Background: There are several controversies between thyroid lobectomy and total thyroidectomy for surgical management of low-risk differentiated thyroid cancer (DTC) with a tumor diameter of 1– 4 cm.
Patients and Methods: In this study, we explore the factors related to selection of type of surgical procedure for 103 low-risk DTC patients with a tumor diameter of 1– 4 cm.
Results: Among 103 low-risk DTC patients with tumor diameters of 1– 4 cm, 43 patients underwent total thyroidectomy and 60 patients underwent thyroid lobectomy based on postoperative pathology. A ROC curve showed that the optimal diagnostic threshold for selecting surgical modality was a tumor diameter of 2.15 cm. For these low-risk DTC patients, the sensitivity and specificity for predicting thyroid lobectomy when tumor diameter < 2.15 cm while total thyroidectomy when tumor diameter ≥ 2.15 cm are 46.5% and 78.3%, respectively. There were significant differences between the selection of type of surgical procedure in patient groups with 1) tumors with multiple foci group vs a single focus (P < 0.05), and 2) tumor diameter of ≥ 2.15 cm vs < 2.15 cm (P < 0.05). There was no significant difference between gender and age groups (P > 0.05). Multivariate analysis confirmed that tumors with multiple foci and diameter ≥ 2.15 cm were the primary risk factors for implementation of total thyroidectomy (P < 0.05).
Conclusion: The diameter and multifocal nature of low-risk DTC tumors are the primary factors related to preferred surgical modality. This study revealed that thyroid lobectomy is more applicable to patients with tumor diameter < 2.15 cm and a single focus, whereas, total thyroidectomy was preferred in patients with tumor diameter ≥ 2.15 cm and/or multiple foci.
Keywords: differentiated thyroid cancer, cancer metastasis, operation type, factor analysis