Expression of Lamininγ2 in Extrahepatic Cholangiocarcinoma Tissues and its Influence on Tumor Invasion and Metastasis

Objective: To explore the expression of lamininγ2 in extrahepatic cholangiocarcinoma (EHCC) tissues andits influence on tumor invasion and metastasis. Materials and
Methods: Paraffin embedding samples of cancer,para-cancer, lymph node metastatic and hepatic metastatic tissues from 79 patients undergoing EHCC resectionwere collected. Expression of lamininγ2 was detected by immunohistochemistry and its relationship with clinicalpathological characteristics and the prognosis of EHCC patients were analyzed.
Results: Lamininγ2 showednegative staining in para-cancer tissues, but demonstrated a 51.9% (41/79) positive expression rate in extracellularmatrix (ECM) or cytoplasm of EHCC tissues. In lymph node metastatic and distant metastatic nidi, expressionof lamininγ2 was significantly higher than in the primary nidi (χ2=7.4173, P=0.0065; χ2=4.0077, P=0.0453). Theexpression was in obvious association with lymph node metastasis (P<0.01), but had no relevance with age, gender,tumor location, tumor stage, differentiation and distant metastasis in ECM (P>0.05), whereas it was in markedconnection with lymph node and distant metastasis (P<0.05 or P<0.01), but had no relationship with age, gender,tumor location, tumor stage and differentiation in cytoplasm (P>0.05). However, the median survival time andmedian recurrent period of patients with positive expression of lamininγ2 in both cytoplasm and ECM of tumorcells, only in ECM and only in cytoplasm, were evidently lower than with negative expression of lamininγ2 inRCM and cytoplasm (P<0.05 or P<0.01). Further Cox regression analysis showed that the positive expressionof lamininγ2 and the tumor differentiation were independent risk factors influencing the prognosis of EHCCpatients.
Conclusions: Abnormal expression of lamininγ2 may be closely associated with invasion and metastasisof tumor cells, and thus a potential molecular marker for prognosis of EHCC patients.