Lymph node metastasis from olfactory neuroblastoma at presentation and as disease relapse: A systematic review and proportion meta-analysis of prevalence data and variables influencing regional control

Background: Aim of this study is to investigate the prevalence of cervical nodal metastasis at presentation and as disease relapse in primary, treatment-naive olfactory neuroblastoma (ONB), and to review treatment modalities, risk factors for regional failure and survival outcomes according to nodal status. Methods: A systematic review and proportion meta-analysis were conducted following PRISMA guidelines based on PubMed, Web of Science, and Scopus. Results: Eighteen articles were examined. The pooled proportion of patients with nodal metastasis at presentation (11.5%) was comparable to that of cN0 patients not receiving elective neck treatment developing nodal metastasis during follow-up (12.3%). Of the latter, most were Kadish stage C tumors (85.5%). Conclusions: Cervical involvement is common both at presentation and during follow-up of cN0 ONB. The highest risk of developing late nodal metastasis is seen in cN0 patients with Kadish stage C tumors not receiving elective neck treatment. Elective cN0 neck treatment should be encouraged in selected patients to increase regional control.