Long-term outcome of thyroid lobectomy for unilateral multifocal papillary carcinoma

The National Comprehensive Cancer Network (NCCN) guidelines recommend completion thyroidectomy for patients with multifocal papillary thyroid carcinoma (PTC) diagnosed by paraffin pathology after lobectomy. However, studies for the influence of surgical range on prognosis of unilateral multifocal carcinoma are scarce. We analyzed the clinicopathological characteristics and long-term outcomes of patients with unilateral multifocal PTC to identify risk factors for recurrence and disease-related death. The clinical and pathological data of 123 cases with multifocal lesions in the unilateral thyroid lobe were retrospectively collected, including sex, age, stage, surgical range, histopathology characteristics, and follow-up data. The prognostic factors were analyzed by means of the Kaplan–Meier method. The recurrence in the contralateral residual thyroid was observed in 6 cases. The 10-year cumulative recurrence rate of the remnant thyroid was 7.0%. Extrathyroidal extension (ETE) was a significant prognostic factor, with χ(2) equal to 4.043 and a P value of .044. One patient died from progression of pulmonary metastasis during the follow-up. The 10-year disease-specific survival rate was 96% and 14 cases experienced recurrences and underwent a second surgery (11.4%), and thus the 10-year recurrence-free survival rate was 83.2%. Multivariate analysis showed that the pathologic tumor (pT) stage was an independent prognostic factor for the recurrence-free survival rate (P <.0001, hazard ratio 2.871, 95% confidence interval 1.783–4.624). ETE is a significant prognostic factor for the recurrence of the remnant thyroid and pT stage is an independent prognostic factor for tumor recurrence-free survival. Lobectomy (with isthmectomy) is effective for most patients with unilateral multifocal PTC.