Pathogenesis and Treatment of Thyroid Carcinoma

During the past decade we have helped develop a computerized database that includes details about the presentation, therapy and outcome of 2,300 patients with differentiated thyroid carcinoma (DTC) who had initial treatment at Mayo. These patients and their tumor tissues (both archival and fresh-frozen) are the substrate for a series of cooperative investigations designed to: (1) provide further information about the molecular pathogenesis of such tumors, (2) help identify the minority of patients at risk of death, and (3) define a rational management program for both initial therapy and subsequent follow-up.

A series of studies performed with Dr. R. B. Jenkins of Mayo's molecular cytogenetics laboratory and Drs. G. Vecchio and M. Santoro of Naples, Italy, have helped clarify the role of the PTC oncogene in papillary carcinoma. They also point to the participation of a possible tumor-suppressor gene on chromosome 3p in the development of follicular and Hurthle cell carcinoma. This work is continuing in Dr. N. Eberhardt's laboratory at Mayo, where attempts are being made to localize a 3p-based anti-oncogene and clone it.

We have published outcome results of patients with papillary (PTC), follicular (FTC), and medullary (MTC) carcinomas and have identified by multivariate analyses the independently significant prognostic factors. Scoring methods for predicting outcome in PTC and MTC have been devised, and similar work on FTC continues.

Presently, we are trying to define the optimal extent of primary surgical resection and, in patients with either PTC or FTC who are undergoing definitive surgery, to clarify the role of radioiodine remnant ablation. When the retrospective analyses have been completed, further prospective studies will be designed in an attempt to definitively answer remaining therapeutic questions.