Incidence and prognostic significance of extranodal extension in isolated nodal recurrence of oral squamous cell carcinoma.

[Display omitted] • ENE in regional recurrence (rENE) is frequently present in OSCC neck recurrence. • Patients with advanced nodal history (N2/N3, ENE+, RT+) are at high risk of rENE. • Recurrent LN >1.5 cm is also closely related to rENE. • Extent of rENE in recurrent neck is significantly severe than in initial neck. • Individualized salvage treatment based on the presence of rENE should be recommended. Extranodal extension (ENE) is a crucial prognostic factor of oral squamous cell carcinoma (OSCC). However, the role of ENE in regional recurrence (rENE) remains unclear. The purpose of our study is to assess the salvage outcome according to the presence of rENE in oral cancer patients with isolated nodal recurrence. Oral cancer patients diagnosed with isolated nodal recurrence at the National Taiwan University Hospital between January 2010 and December 2015 were reviewed. All patients were classified into two groups: with and without rENE. The treatment included salvage neck dissection (ND) ± metronomic chemotherapy, salvage ND and radiation (RT)/concurrent chemoradiation (CCRT), Salvage RT/CCRT alone, metronomic chemotherapy, or supportive care. We analyzed 198 patients, 156 with rENE and 42 without rENE. rENE presented more frequently in patients with initial ENE+ (OR = 3.17, p = 0.04), prior RT+ (OR = 2.96, p = 0.02), initial N2/N3 (OR = 2.76, p = 0.01), and recurrent LN size >1.5 cm (OR = 2.33, p = 0.03). The extent of rENE were also significantly different in these patients. The 2-year disease-free survival for patients with and without rENE were 15.7% and 31.7%, respectively (p = 0.002). The 2-year overall survival for patients with and without rENE were 19.6% and 43.9%, respectively (p = 0.004). For patients without rENE, those received salvage ND had better survival outcome (p < 0.001). By contrast, for patients with rENE, those received salvage RT/CCRT had better survival outcome (p < 0.001). The rENE is frequently present (78.79%) in OSCC patients with isolated nodal recurrence. Individualized treatment modalities based on the presence of rENE should be recommended to achieve better salvage outcomes. [ABSTRACT FROM AUTHOR]