Expression of integrin αvβ3 in medullary thyroid carcinoma.

Aim: Tumor markers often remain elevated after intended curative resection of medullary thyroid carcinoma (MTC). The aim of this study was to determine the expression of α_vβ₃, a promising theranostics target, in MTC and its metastases. Materials & methods: A_vβ₃ expression was analyzed in 104 patients using a tissue microarray and correlated with clinicopathological variables and survival. Results: Cytoplasmic α_vβ₃ positivity was seen in 70 patients and was associated with lymph node metastases at time of initial surgery. Membranous positivity was considered positive in 30 patients and was associated with sporadic MTC. Conclusion: A_vβ₃ was expressed in the cytoplasm of 67% of MTC patients. Membranous expression, which is presumably most relevant for the theranostic use of α_vβ₃, was seen in 29%. Article highlights After intended curative resection of medullary thyroid carcinoma (MTC), calcitonin levels often remain elevated indicating remnant disease or metastasis. There is a demand for new imaging and therapeutic options for patients with MTC. A_vβ₃, an integrin expressed in many tumors, is a promising target for nuclear imaging and treatment using radiolabeled arginine-glycine-aspartic acid (RGD). Cytoplasmic and membranous α_vβ₃ expression was analyzed using a tissue microarray including primary tumors and lymph node metastases of 104 and 27 patients, respectively. Cytoplasmic expression was considered positive in 67% of patients and was associated with lymph node metastases at the time of initial surgery. Membranous expression, which is thought to be most relevant for the theranostic use of α_vβ, was seen in 29% of patients and was associated with sporadic MTC. Survival analysis showed no prognostic value of α_vβ₃. The correlation of immunohistochemical α_vβ₃ expression and uptake of radiolabeled RGD should be further assessed in patients with membranous α_vβ₃ expression. [ABSTRACT FROM AUTHOR]