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

Abstract

Background: Prophylactic 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.

Methods: A 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.

Results: Twenty-five studies (4 prospective and 21 retrospective studies) involving 7,719 patients met final inclusion criteria. From the pooled analyses, male gender (OR 1.93, 95% CI 1.40 to 2.64), tumour multifocality (OR 1.93, 95% CI 1.62 to 2.30), tumour size >0.5 cm (OR 3.48, 95% CI 2.24 to 5.41), capsular invasion (OR 1.91, 95% CI 1.36 to 2.67), extrathyroidal extension (OR 2.42, 95% CI 1.58 to 3.71), lymphovascular invasion (OR 13.29, 95% CI 5.61 to 31.48) and lateral lymph node metastasis (OR 14.33, 95% CI 5.34 to 38.50) were significantly associated with increased risk of CLNM, while age >45 years (OR 0.65, 95% CI 0.51 to 0.83) and lymphocytic thyroiditis (OR 0.70, 95% CI 0.53 to 0.92) resulted in decreased risk of CLNM. Bilaterality and tumour location were not significantly associated with CLNM development (all P > 0.05).

Conclusions: Our 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.