Expression and significance of c-met protein in papillary thyroid carcinoma.

The c-met protein, encoded by the c-met oncogene and its ligand, the hepatocellular growth factor/scatter factor, are known to be responsible for the motility and mitogenesis of epithelial cells including cancer cells. Recent studies have reported the prognostic significance of the c-met protein in malignant tumors. Papillary thyroid carcinoma, the most common histological type of thyroid carcinoma, can easily metastasize to regional lymph nodes, reflecting the activated motility and invasiveness of the carcinoma cells. We examined the expression of c-met protein in papillary thyroid carcinomas to assess its significance. Immunohistochemical staining of the c-met protein was performed on archival materials. The c-met protein was expressed in 10 cases of papillary thyroid carcinoma with recurrence, and in 5 of 10 cases without recurrence. Normal thyroids were negative for c-met protein. Expression of the c-met protein was statistically associated with recurrence of the thyroid carcinoma (p = 0.016). It is suggested that expression of the c-met protein plays a role in the recurrence of papillary thyroid carcinoma.