Background: Salvage total laryngectomy is indicated for locally advanced, recurrent laryngeal squamous cell carcinoma after undergoing initial organ preservation therapy. Elective neck dissection (END) with salvage laryngectomy remains controversial due to variability in outcomes with regards to occult nodal metastasis rates, survival, and postoperative complications. To further understand the role of END, we performed a systematic review and meta-analysis examining the occult nodal metastasis rate and postoperative complications following END for treatment of the clinical N0 neck in the salvage setting.
Methods: A PubMed search was conducted using the following Boolean operators: neck dissection OR nodal dissection AND salvage laryngectomy. Search was filtered for English language without limit on years searched. Additional sources were found by reviewing bibliographies of pertinent articles (2 of 17 articles). A systematic review and meta-analysis of the literature was performed using the PRISMA recommendations. Variables assessed included occult nodal metastasis, subsite/T stage of recurrence, regional recurrence, disease free survival, overall survival, and postoperative complications. For meta-analyses, data were pooled using random effects models due to heterogeneity for both occult nodal disease and post-operative complication measures.
Results: The initial search identified 120 articles, of which 17 met inclusion criteria. One study was from 1999 and all others ranged from 2005 through present. A total of 994 patients were identified: 830 patients underwent END and 164 patients were observed. Of the patients that underwent END, 30% were supraglottic, 61% were glottic, 8% were transglottic, and 1% were subglottic. Subsite information was missing for 228 patients (6 of 17 studies), while recurrent T (rT) stage data was absent for 379 patients (11 of 17 studies). Based on meta-analyses, the rate of occult metastasis in patients undergoing END was 14% (CI 95%=11-17%, p<.01). In subsite-specific analyses, occult nodal metastasis rates were 24% for supraglottic, 9% for glottic, 17% for transglottic, and 6% for subglottic tumors. Additionally, occult nodal metastasis was higher in rT3/4 tumors (21%) compared to rT1/2 tumors (10%). Review of these studies demonstrated regional recurrence within the END group from 0-8%, with no statistically significant survival difference reported between END and observation groups. However, when patients were stratified based on recurrent T stage, survival benefit was found in one study of rT3/4 patients undergoing END. In our meta-analysis, the relative risk of postoperative complications with END compared to observation was 1.62 (CI 95%=.87-3.03, p=.13). Complications included fistula, wound infection/dehiscence, chyle leak, hematoma, revision procedure, flap failure, and medical complications.
Conclusions: Outcomes following END in cN0 salvage laryngectomy patients are highly heterogeneous in the literature. Prior studies are compromised by heterogeneity in the analyzed patient cohort with variable proportions of supraglottic versus glottic/transglottic cohorts. Our meta-analysis reveals an overall occult nodal metastasis rate of 14%, with higher rates of occult nodes in supraglottic and transglottic subsites as well as T3/4 recurrent tumors. These data suggest strongly considering END in supraglottic/transglottic subsites and all T3/T4 recurrent tumors in the salvage setting. However, multidisciplinary tumor board review is critical in the decision making of each patient undergoing salvage therapy.