated by matrix metalloproteinases (MMPs). Knowledge of alterations in the expression of stromelysin-2 (ST-2) or MMP-10 in human esophageal squamous cell carcinoma (ESCC) is meager. Immumohistochemical analysis of ST-2 expression was carried out in surgically resected ESCCs (50 cases) and paired distal histologically normal esophageal tissues (50 cases), correlated with clinicopathological parameters. Overexpression of ST-2 protein, in tumor cell cytoplasm and stromal elements, was observed in 37 of the 50 (74%) ESCCs localized in tumor cell cytoplasm and stromal elements. Low levels of ST-2 were observed in 8 of the 50 (16%) matched histologically normal esophageal tissues. Significant associations were observed between ST-2 overexpression and tumor size (r = 0.02, P = 0.04), local invasiveness of the tumor (r = -0.30, P = 0.002) and distant organ metastasis (r = -0.227, P = 0.02), suggestive of its involvement in development and progression of ESCCs. The data underscore the significance of ST-2 expression in context to the aggressive tumor characteristics observed in ESCCs in the Indian population, wherein extremely poor prognosis has been ascribed to extensive local invasion and metastasis. (C) 2002 International Society for Preventive Oncology. Published by Elsevier Science Ltd. All rights reserved.