title: Risk factors for lymph node metastasis in papillary thyroid microcarcinoma: Older patients with fewer lymph node metastases.
abstract: BACKGROUND
  Lymph node metastasis (LNM) is an important consideration in treatment strategy selection for papillary thyroid microcarcinoma (PTMC). The aim of this study was to investigate the risk factors for LNM and high-volume LNM (hvLNM, >5 metastatic lymph nodes).
  
  
  METHODS
  A consecutive series of 1226 PTMC (947 female, 279 male) patients was reviewed. All patients underwent at least central neck dissection. Clinical-pathological features were assessed. All patients were allocated into Group A (≤39 yrs), Group B (40-59 yrs), or Group C (≥60 yrs) for risk factor analysis.
  
  
  RESULTS
  Among all patients, 438 LNM and 73 hvLNM were detected. Older patients had significantly fewer LNM (A: 51.45% of 346, B: 30.15% of 786, and C: 24.47% of 94) and fewer hvLNM (A: 11.85%, B: 3.94%, and C: 1.06%). Male, multifocality, and tumor diameter >0.5 cm were also correlated with LNM and hvLNM. In multivariate analysis, older patients had lower risk of LNM (odds ratio [OR] 0.389 in B, 0.305 in C), and chronic thyroiditis was protective factor for LNM (OR 0.524). Male (OR 1.651), tumor diameter >0.5 cm (OR 1.850), and multifocality (OR 1.928) were risk factors for LNM. Similarly, older patients had lower risk of hvLNM (OR 0.313 in B, OR 0.085 in C). Male (OR 2.590), tumor diameter >0.5 cm (OR 2.180), and multifocality (OR 1.980) were also risk factors for hvLNM.
  
  
  CONCLUSIONS
  Older PTMC patients may have fewer LNM and lower risk of hvLNM. For patients ≥60 years old, dynamic observation may be an option for clinical management.
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Sun
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Surgery Department, First Affiliate Hospital of Hebei North University, Zhangjiakou, He Bei, China.
authors.forename: F
authors.initials: F
authors.lastname: Liang
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China.
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.affiliation: General Surgery Department, Second Hospital of Shanxi Medical University, Taiyuan, Shan Xi, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Shang
authors.affiliation: Institute of Basic Medical Sciences, Chinese Academy of Medical Science, School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.affiliation: General Surgery Department, Peking Union Medical College Hospital, Beijing, China. Electronic address: li.xiaoyi@263.net.
authors.forename: X
authors.initials: X
authors.lastname: Li
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002291:Carcinoma, Papillary / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000473:pathology*
keywords: Age; High volume metastasis; Lymph node metastasis; Papillary thyroid microcarcinoma; Risk factor