Trial Information

Proper Extent of Surgery for Papillary Microcarcinoma

Study population From March 1986 to December 2006, a total of 5042 patients with PTC (of all
tumor sizes) underwent initial surgical therapy at our institution. Of these, 2441 patients
(48.4%) had PTMCs ≤ 1 cm in diameter, with 1270 undergoing TT and 1171 undergoing LT.
Complete follow-up data for major clinical events were available for 2014 patients (82.5%),
including 1015 (79.9%) of the TT group and 999 (85.3%) of the LT group (p=0.083). Patients
were followed-up for a median 11.8 years (range, 5 to 26 years). All histopathologic
diagnoses were reviewed and verified by endocrine pathologists using WHO criteria. The study
protocol was approved by our Institutional Review Board. Details of patients' presentations,
surgical and pathologic findings, and adjunctive treatments were obtained from the Yonsei
University Thyroid Cancer Database.

Management strategy In patients diagnosed with PTMC after a complete radiologic and
histologic examination, the extent of thyroidectomy and radioactive iodine (RI) therapy were
based on prognostic factors. However, the protocol of our institution as to how PTMC should
be appropriately managed has been changed according to update of clinical reports and
validated treatment guidelines. Therefore, the lack of a standardized approach during the
study period allowed us to assess the impact of various therapeutic modalities, especially
extent of thyroidectomy, in patients with PTMC.