Objective: The present study conducted a meta-analysis to forecast the risk factors associated with level-VII lymph node metastases in case of thyroid neoplasms, intending to assist in determining the requirement for level-VII lymph node lymphadenectomy during the surgery.
Methods: Electronic databases, PubMed, Embase, the Cochrane Library, CNKI, Wanfang Data, VIP, and CBM electronic databases were searched for studies focused on level-VII lymph node metastases in thyroid neoplasms, published up to April 2021. Stata 13.1 software was used for analyses.
Results: The literature search identified a total of 997 studies. Among these, 8 studies, involving 1813 patients, were included in the present case. All these studies were case-control studies. Results for meta-analysis showed that male (OR = 1.340, 95% CI: 1.018-1.764, P = .037), age < 45 years (OR = 4.178, 95% CI: 1.601-10.908, P = .003), tumor size ≥ 2.0 cm (OR = 1.960, 95% CI: 1.079-3.562, P = .027), extrathyroidal extension (OR = 2.037, 95% CI: 1.578-2.630, P < .001), distant metastasis (OR = 2.775, 95% CI: 2.005-3.840, P < .001), central lymph node metastasis (OR = 3.500, 95% CI: 1.127-10.874, P = .03), contralateral cervicolateral metastasis (OR = 2.119, 95% CI: 1.514-2.965, P < .001), and bilateral nodal metastasis (OR = 4.651, 95% CI: 2.697-8.020, P < .001) acted as risk factors for level-VII lymph node metastases. In addition to this, sensitivity analyses and bias test showed that the results of meta-analysis were reliable and stable and involved no publication bias.
Conclusion: In the present study, male gender, age < 45 years, tumor size ≥ 2.0 cm, extrathyroidal extension, distant metastasis, central lymph node metastasis, contralateral cervicolateral metastasis, and bilateral nodal metastasis were identified as risk factors for level-VII lymph node metastases in case of thyroid neoplasms.
Keywords: level-VII lymph node; meta-analysis; risk factors; thyroid neoplasms; upper mediastinal lymph node.