title: Methylation of sodium iodide symporter promoter correlated with aggressiveness and metastasis in papillary thyroid carcinoma: a meta-analysis.
abstract: BACKGROUND
  Methylation of sodium iodide symporter promoter has been reported to increase the incidence of papillary thyroid carcinoma (PTC). In this meta-analysis stratified via methylation of sodium iodide symporter promoter, we evaluate the relationship between methylation of sodium iodide symporter promoter and PTC. The association between methylation with aggressiveness and metastasis potential of PTC is also discussed.
  
  
  METHODS
  We searched electronic databases for original articles and references of included studies both in English and Chinese from 1966 to 2014. Two reviewers selected the case-control study and extracted data from relevant literature independently.
  
  
  RESULTS
  Seven articles, including 360 cases and 268 controls, were involved in this meta-analysis. The prevalence of PTC in patients with methylated sodium iodide symporter promoter was significantly higher than those with non-methylated promoter (OR=7.36, 95% CI: 4.25-12.74, P<0.001). Stratified analysis showed that PTC patients with multiple lesions, capsule invasion and lymphatic metastasis had significantly higher rates of methylation (OR=2.22, 95% CI: 1.12-4.41, P=0.02; OR=2.14, 95% CI: 1.12-4.08, P=0.02; OR=3.56, 95% CI: 1.97-6.46, P<0.0001). But no relationship was found among the methylation of sodium iodide symporter and age, gender and size of tumor.
  
  
  CONCLUSIONS
  The methylation of sodium iodide symporter promoter is related with PTC and its aggressive and metastatic potential. Due to the limited sample size, more clinical researches should be taken in the future.
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China.
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Zhao
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China ; School of Medicine, Shandong University Jinan 250012, China.
authors.forename: Huan-Jun
authors.initials: HJ
authors.lastname: Wang
authors.affiliation: School of Medicine, Shandong University Jinan 250012, China.
authors.forename: Hai-Peng
authors.initials: HP
authors.lastname: Wang
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China.
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Yao
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Wu
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Shang
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Qilu Hospital of Shandong University Jinan 250012, China.
authors.forename: Huan-Gao
authors.initials: HG
authors.lastname: Zhu
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Qilu Hospital of Shandong University Jinan 250012, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Dong
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, Shandong Provincial Qianfoshan Hospital Jinan 250014, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Liao
keywords: Sodium iodide symporter; aggressiveness; metastasis; methylation; papillary thyroid carcinoma