The prognostic value of radiologic extranodal extension in nasopharyngeal carcinoma: Systematic review and meta-analysis

The prognostic value of radiologic extranodal extension (rENE) in nasopharyngeal carcinoma remains controversial. In this study, a meta-analysis was performed to assess the prognostic value of ungraded rENE and unambiguous advanced rENE.A literature search through PubMed, Cochrane Library, EMBASE and manual searches was conducted until May 2021. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of overall survival and distant metastasis-free survival were extracted and pooled.Nine eligible studies were published between 2012 and 2021. The pooled patient number was 7532 (range 61-1887). Seven studies were eligible for the analysis of ungraded rENE, while 3 studies were eligible for unambiguous advanced rENE. The results showed that ungraded rENE was associated with worse overall survival (HR 1.85, 95% CI 1.04-3.27) and significantly associated with worse distant metastasis-free survival (HR 2.07, 95% CI 1.36-3.13). On the other hand, unambiguous advanced rENE was significantly associated with worse overall survival (HR 2.62, 95% CI 2.12-3.25) and worse distant metastasis-free survival (HR 3.14, 95% CI 1.85-5.33).In nasopharyngeal carcinoma, both ungraded and unambiguous advanced rENE are significant prognosticators of overall survival and distant metastasis-free survival. More prospective studies are required to determine its role in risk stratification or clinical staging.