Reduced decorin expression in the tumor stroma correlates with tumor proliferation and predicts poor prognosis in patients with I-IIIA non-small cell lung cancer.

Abstract

Decorin, chiefly synthesized by tumor stroma, is known as a tumor suppressor. However, the clinical and prognostic significance in lung cancer remained unclear. Here, decorin and Ki67 expression was detected by immunohistochemistry (IHC) in I-IIIA non-small cell lung cancer (NSCLC) tissues (n=264) in comparison to adjacent normal tissues (n=40). The relationship between the expression of decorin and clinical characteristics, as well as Ki67 index and prognosis, was analyzed. Decorin expression was decreased in both the stroma (P<0.001) and the tumor cells (P=0.038) in NSCLC specimens. There was the lowest stromal expression of decorin in patients with G3 adenocarcinoma and higher Ki67 index in the stromal decorin-negative group. The Kaplan-Meier survival analysis demonstrated that lack of decorin in the stroma was correlated with a shorter DFS and OS (P=0.005 and P=0.010, respectively), while there was no significant association between decorin expression in the tumor cells and outcome. Multivariate analysis showed that reduced expression of decorin in the stroma was an independent prognostic factor for poor outcome including DFS (HR=5.685, 95% CI 0.493-0.933; P=0.017) and OS (HR=6.579, 95% CI 0.484-0.908; P=0.010). Negative decorin in the stroma combined with high Ki67 index predicted poorer outcomes for I-IIIA NSCLC patients. Our results provide data on decorin expression in both the stroma and cancer cells in NSCLC and reveal that reduced expression of stromal decorin correlates with high Ki67 index and has prognostic significance for poor outcome in I-IIIA NSCLC. Our data suggest that evaluating stromal decorin expression might be useful in assessing the prognosis and malignant potential.