Abstract LB-C06: Early prognostic significance of circulating laminin γ2-chain fragment in non-small-cell lung cancer
Authors: Teng Yu , Ma Li , Zhao Xiaoting , Zhang Lina , Gu Meng , Wang Yue , Yue Wentao 
Published: May 2016

Abstract
Background: Laminin γ2-chain (Ln-γ2), a distinctive subunit of heterotrimeric laminin-332, is frequently up-regulated in various types of carcinomas, and is of great importance in the biological processes including cell migration and tumor invasion. Despite of this, the status of circulating Ln-γ2 fragment in lung cancer patients is still uncertain. Methods: In this study, serum samples from 538 all-stage (stage I-IV) patients of non-small-cell lung cancer (NSCLC) and 94 age-matched normal volunteers were determined by enzyme-linked immunosorbent assay. Data were statistically analyzed in combination with clinicopathological information. Results: Compared to the normal controls, serum Ln-γ2 concentration is drastically increased in NSCLC patients (P &lt; 0.001), even in early cases of stage I patients (P &lt; 0.001). Furthermore, our data suggested that serum Ln-γ2 level was in close correlation to male gender (P &lt; 0.001) and smoking status (P &lt; 0.001) with a higher positive rate relative to each counterpart, but was not significant between adenocarcinoma and squamous cell carcinoma histologies (P = 0.879). We also found that circulating Ln-γ2 could reflect the progression of lung cancer with higher serum levels or positive rates in higher tumor-node-metastasis (TNM) stages. Survival analysis on 370 eligible patients who underwent a follow-up examination up to 4 years indicated that patients of serum Ln-γ2 positive group survived markedly shorter compared with those in the negative group (P = 0.028), and it was especially the case for clinical stage I (N = 72, P &lt; 0.001) and stage T1 (N = 67, P = 0.001), even for stage N0 patients (N = 148, P = 0.038), which all represent groups of early cases. As for the patients of advanced stages, however, it was not the case that the overall survival rates between Ln-γ2 positive and negative patients were not significantly different among clinical stages II-IV (P = 0.830), stages T2-4 (P = 0.575), stages N1-3 (P = 0.669), and stage M1 (P = 0.849) groups, respectively. Subsequently, Cox regression analysis was performed to define serum Ln-γ2 as an independent prognostic indicator in the all-stage NSCLC cases (N = 370, univariate, P = 0.035; multivariate, P = 0.007). Worthy of note, however, in the multivariate analysis on those more advanced cases (stage II-IV), no statistical significance was observed on the serum levels of Ln-γ2 (N = 298, P = 0.234). Conclusion: In summary, our study suggests circulating Ln-γ2 to be a promising diagnostic biomarker for early-stage NSCLC and an effective indicator of tumor progression. It is proposed that circulating Ln-γ2 might be important and applicable for the prognosis of early-stage NSCLC patients, rather than that of advanced cases.
Citation Format: Yu Teng, Li Ma, Xiaoting Zhao, Lina Zhang, Meng Gu, Yue Wang, Wentao Yue. Early prognostic significance of circulating laminin γ2-chain fragment in non-small-cell lung cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-C06.