Significance of Circulating Epithelial Cell and Genetic Mutations in Long Term Follow-Up of Relapsed Papillary and Follicular Thyroid Carcinoma Patients

Persistent papillary and follicular thyroid carcinomas may present with locoregional or distant metastasis after a thyroidectomy. A lower percentage of well-differentiated thyroid carcinoma was diagnosed as relapsed after thyroidectomy and remnant ablation. In this retrospective study, relapsed cases were defined as those occurring 6 months after the initial thyroidectomy. The purpose of this study is to determine the prognosis of relapsed cases after multimodalities treatment. In addition, the time of relapse and prognostic factors were investigated. For the selected cases including relapsed cases, circulating epithelial cells (CECs) and BRAF mutation will be detected from peripheral blood and the tissue samples from initial thyroidectomy. In preliminary study, a total of 166 patients with relapsed disease were enrolled; the mean age was 45.8 ± 1.2 years, and 116 patients were women (69.9%). Among the relapsed cases, 95 cases (57.2%) underwent secondary locoregional resection for the recurrent tumors including 28 operations over twice. One hundred and sixty-four patients underwent 131I treatment for remnant ablation and further therapy. During the first 5 years, 59% of patients showed relapse. The longest period before relapse was 29.8 years. After the mean follow-up period of 12.7 ± 0.5 years, 37 (22.3%) patients had died of thyroid cancer. Multivariate analysis showed differences in age, male gender, and secondary primary cancer that were statistically significant between the disease-specific mortality and survival groups. Higher postoperative thyroglobulin levels predict shorter relapse periods. From these target subjects, 300 thyroid cancer patients and 60 control patients will be selected for CEC and BRAF mutation studies. In addition, CEC will be detected before and after rhTSH injection for 131I therapy. We anticipate relapsed papillary and follicular thyroid carcinoma presented with a relatively poor prognosis than control. The prognostic factors including CEC number will be analyzed.

Project ID:PC10608-1469
External Project ID:MOST106-2314-B182-042