Comparative effectiveness of total thyroidectomy versus hemithyroidectomy for low-risk differentiated thyroid cancer: a multicenter retrospective cohort study with propensity score matching

<title>Abstract</title> Background The optimal surgical approach for patients with low-risk differentiated thyroid cancer (DTC) remains controversial. Current evidence comparing long-term outcomes between total thyroidectomy and hemithyroidectomy is limited by short follow-up periods and lack of comprehensive patient-reported outcomes. Objective To compare the comparative effectiveness of total thyroidectomy versus hemithyroidectomy in patients with low-risk DTC, evaluating oncologic outcomes, complications, quality of life, and healthcare costs. Methods We conducted a multicenter retrospective cohort study of 800 patients with low-risk DTC treated at four tertiary centers (2014–2023). Propensity score matching (1:1) was performed using age, gender, tumor size, histology, and BRAF V600E status. Primary outcomes were overall survival and recurrence-free survival. Secondary outcomes included complications, thyroid function, quality of life measures (HADS, SCL-90), and healthcare costs. Statistical analysis included Kaplan-Meier survival analysis with log-rank tests and Cox proportional hazards regression. Multiple comparisons were adjusted using Bonferroni correction. Results After propensity score matching, 400 patients were included in each group (median follow-up: 7.2 years, IQR: 5.1–8.9). The 8-year overall survival rates were 97.2% (95% CI: 95.6–98.8%) in the total thyroidectomy group versus 96.1% (95% CI: 94.2–97.9%) in the hemithyroidectomy group (HR 0.79, 95% CI: 0.44–1.42, p = 0.43). The 8-year recurrence-free survival rates were 96.8% versus 94.2% respectively (HR 1.48, 95% CI: 0.73–2.98, p = 0.28). Hemithyroidectomy was associated with significantly lower rates of permanent hypoparathyroidism (2.0% vs 8.0%, p &lt; 0.001, NNH = 17) and hypothyroidism (15% vs 100%, p &lt; 0.001). At one year post-surgery, fewer hemithyroidectomy patients experienced anxiety/depression (18% vs 25%, p = 0.018). Mean total healthcare costs over 8 years were significantly lower in the hemithyroidectomy group (¥28,247 vs ¥55,439, p &lt; 0.001). Conclusions For appropriately selected patients with low-risk DTC, hemithyroidectomy provides oncologic outcomes comparable to total thyroidectomy while offering advantages in terms of complications, thyroid function preservation, quality of life, and healthcare costs. Individual patient factors should guide treatment decisions through shared decision-making. These findings support consideration of de-escalated surgical approaches but require validation through prospective randomized trials.