Thyroid lobectomy is not sufficient for T2 papillary thyroid cancers.

Area of Science:

• Oncology
• Surgical Oncology
• Epidemiology

Background:

• Histologic subtypes of papillary thyroid cancer (PTC) influence patient prognosis.
• Tumor size and surgical approach are critical factors in PTC outcomes.

Purpose of the Study:

• To investigate the impact of surgical extent on survival in conventional versus follicular-variant PTC.
• To stratify the analysis by tumor size (1.0-3.9 cm) for both subtypes.

Main Methods:

• Retrospective analysis of 33,816 adult patients with PTC (1.0-3.9 cm) from the National Cancer Data Base (2004-2008).
• Patients were categorized by histologic subtype (conventional vs. follicular-variant) and extent of surgery (total thyroidectomy vs. lobectomy).
• Cox regression models, stratified by tumor size, assessed the association between surgical extent and overall survival.

Main Results:

• Total thyroidectomy was linked to improved survival in conventional PTC (P=0.02), but not in follicular-variant PTC (P=0.42).
• For conventional PTC, total thyroidectomy improved survival for tumors 2.0-3.9 cm (P=0.03), but not for 1.0-1.9 cm tumors (P=0.16).
• Follicular-variant PTC showed equivalent survival between lobectomy and total thyroidectomy for both 1.0-1.9 cm (P=0.45) and 2.0-3.9 cm (P=0.88) tumors.

Conclusions:

• Tumor size, histologic subtype, and surgical therapy are key determinants of PTC survival.
• Total thyroidectomy offers survival benefits for conventional PTC with tumors measuring 2.0-3.9 cm.
• Total thyroidectomy should be considered for 2.0-3.9 cm PTC when preoperative molecular analysis is unavailable to differentiate subtypes.