*3.1. Clinicopathological Characteristics of Included Patients*

The baseline characteristics of 718 patients are summarized in Table 1. The mean age was 46.8 ± 11.3 years at the time of surgery, and 603 of the patients (83.6%) were women. The mean follow-up period was 5.2 ± 2.6 years. Of the 718 enrolled patients, 115 patients (16.0%) underwent ipsilateral thyroid lobectomy, and 606 patients (84.0%) underwent total thyroidectomy. Patients in the total thyroidectomy group had a larger tumor size (0.8 ± 0.5 cm vs. 0.7 ± 0.4 cm; *p* = 0.047), a higher rate of ETE (55.6% vs. 40.0%; *p* = 0.002), and an increased risk of LN metastasis (33.0% vs. 22.6%; *p* = 0.028) compared with those in the lobectomy group. Coexisting Hashimoto thyroiditis was also more common in the total thyroidectomy group than in the lobectomy group (33.7% vs. 21.7%; *p* = 0.012). Other clinicopathological factors, including age, sex, and margin involvement, showed no significant differences between the groups.


**Table 1.** Comparison of clinicopathological characteristics between lobectomy and total thyroidectomy groups.

ETE, extrathyroidal extension; LN, lymph node; NA, not applicable.

Recurrences were observed in 8 patients (1.3%) in the total thyroidectomy group and 2 patients (1.7%) in the lobectomy group (*p* = 0.729). In the total thyroidectomy group, 7 patients developed ipsilateral neck LN recurrences, and thyroid bed recurrence was observed in the remaining patient. All recurrences in the lobectomy group were found in the ipsilateral lateral neck LN. The log-rank test indicated that the RFS of the total thyroidectomy group (*p* = 0.515) was comparable to that of the lobectomy group (Figure 1a).

**Figure 1.** Recurrence-free survival according to the operative extent in patients with multifocal PTCs, (**A**) before and (**B**) after propensity score matching.
