Excellent Response to Therapy Occurs for Most Patients With Thyroid Cancer Treated With Lobectomy

American Thyroid Association (ATA) Guidelines for Management of Thyroid Nodules and Thyroid Cancer indicate that thyroid lobectomy (TL) or total thyroidectomy (TT) are appropriate surgery for low- and intermediate-risk well-differentiated thyroid carcinoma. We sought to determine outcomes of TL or TT by ATA response to therapy (RTT) classification.

This is a single-institution retrospective cohort study of adults with unilateral suspicious or malignant thyroid nodules under 4 cm from January 2016 through December 2021. Our primary outcome was ATA RTT.

During the study period, 118 met inclusion criteria: 37 (31%) underwent TL and 81 (69%) TT. Of the TL patients, 7 (19%) underwent completion thyroidectomy. Response to therapy (RTT) was similar with TT versus TL: excellent response 56 (69%) versus 30 (81%), indeterminate response 20 (25%) versus 5 (14%), and biochemically incomplete response 5 (6%) versus 2 (5%), P = 0.20. There were no differences between the groups for age, sex, race or ethnicity, tumor size, histologic type, or complications. Thyroidectomy (TT) was associated with multiple nodules 47% versus 22% for TL (P = 0.009), bilateral nodules 43% versus 16% (P = 0.004), central neck lymph nodes removed median 3 (interquartile range [IQR] 1-8) versus 0 (IQR 0-2) P < 0.001, lymph node metastases median 0 (IQR 0-1) versus 0 (0-0) P = 0.02. Median follow-up was 32.5 mo (IQR 17-56 mo) and was similar between the groups.

Patients with TL for well-differentiated thyroid carcinoma without high-risk features have an RTT similar to patients undergoing TT. In this cohort, 81% of patients treated with TL have not required additional intervention.