Clinical risk factors for central lymph node metastasis in papillary thyroid carcinoma: a systematic review and meta-analysis

BackgroundProphylactic central lymph node dissection (CLND) in clinically node-negative patients remains controversial, and predictive factors for central lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC) are not well defined. Herein, we conducted a systematic review to quantify the clinicopathologic factors predictive for CLNM in patients with PTC. MethodsA systematic search of electronic databases (PubMed, Embase, Cochrane CENTRAL, Scopus and Wanfang Database) for studies published until July 2014 was performed. Cohort, case-control studies and randomized controlled trials that examined clinical risk factors of CLNM were included. ResultsTwenty-five studies (4 prospective and 21 retrospective studies) involving 7,719 patients met final inclusion criteria. From the pooled analyses, male gender (OR 193, 95% CI 140 to 264), tumour multifocality (OR 193, 95% CI 162 to 230), tumour size >05cm (OR 348, 95% CI 224 to 541), capsular invasion (OR 191, 95% CI 136 to 267), extrathyroidal extension (OR 242, 95% CI 158 to 371), lymphovascular invasion (OR 1329, 95% CI 561 to 3148) and lateral lymph node metastasis (OR 1433, 95% CI 534 to 3850) were significantly associated with increased risk of CLNM, while age >45years (OR 065, 95% CI 051 to 083) and lymphocytic thyroiditis (OR 070, 95% CI 053 to 092) resulted in decreased risk of CLNM. Bilaterality and tumour location were not significantly associated with CLNM development (all P>005). ConclusionsOur analysis identified several clinicopathologic factors associated with CLNM. These findings may guide the necessity and extent of prophylactic CLND and ultimately improve the outcomes of patients with PTC.