The expression of versican and its role in pancreatic neuroendocrine tumors.

Background: Pancreatic neuroendocrine tumors (pNET) are rare and heterogeneous. New biomarkers are needed for better predicting the prognosis and for providing individualized treatment. Versican (VCAN) plays an important role in tumorigenesis. Therefore, we plan to investigate the role of VCAN in pNET prognosis.

Method: The clinical and pathological data of pNET patients who underwent surgery between 2005 and 2010 were collected and evaluated. Radiologic tumor assessments with contrast computed tomography or magnetic resonance imaging were performed at baseline and follow up. The radiologic response was classified according to the RECIST 1.1 criteria. VCAN expression was assessed by immunohistochemical staining (IHC).

Result: Among 155 pNET patients, 112 (72.3%) pNET patients were VCAN positive, and 43 (27.7%) were negative. Positive expression of VCAN in pNET was significantly associated with a longer disease-free survival (DFS) compared with VCAN negative pNET (p = 0.038, HR 0.462, 95% CI 0.218-0.978). Subgroup analysis showed that VCAN positive expression was associated with a longer DFS in the G1 subgroup (p = 0.031, HR 0.124, 95% CI 0.013-1.193), the tumor size>2 cm subgroup (p = 0.047, HR 0.458, 95% CI 0.207-1.012) and the NF-pNET subgroup (p = 0.003, HR 0.274, 95% CI 0.112-0.673). Multivariable analysis showed that VCAN negative expression, G2 and tumor size>2 cm were independent factors of poor prognosis of pNET (p = 0.041, p < 0.001, p = 0.008, respectively).

Conclusion: Our data indicate that VCAN positive expression may serve as an independent factor of predicting DFS in pNET; its expression in pNET tissues was correlated with a longer DFS.