Predictive effect of central lymph node intensity on lateral lymph node metastasis for papillary thyroid carcinoma

ABSTRACT

Objective:

To investigate the risk factors and predictive effect of lateral cervical lymph node metastasis of papillary thyroid carcinoma (PTC) by applying the concept of central lymph node metastasis intensity.

This study retrospectively analyzed integrated clinic data of 106 cases with PTC undergoing treatment of cervical lymph node dissection in Department of Thyroid and Breast Surgery of the Affiliated Hospital of Inner Mongolia Medical University from Dec. 2009 to Jan. 2014. Based on whether lateral cervical lymph nodes had metastasis, patents were classified into lymph node metastasis positive group ( n=75 cases) , lymph node metastasis negative group ( n=31 cases) . This study explored metastasis-associated risk factors of age, gender, triiodothyronine (T3) , thyroxine (T4) , free triiodothyronine (FT3) , free thyroxine (FT4) , thyroid stimulating hormone (TSH) , thyroglobulin antibody (TGAb) , thyroid peroxidase antibody (TPOAb) , whether combined with Hashimoto’s disease, tumor location, infringing the membrane, mulifocality, tumor glands distribution, tumor diameter, number of central lymph node metastases, central lymph node metastasis ratio, and analyzed the effects of central lymph node metastasis intensity on lateral cervical lymph node metastasis. SPSS 21.0 software was used for data analysis, the metering data of normal distribution was expressed as ± s, and t test was used for comparison between groups. Count data was expressed as a rate (composition ratio) , and comparisons between groups were performed by χ2 test or Fisher exact probability method.

Univariate analysis found that whether combined with Hashimoto’s disease ( P=0.087) , tumor location ( P=0.249) , tumor glands distribution ( P=0.219) and tumor diameter ( P=0.224) had no correlation with lateral cervical lymph node metastasis, which showed no statistical significant differences ( P>0.05) . Infringing the membrane ( P=0.030) , mulifocality ( P=0.031) , number of central lymph node metastases ( P=0.022) and central lymph node metastasis ratio ( P=0.001) had correlation with lateral cervical lymph node metastasis, which showed statistical significant differences ( P<0.05) . The number of central lymph node metastases and the increase of central lymph node metastasis ratio had positive correlation with the occurrence of lateral cervical lymph node metastasis; when the number of central lymph node metastases was ≥4 or (and) the central lymph node metastasis ratio was ≥20%, the incidence of lateral cervical lymph node metastases increased significantly, and the difference was statistically significant ( P<0.05) .

Infringing the membrane and mulifocality are risk factors for lateral cervical lymph node metastasis. When central lymph node metastasis intensity number of metastases ≥4 or (and) metastasis ratio ≥20%, lateral cervical lymph node dissection is recommended.