Total thyroidectomy versus lobectomy for intermediate-risk papillary thyroid carcinoma: A single-institution matched-pair analysis.

Background: Total thyroidectomy (TT) is recommended by guidelines for intermediate-risk papillary thyroid carcinoma (PTC) but its survival advantage over lobectomy has not been proven. The aim of this study was to examine the association between the extent of surgery and the clinical outcome of patients with intermediate-risk PTC.

Methods: Adult patients with PTC in the institutional database from 1996 to 2008 were retrospectively reviewed. Intermediate-risk patients were defined according to the 2015 American Thyroid Association (ATA) guidelines. Patients who underwent TT and patients who underwent lobectomy were then matched according to individual risk factors. Survival analysis was performed within the two paired groups, focusing on recurrence-free survival (RFS) and disease-specific survival (DSS) rates.

Results: Among 4230 PTC patients, 1087 intermediate-risk patients were included, in total 341 pairs were matched based on sex, age, primary size, clinical nodes (cN), extrathyroidal extension (ETE), pathological lateral neck metastasis (pN1b) and lymph node ratio (LNR). For these paired cases, with a median follow-up of 125 months (46-192), the lobectomy and TT groups were similar with respect to both 10-year RFS rate (77.4% vs 80.2%, log rank = 0.244, p = 0.622) and DSS rate (97.2% vs 98.4%, log rank = 0.351, p = 0.554). When excluding pairs of cases (62 pairs) who received radioiodine ablation (RAI), survival results were also similar in lobectomy and TT groups with respect to 10-year RFS rate (81.2% vs 83.1%, log rank = 0.63, p = 0.42) and DSS rate (97.3% vs 98.1%, log rank = 0.95, p = 0.33).

Conclusions: For intermediate-risk PTC, no advantages of TT over lobectomy were found with respect to RFS rate or DSS rate.