Downregulation of MTSS1 expression is an independent prognosticator in squamous cell carcinoma of the lung

Background: The metastasis suppressor 1 (MTSS1) is a newly discovered protein putatively involved in tumour progression and metastasis. Material and Methods: Immunohistochemical expression of MTSS1 was analysed in 264 non-small-cell lung carcinomas (NSCLCs). Results: The metastasis suppressor 1 was significantly overexpressed in NSCLC compared with normal lung (P = 0.01). Within NSCLC, MTSS1 expression was inversely correlated with pT-stage (P = 0.019) and histological grading (P<0.001). NSCLC with MTSS1 downregulation (<20%) showed a significantly worse outcome (P = 0.007). This proved to be an independent prognostic factor in squamous cell carcinomas (SCCs; P = 0.041), especially in early cancer stages (P = 0.006). Conclusion: The metastasis suppressor 1 downregulation could thus serve as a stratifying marker for adjuvant therapy in early-stage SCC of the lung.