The value of squamous cell carcinoma antigen (SCCa) to determine the lymph nodal metastasis in cervical cancer: A meta-analysis and literature review

Background: The diagnostic power of CT or MRI on the lymph node status was limited. Supplement measurements were needed to assist the diagnosis of lymph node metastasis. The SCCa was reported to be close related to lymph node status. But currently the clinical value of serum SCCa measurement in lymph node status has not been clearly defined. This meta-analysis was to investigate this topic on a large scale. Method: Searching the Pubmed, Embase, Cochrane library, CNKI and Wanfang database for SCC-Ag/SCCA/SCC-antigen and cervical cancer/tumor/carcinoma/neoplasm published in any language from Jan 1 1990 to Aug 1 2017. QUADAS (quality assessment of diagnostic accuracy studies) was used to evaluate the quality of the articles. An eligible set of data should include true positive, true negative, false positive and false negative number. Every set of data was extracted and analyzed by STATA 14.0. The forest plot and bivariate boxplot were utilized to evaluate the heterogeneity. The funnel graph was used to test the publication bias. The SROC curve was draw via random effect model and HSROC model. Result: 17 sets of data and 3985 patients were included for the diagnostic meta-analysis. There was heterogeneity, which was partially from SCCa cut-off value. The pooled sensitivity was 0.70 and specificity was 0.63. AUC was 0.73. Eight articles provided the relative risk value of lymphatic metastasis when SCCa increased. The relative risk of lymph node metastasis increased ranging from 2.3–40 as with different SCCa cut off value. Conclusion: The diagnostic value of SCCa for lymph nodal metastasis was medium and it was strongly related to lymph node status. Thus SCCa could assist imaging tests to detect lymph node metastasis. Besides, it was correlated with para-aortic lymph node metastasis.