Is transoral robotic surgery useful as a salvage technique in head and neck cancers: a systematic review and meta analysis.

Background: Residual, recurrent, and second primary head and neck cancers are on the rise. This is largely driven by a younger age at diagnosis and increasingly targeted chemoradiotherapy options. Salvage surgery remains the only curative intent option in this cohort of patients. With transoral robotic surgery (TORS), achieving good oncological and functional outcomes in primary cancer cohorts, there remains a paucity of synthesized evidence on treating residual, recurrent, or second primary disease in previously irradiated fields.

Methods: Conducted in accordance with the JBI's methodology for systematic reviews of effectiveness, three databases were searched including PubMed, Embase, and Scopus. This study represents the largest systematic review till date finding 679 studies and including 15 after screening and critical appraisal. A meta-analysis of proportions and comparison was conducted using Freeman-Tukey arcsine transformation statistical method and the Mantel-Haenszel statistical method, respectively.

Results: Data from 515 patients was analyzed with a median follow-up time up to 47 months and a mean hospital stay of 8.5 days. Two-year overall survival (OS) rate and disease-free survival (DFS) rate were 73.8% and 56.1%, respectively. Compared to primary head and neck cancer, risk ratios for OS and DFS were 0.35 (95% CI, 0.18-0.67) and 0.44 (95% CI, 0.22-0.88). Weighted mean for tracheostomy decannulation and nasogastric dependence was 9.7 and 12.8 days, respectively, with long term tracheostomy dependence in 0%-11.5% of patients. Positive surgical margins were obtained in 19.4% with a risk ratio of 1.08 (95% CI, 0.66-1.75) when compared to primary head and neck cancer. Recurrence rate was 36% (95% CI, 24-48.9). Pooled complication rate was 32.3% with 92% of complications being classed as Clavien Dindo grade 2 or 3.

Conclusion: TORS is an emerging technique for salvage in recurrent, residual, and second primary head and neck cancers in previously irradiated fields. Survival outcomes are encouraging with decreased morbidity and mortality rates when compared to traditional open surgical techniques. Future studies need to mandate collection of swallowing data as a key tool to evaluate functional outcomes, deploy longer follow-up times, and address confounding factors including HPV status and prior adjuvant therapy.