The DAHANCA 27 Phase II Study: Transoral Laser Microsurgery for T1aN0M0 Glottic Squamous Cell Carcinoma, a Comparison to Accelerated Radiotherapy.

[INTRODUCTION] Endoscopic surgery of T1a glottic squamous cell carcinoma (SCC) is believed to have advantages compared to radiotherapy (RT), including short duration, cost-effectiveness, repeatability, and RT reserved for second tumors/failures. The equality of tumor control probability after treatments is unresolved.

[METHODS] In the DAHANCA 27 phase II study, selected Danish patients suspected of T1a glottic SCC between 2012 and 2016 were offered one-step diagnostic and curatively intended transoral laser microsurgery (TLM). The 5-year outcome was compared to a 2003-2012 national cohort of T1a glottic SCC patients treated with accelerated RT (accRT).

[RESULTS] The TLM (n = 94) treatment included cordectomy type I (n = 44), II (n = 38), and III (n = 12). Failure was observed in 10/94 TLM and 36/534 accRT patients, resulting in 1 and 23 laryngectomies, respectively. The 5-year laryngectomy-free disease-specific survival was TLM 97.9% and accRT 94.6%, HR: 0.37 (0.09, 1.54).

[CONCLUSIONS] Primary TLM for selected T1a glottic SCC patients is an organ preserving treatment with high disease control comparable to accRT.