Prognostic value of matrix metalloproteinase-7 expression in patients with non-small cell lung cancer

The prognostic value of matrix metalloproteinase-7 (MMP-7) for survival of patients with non-small cell lung cancer (NSCLC) remains controversial. We performed a meta-analysis of the literatures to clarify its impact. Trials were selected for meta-analysis if they provided an independent assessment of MMP-7 in NSCLC and reported the analysis of survival data based on MMP-7 status. Pooled hazard ratio (HR) with 95 % confidence interval (95 % CI) was used to evaluate the associations between MMP-7 expression and survival of NSCLC patients. Heterogeneity and publication bias were also assessed. Seven studies involving 1,446 patients were identified. The combined HR for all studies was 1.28 (95 % CI 0.86–1.91; P?=?0.22). Subgroup analysis revealed that MMP-7 overexpression had a favorable impact on survival in Caucasians (HR?=?0.74; 95 % CI 0.55–0.99; P?=?0.043) but showed a poor survival prognosis in Asians (HR?=?1.74; 95 % CI 1.05–2.88, P?=?0.031). Its effect also appeared significant when the analysis was restricted to Asian patients with squamous cell cancer (HR?=?3.42; 95 % CI 1.92–6.11, P?=?0.000) and adenocarcinoma (HR?=?2.1; 95 % CI 1.34–3.29, P?=?0.001). Our meta-analysis suggests that there are ethnic differences in the clinical significance of MMP-7 expression for patients with NSCLC.