The characteristics and risk factors of central compartment lymph node metastasis in cN0 papillary thyroid carcinoma coexistent with Hashimoto's thyroiditis.

BACKGROUND

Currently, there are few studies on the characteristics of lymph node metastasis in the central region in patients with preoperative negative lymph node (cN0) papillary thyroid carcinoma (PTC) coexistent with Hashimoto's thyroiditis (HT). There is still a significant controversy on whether to perform prophylactic central compartment lymph node dissection for T1/T2 cN0 PTC. Therefore, we aimed to investigate the characteristics and risk factors of central compartment lymph node metastasis in cN0 PTC (T1 or T2 stage) coexists with HT.

METHODS

From Jun. 2015 to Apr. 2019, the clinicopathological data of 354 patients with stage T1/T2 cN0 PTC admitted to the thyroid tumor surgery of Inner Mongolia People's Hospital were analyzed retrospectively. All patients underwent central compartment lymph node dissection. According to the results of the postoperative pathological examination, the patients were divided into two groups: PTC group (n=236) and PTC coexistent with the HT group (n=118).

RESULTS

The proportion of PTC patients with HT was 33.33% (118/354) in T1/T2 cN0 PTC patients; most of them were women. The levels of serum thyrotropin, antithyroglobulin antibody, and thyroid peroxidase antibody in PTC coexistent with HT group are higher than those in the PTC group (P<0.05). The number of lymphadenectomies in PTC coexistent with HT group was more than that in PTC alone group (P<0.05). Univariate analysis showed that antithyroglobulin antibody positive, tumor diameter >1 cm, and multifocal cancer in T1/T2 stage cN0 PTC coexistent with HT group were all correlated with lymph node metastasis in the central region (P<0.05). Logistic regression analysis showed that tumor diameter >1 cm, and multifocal cancer were the risk factors of central compartment lymph node metastasis in patients with T1/T2 stage cN0 PTC coexistent with HT (P<0.05).

CONCLUSIONS

HT is not a relevant factor of central lymph node metastasis in T1/T2 cN0 PTC; regardless of the presence or absence of HT, tumor diameter >1 cm and multifocal cancer are risk factors for central lymph node metastasis in patients with T1/T2 cN0 PTC. Therefore, preventive lymph node dissection in the central region should be conducted actively during the operation.