Patterns of Initial Recurrence in Completely Resected Papillary Thyroid Carcinoma

Background: Despite improvements in the surgical and medical treatment of papillary thyroid carcinoma (PTC), subsets of patients suffer from structural recurrence after initial treatment. This study evaluated the timing and patterns of recurrence in completely resected PTC patients. Methods: A retrospective review of a prospectively maintained thyroid cancer database was performed. The timing and patterns of recurrence were reviewed in 2250 patients with PTC >1 cm who achieved complete remission after total thyroidectomy and/or radioactive iodine treatment. Univariate and multivariate analyses were performed to identify factors predictive of recurrence patterns. Results: During 8.1 years of mean follow-up, 68 (3.0%) patients developed structural recurrences: 53 lymph node recurrences (LNR), 11 local soft tissue recurrences (LR), and four distant recurrences (DR). Two patients died of DR. Younger patients had a higher proportion of LNR, and older patients had a tendency toward LR/DR. LNR showed a peak incidence between one and three years after remission, but LR/DR showed a delayed peak incidence between two and four years. The factors that significantly increased the risk of LNR were multifocal tumor and lymph node metastasis (central/lateral). The factors that increased the risk of LR/DR were old age, large tumor size (>2 cm), and lateral lymph node metastasis. In addition, central neck dissection significantly reduced subsequent LR/DR. Conclusion: Patterns of recurrence after complete PTC resection are variable and associated with specific clinicopathologic factors. Understanding the timing and patterns of recurrence may lead to more effective adjuvant treatment and improved long-term follow-up strategies.