Sentinel node biopsy versus elective neck dissection in early-stage oral cancer: a systematic review

Purpose: To provide a summary of the evidence on the comparative effectiveness of two surgical treatment strategies, sentinel node biopsy (SNB) and elective neck dissection (END), in patients with T1–T2 oral cancer and clinically negative (cN0) neck, in terms of overall survival (OS), disease-free survival (DFS) and neck recurrence rates (NRRs). Methods: A systematic review was performed by including studies published up to April 2019. Meta-analysis was performed to compare NRRs between SNB and END. A narrative summary of the results was generated for OS, DFS and morbidity outcomes. The certainty of evidence was assessed according to the GRADE methodology. Results: No randomized studies were retrieved. Five observational studies were included in the comparative effectiveness analysis and four observational studies were included in the comparative morbidity analysis. The pooled risk ratio showed no differences in NRRs between SNB and END (10.5% vs 11.6%; pooled RR 1.09; 95% CI 0.67–1.76). No differences in OS or DFS between the two treatments were found. SNB appears to be associated with a lower rate of postoperative complications and lower shoulder dysfunction than END. Conversely, the results of the quality of life (QoL) questionnaires are not sufficient to advocate a particular strategy. Conclusion: Our review highlights the lack of well conducted and randomized studies comparing SNB to END, leading to poor clinical evidence. Although our findings suggest no significant differences in OS, DFS and NRR between the two strategies, the certainty of our evidence is too low to make it useful for clinical decision making.