Endocrine Abstracts

Backgrounds: Mutiplicity of papillary thyroid carcinoma (PTC) are not an unusual finding, although the origin of these foci is unclear. Either intraglandular metastases from a single dominant tumor or unrelated neoplastic clones were definitively proven as the means by which multicentric PTC form. In addition, there is insufficient clinical information concerning multicentric PTC presentation, prognosis, and long-term follow-up studies after treatment. Multiplicity of PTC has not been considered as an independent prognostic factor from a variety of tumor staging systems.

Aims: To evaluate whether that the presence of mulciplicity would be associated with tumor recurrence in PTC patients.

Methods: A total 249 PTC patients at a single institution who underwent total thyroidectomy and node dissection were retrospectively reviewed; the mean follow-up period was 2.8 years. Postoperative radioactive iodide ablation for thyroid remnant was performed after surgery for most patients.

Results: Of all the PTC cases reviewed, 85 cases (34%) were categorized as multicentric PTC. Compared with patients with unifocal PTC, multicentric PTC patients demonstrated higher cervical lymph node metastasis and tumor recurrence. Multiplicity was also significantly associated with tumor recurrence; 6 vs 1% with and without multiplicity, respectively (P=0.022 by log-rank test). However, this association was lost on multivariate analysis adjusting for conventional clinicopathological predictors of recurrence.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.