Related Experiment Video
Updated: Oct 10, 2025
Computer-Aided Three-Dimensional Visualization in the Treatment of Locally Advanced Thyroid Cancer
Published on: June 9, 2023
Optimal cutoff values of primary tumour size to better predict long-term outcomes in patients with papillary thyroid
Sung Woo Jang1, Jae Hyun Park1, Hyeong Ju Kwon2
1Division of Thyroid-Endocrine Surgery, Department of Surgery, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, South Korea.
Objective:
Primary tumour size (PTS) is known to be a significant prognostic factor in patients with papillary thyroid carcinoma (PTC) undergoing thyroidectomy. Although cutoff values of 2 and 4 cm are widely used in surgical extent decision and long-term outcomes predictions, the effectiveness of arbitrary cutoff values in stratifying patients for target outcomes is questionable. This study aimed to determine new optimal cutoffs of PTS.
Design, Patient And Measurements:
Patients (n = 529) with PTC who underwent total thyroidectomy were retrospectively reviewed. After risk factor analysis for structural recurrence, the optimal cutoffs of PTS were automatically calculated using restricted cubic spline analysis and X-tile software. Subgroups were classified based on the newly determined cutoff values. Both the recurrence-free survival (RFS) and the proportion of patients in each response-to-therapy category, using the dynamic risk stratification system (DRS), were compared between the subgroups.
Results:
PTS was confirmed as an independent risk factor for structural recurrence. The optimal cutoff values were calculated as 1.4 and 3.0 cm. The subgroups stratified using these newly determined cutoffs showed significantly different RFS and DRS based on the response to initial therapy, but the subgroups classified using the cutoffs of 2 and 4 cm did not.
Conclusions:
The newly determined cutoff values of PTS may be useful in better stratifying patients with PTC undergoing thyroidectomy for target outcomes and can be considered as a new definition in staging and risk stratification systems.
