Risk factors for persistent disease in papillary thyroid carcinoma with lymph node metastasis

It is known that the presence of neck lymph node (LN) metastasis is correlated with persistent disease in papillary thyroid carcinoma (PTC) patients. After appropriate therapy, most patients become disease free, whereas some may still have persistent disease. The present study aimed to determine the potential variables affecting the clinical course of the disease and persistent disease patterns in PTC patients with LN metastasis.

The study group included consecutive PTC patients with LN metastasis. Clinicopathological characteristics and persistent disease pattern during the follow-up period were examined to identify risk factors for persistent disease using univariate and multivariate analyses.

At the end of a median follow-up of 84 months, 90 (69%) patients became disease free and 40 (31%) patients had persistent disease. Univariate analysis showed that male sex, older age at initial diagnose (≥45 years), larger tumor size (>4 cm), presence of lateral cervical LN metastasis, extrathyroidal invasion, and higher number of metastatic LN (≥10) were significant predictors for persistent disease. Multivariate analysis showed that extrathyroidal involvement, presence of lateral cervical LN metastasis, and older age at initial diagnosis (≥45 years) were independent predictors for persistent disease.

Despite the presence of LN involvement, most patients may become disease free with therapy. Patients with extrathyroidal invasion, lateral cervical LN involvement, and those at least 45 years old at initial diagnosis are more likely to have persistent disease. However, disease control can be achieved with close clinical follow-up and therapy.