A retrospective study of the risk factors and the prognosis in patients with papillary thyroid carcinoma depending on the number of lymph node metastasis.

To retrospectively analyze the risk factors and the prognosis according to the number of lymph node metastases (LNMs) in different neck compartments in papillary thyroid carcinoma (PTC) patients. In total, 962 patients with PTC were enrolled in this study. According to the methods of the 2015 American Thyroid Association, the treatment response of the patients was divided into a good prognosis and a poor prognosis. First, their clinical characteristics were summarized. Then, according to whether they had LNMs and the number of LNMs in different neck compartments, their risk factors and their prognosis were analyzed. Male sex, younger (< 45 years), extrathyroid extension (ETE), T1 staging and higher stimulated thyroglobulin (sTg) levels were the risk factors for LNM. The cutoff for a poor prognosis of the number of LNMs was > 4. Male sex, younger age, higher sTg levels and ETE were correlated with LNM > 4. Furthermore, the cutoffs for a poor prognosis of central lymph node metastasis (CLNM), lateral lymph node metastasis (LLNM) and CLNM + LLNM were > 6, > 1 and > 5, respectively. Younger age and ETE were strongly correlated with CLNM > 6. Male sex, younger age, higher sTg levels and ETE were correlated with LLNM > 1. Younger age, ETE and higher sTg levels were correlated with CLNM + LLNM > 5. Further analysis revealed a positive correlation between CLNM and LLNM. We should pay more attention to LNMs in PTC patients who are male, are of a younger age, have ETE, T1 staging and have higher sTg levels. The neck regional LNMs should be correctly evaluated to guide the surgical options for the neck LNMs in PTC. When the number of LNMs in different neck compartments has exceeded the cutoff value, they can be considered as predictors of the outcome of 131I treatment.