Abstract:Objective:To investigate protein expression and significance of vascular endothelial growth factor-C (VEGF-C) in differentiated thyroid cancer(DTC) and its relationship with clinicopathologic features. Methods:The expression of VEGF-C in 50 papillary thyroid cancer(PTC),50 follicular thyroid cancer(FTC) and 20 normal thyroid (NT) tissue specimens were detected by SP immunohistochemistry. Results:The positive rates of VEGF-C in PTC,FTC and NT tissues were significantly different (48.0% vs 24.0% vs 10.0%,P < 0.05). The positive rates of VEGF-C were higher in PTC with lymph node metastases than PTC without metastases and PTC with bone or lung metastases(85.7% vs 40.0% or 50.0%,P < 0.05). The positive rates of VEGF-C were higher in FTC with lymph node metastases than FTC without metastases and FTC with bone or lung metastases (57.1% vs 17.1% or 25.0%,P < 0.05). The difference between PTC and FTC was mainly found between groups without metastases and with bone or lung metastases(P < 0.05). Conclusion:VEGF-C is closely related to lymph node metastasis of DTC,and may play an important role in lymph node metastasis of DTC. The expression of VEGF-C is higher in PTC than FTC,and can explain the different propensities to lymph node metastasis of PTC and FTC. High expression of VEGF-C in tumor tissue may be a predictor of lymph node metastasis of DTC.