Calcitonin and Carcinoembryonic Antigen as Tumor Markers in Medullary Thyroid Carcinoma

Abstract

DeLellis, Ronald A., Rule, Allyn H., Spiler, Ira, Nathanson, Larry, Tashjian, Armen H., Jr., and Wolfe, Hubert J.: Calcitonin and carcinoembryonic antigen as tumor markers in medullary thyroid carcinoma. Am J Clin Pathol 70: 587–594, 1978. Six patients with locally advanced and/or metastatic medullary thyroid carcinoma, of both familial and non-familial types, had markedly elevated serum concentrations of calcitonin and carcinoembryonic antigen (CEA). The highest serum CEA concentrations were found in those patients with the most extensive disease and correlated with the extent of serum calcitonin elevation. Immunocytochemical studies revealed positive staining for CEA and calcitonin in tumor cells, and these results were confirmed by correlative radioimmunoassays of tumor extracts for CEA. Patterns of calcitonin and CEA immunoreactivity in tissue sections were similar but not identical. While most tumor cells contained both CEA and calcitonin, some groups of tumor cells that were strongly stained for calcitonin did not stain for CEA. In contrast to the granular staining pattern for calcitonin, CEA immunoreactivity tended to be diffusely distributed throughout the cytoplasm or was concentrated at the plasma membranes. Normal and hyperplastic C cells, on the other hand, showed strong staining for calcitonin but did not contain immunoreactive CEA. It is concluded that CEA is a useful tumor marker in patients with locally advanced or metastatic medullary thyroid carcinoma and that CEA and calcitonin can be produced by the same neoplastic cell populations.