Comparable survival after lobectomy and total thyroidectomy for T3b differentiated thyroid carcinoma: A...

Area of Science:

• Oncology
• Surgical Oncology
• Endocrinology

Background:

• Current 2025 American Thyroid Association guidelines recommend total thyroidectomy for all T3b differentiated thyroid carcinoma (DTC).
• The prognostic significance of surgical extent in T3b DTC is not well-established.
• This study investigates the relationship between surgical approach and survival in T3b DTC.

Purpose of the Study:

• To evaluate the association between surgical approach (total thyroidectomy vs. lobectomy) and survival outcomes in T3b DTC patients.
• To determine the relative importance of surgical extent compared to other prognostic factors.
• To assess survival equivalence across different tumor sizes and nodal statuses.

Main Methods:

• Analysis of 6,920 T3b DTC patients from the SEER database (2004-2022).
• Variable importance assessed using SHAP values and Random Survival Forests.
• Multivariable Cox regression and Fine-Gray models used for survival analyses, considering overall survival and disease-specific survival.

Main Results:

• Surgical approach had minimal predictive value for outcomes, less than age, tumor size, and nodal status.
• Lobectomy demonstrated equivalent overall survival to total thyroidectomy (adjusted HR 0.96, 95% CI 0.68-1.37).
• Survival equivalence was consistent across tumor size and nodal status subgroups; favorable-risk patients exceeded 96% disease-specific survival.

Conclusions:

• Surgical extent appears to have a limited impact on survival for T3b DTC.
• Lobectomy may be a suitable option for carefully selected T3b DTC patients.
• Individualized treatment strategies, rather than universal total thyroidectomy, are supported for T3b DTC.