Total thyroidectomy or hemithyroidectomy for differentiated thyroid carcinoma?

[BACKGROUND] Optimal surgical management for differentiated thyroid cancer (DTC) remains controversial, particularly regarding initial hemithyroidectomy versus total thyroidectomy. Understanding factors predicting the need for completion thyroidectomy and residual disease in the remnant lobe is critical for risk-adapted treatment.

[METHODS] We conducted a multicentre retrospective cohort study of 387 patients undergoing surgical management of DTC between 2015 and 2024 across three tertiary centres. Demographic, clinical, cytological, and pathological data were extracted and compared by surgical extent. Among patients initially treated with hemithyroidectomy, predictors of proceeding to completion thyroidectomy were assessed. In patients undergoing completion thyroidectomy, clinicopathological factors associated with residual disease in the completion lobe were identified using both univariate and multivariate logistic regression analyses.

[RESULTS] Of 387 patients (median age 44 years, 78.0% female), 243 (63.0%) initially underwent hemithyroidectomy, and 143 (37.0%) underwent total thyroidectomy. Among hemithyroidectomy patients, 174 (71.3%) proceeded to completion thyroidectomy. Among completion thyroidectomy patients, residual disease was found in 63 (36.2%). Those undergoing completion thyroidectomy were more likely to have larger tumour (p < 0.001), nodal disease (0.006), extrathyroidal spread (0.003) and lymphovascular invasion (0.004). On multivariate analysis, male sex (OR 4.20, 95% CI [1.13, 15.63], p = 0.034) was independently associated with higher odds of residual disease in the completion lobe, while papillary subtype was associated with a lower odds of residual disease (OR 0.12, 95% CI [0.03, 0.50], p = 0.0045).

[CONCLUSION] Larger nodule size and adverse pathological features were associated with higher rates of completion thyroidectomy. Among patients undergoing completion surgery, male sex independently predicted residual disease (OR 4.20, p = 0.034), while papillary histology was associated with a reduced risk (OR 0.12, p = 0.0045). These findings support risk-adapted surgical strategies and highlight the need for individualised decision-making and further prospective research to refine risk prediction in DTC.