Neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9) prognostic value in lung adenocarcinoma

Prognosis in patients with lung cancer is poor. Neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9) are proteins involved in the invasion and metastases of cancer. The objective of this study is to determine if there is a relationship between tumor expression of NGAL and MMP-9 in lung adenocarcinoma patients with prognosis and overall survival. Retrospective analysis was made of patients with lung adenocarcinoma treated at Medica Sur Hospital between 2005 and 2013. Tumor tissue was analyzed for NGAL and MMP-9 expression by immunohistochemistry. We identified 41 patients. Mean overexpression in tumoral tissue of NGAL was 70 % and 30 % for MMP-9. Univariate analysis revealed that prognostic factors associated with overall survival (OS) were NGAL expression and stage at diagnosis. Median OS for NGAL expression <70 % was 45.7 months (95 % CI; 15.2–76.2) and for patients with ≥70 % 4.6 months (95 % CI; 0.5–18.8; P < 0.0001), and for stage at diagnosis (stages I and II mean not reached), stage III mean OS 15.57 months (95 % CI; 9.8–21.2) and stage IV 9.6 months (95 % CI; 0.8–18.4. P = 0.002). No differences in OS were found for expression of MMP-9. Multivariate analysis revealed significance for OS in NGAL expression (HR 5.01 [95 % CI; 1.68–14.93] P = 0.004) and stage at diagnosis (HR 2.05 [95 % CI 1.30–3.22] P = 0.002). Tumoral tissue expression of NGAL ≥70 % confers a worse prognosis compared to those who did not. NGAL is an independent prognostic factor of stage at diagnosis.