Pattern of failure in 5001 patients treated for glottic squamous cell carcinoma with curative intent – A population based study from the DAHANCA group

Abstract Purpose To describe the pattern of failure in a national consecutive cohort of patients with glottic squamous cell carcinomas (SCC) treated with primary radiotherapy (RT) with curative intent over a 41-year period. Materials and methods All patients undergoing curative treatment for a glottic SCC diagnosed in Denmark between 1971 and 2011 were included and followed from the first contact with the oncology center to death or February 15, 2015. Results 5001 patients were identified of whom 98% had primary RT. The median follow-up was 9.1 years/5.7 years (patients alive/patients who died). Ten patients were lost to follow-up. In total 1511 failures were observed; of these 93%, 11% and 5% included T site, N site, and M site, respectively. For patients diagnosed in the 70s and the 00s, respectively, the five-year incidences were: local failure (32% vs 19%), loco-regional failure (34% vs 21%), laryngectomy (26% vs 10%), laryngectomy-free survival (48% vs 62%), disease-free survival (62% vs 68%), and overall survival (62% vs 68%). The five-year incidence of ultimate failure (13–16%) remained statistically unchanged. Conclusion From the 70s to the 00s a continually improving primary disease-control was observed with a concurrent decrease in the incidence of laryngectomy. The survival rate was significantly higher in the 00s compared to the previous three decades.