Prognostic significance of extranodal extension in cervical lymph node metastases of head and neck squamous cell carcinoma: A systematic review and meta-analysis with bibliometric overview.

OBJECTIVE

Extranodal extension (ENE) of cervical lymph node metastases is a key prognostic factor in head and neck squamous cell carcinoma (HNSCC). This systematic review and meta-analysis evaluated the survival impact of ENE in HNSCC and identified global research trends relevant to this research field through a complementary bibliometric analysis.

MATERIALS AND

METHODS

ScienceDirect, PubMed, and Scopus were systematically searched during 2000-2025. A systematic review and a meta-analysis were conducted in accordance with the PRISMA 2020 guidelines. A Scopus-based bibliometric analysis was conducted using the Biblioshiny package of R to identify and map the publication trends, influential authors, and major institutional contributions between 2010 and 2025.

RESULTS

Of the 839 retrieved records, 711 studies were screened, and 16 studies comprising approximately 3900 patients met all inclusion criteria. The bibliometric analysis of 120 Scopus-indexed publications demonstrated a marked increase in ENE-related research from 2015 onward, driven primarily by institutions in Australia, Taiwan, and South Korea. Keyword mapping indicated expanding intersections of ENE research with radiomics, prognostic modelling, and refinement of staging systems. Meta-analysis confirmed a significant association between ENE and adverse survival outcomes. Subgroup analyses showed consistently poor prognostic implications across both pathologic and radiologic ENE assessments.

CONCLUSION

ENE in cervical lymph node metastases is an independent and strong predictor of adverse survival in HNSCC. The increasing global attention to ENE highlights its crucial role in multidisciplinary oncologic management. Therefore, standardized pathological and imaging-based assessment of ENE is essential for developing superior prognostic models and optimizing future treatment planning strategies.