Outcome of papillary thyroid microcarcinoma: Study of 1,990 cases

Abstract

The present study examines the requirement of prophylactic neck node dissection in papillary thyroid microcarcinoma (PTMC) patients by analyzing high-risk factors of neck lymph node metastasis in PTMC. The clinical pathological data was a review of 1,990 patients diagnosed between January 2013 and January 2014. The data included information on patient gender, age, tumor size, multifocal, tumor pathological staging, bilateral thyroid cancer, the subtypes, <i>BRAF</i>^V600E mutation, human telomerase reverse transcriptase (<i>hTERT</i>), extrathyroidal invasion and neck lymph node metastasis. The univariate analysis (χ² test) showed that a number of factors were significantly associated with neck lymph node metastasis in PTMC (P<0.05): Male gender, aged <45 years, extrathyroidal invasion, bilateral thyroid cancer, various subtypes (package type, follicular variant, diffuse sclerosing variant, eosinophils, tall cell and column variant), <i>BRAF</i>^V600E mutation-positive, <i>hTERT</i> mutation-positive, pt3/4 and multifocality. The multivariate analysis (regression binary logistic) showed that the male gender, <45 years, tumor size >5 mm, extrathyroidal invasion, bilateral thyroid tumors, multifocality, <i>BRAF</i>^V600E mutation-positive, <i>hTERT</i> mutation-positive and pt3/4 are associated with the neck lymph node metastasis in PTMC (P<0.05). These paired analysis results show that the subtypes of PTMC with tumor size >5 mm is more common than the specific types of PTMC in which the tumor is ≤5 mm in neck lymph node metastasis. The neck lymph node metastasis incidence of the >45 years age group patients without high-risk factors in PTMC is 8.13 and 6.80%, respectively. In conclusion, PTMC patients with high-risk factors only are recommended to undergo a prophylactic lymph node dissection.