Background
The incidence of thyroid cancer has dramatically increased over the last few decades, and up to 87% of patients have multifocal tumors. However, the prognostic impact of multifocality in patients with papillary thyroid carcinoma (PTC) remains controversial. In this study, we investigated the role of tumor multifocality in clinical outcomes of PTC.
Methods
Study subjects included 1937 patients who underwent thyroidectomy for PTC between March 2009 and December 2019. Data collected included patient demographics, pathologic features including multifocality, development of recurrence, and follow up period.
Results
Multifocality was found in 591 patients (30.4%) and mean follow up period of 5.2 ± 2.8 years. The 5-year recurrence free survival (RFS) rate was 96.4% in patients with multifocal tumors, whereas those with unifocal disease showed 98.3% of 5-year RFS (p = 0.001). Multivariate Cox regression analysis indicated that tumor size (HR 1.83, 95% CI 1.36-2.45), LN metastasis (HR for N1a 3.12, 95% CI 1.42-6.84; HR for N1b 4.24 95% CI 1.20-15.0), and multifocality (HR 2.11, 95% CI 1.14-3.89) were independent predictors of recurrence.
Conclusions
Our data suggest that multifocality increases the risk of recurrence in patients with PTC. Patients with multifocal PTCs require careful treatment and follow-up approaches.