[Risk Factors for central lymph node metastasis in 1 988 papillary thyroid microcarcinoma patients]

Objective:To determine the risk factors that increase the neck central lymph node metastasis in papillary thyroid microcarcinoma(PTMC). Method:In this retrospective study,clinical and pathologic data were collected from patients who were first diagnosed as PTMC at the Xinjiang Medical University affiliated Tumor Hospital from January 2010 to March 2016. Chi-square test and multivariate logistic regression analysis were used to identify the risk factors of the neck central lymph node metastasis. Result:Of all 1988 patients,34.9% had the neck central lymph node metastasis. Age<45 years（P<0.05）,male（P<0.05),multifocality（P<0.05）,bilaterality（P<0.05）,tumor size >5 mm（P<0.05）,capsular invasion（P<0.05）or extrathyroidal extension（P<0.05）were significantly correlated with the neck central lymph node metastasis. Multivariate logistic regression analysis indicated that male, age <45 years, tumor size >5 mm,capsular invasion,extrathyroidal extension were independently correlated with the neck central lymph node metastasis. For patients with a solitary primary tumor, tumor location was independently correlated with the neck central lymph node metastasis.Unifocal tumor location in the lower third of the thyroid lobe was associated with the highest risk of the neck central lymph node metastasis(46.8%)(P<0.05).Multifocal tumor location was not associated with the neck central lymph node metastasis(P>0.05). Conclusion:More aggressive treatment or more frequent follow-up could be considered for patients with unfavorable features(male gender, age <45 years,tumor size >5 mm,capsular invasion,extrathyroidal extension,unifocal tumor location in the lower third of the thyroid lobe), as these patients may be at an increased risk for the neck central lymph node metastasis.