Background: Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a novel membrane-anchored matrix metalloproteinase inhibitor, and experimental studies have shown that RECK can suppress tumor progression through angiogenesis inhibition. We have already revealed that enhanced RECK expression is significantly correlated with a favorable prognosis in non-small-cell lung cancer (NSCLC). In this study, further analyses focused on pN2 disease were conducted to assess the clinical significance of RECK expression.
Methods: A total of 118 patients with completely resected pathologic stage IIIA N2 NSCLC were retrospectively examined. RECK expression in the primary tumor, along with involved N2 nodes, was examined immunohistochemically.
Results: RECK expression in the primary tumor was strong in 53 patients (44.9%) and was weak in the other 65 patients. The 5-year survival rate of patients with RECK-strong tumor (42.9%) was significantly higher than that of patients with RECK-weak tumor (23.1%; P = .017). Reduced RECK expression significantly correlated with a poor prognosis for patients with a single N2 node involved (P = .019), but not for patients with multiple N2 nodes involved (P = .440). A multivariate analysis confirmed that reduced RECK expression was an independent and significant factor to predict a poor prognosis (P = .031). RECK expression in involved N2 nodes was significantly higher than in primary tumors (P < .001).
Conclusions: RECK status was a novel prognostic factor in pathologic stage IIIA N2 NSCLC.