title: The DAHANCA 6 randomized trial: Effect of 6 vs 5 weekly fractions of radiotherapy in patients with glottic squamous cell carcinoma.
abstract: OBJECTIVE
  The DAHANCA 6 trial evaluated tumor response and morbidity after moderate accelerated radiotherapy compared to conventional fractionated radiotherapy in patients treated for glottic squamous cell carcinoma (SCC). Further, the failure pattern and incidence of new primary tumors were explored.
  
  
  METHODS
  Six hundred and ninety-four patients with non-metastatic glottic SCC were randomized between six or five weekly fractions (fx/w) of radiotherapy to the same total dose. The median treatment time was 38 and 46days, respectively. The primary endpoint was loco-regional failure.
  
  
  RESULTS
  Median follow-up time was 14.5years. Of the 177 failures, 167 involved T-site. The cumulative incidence of loco-regional failure (LRF) was 21.6% in the 6fx/w group and 29.3% in the 5fx/w group and the corresponding hazard rate (HR) of LRF was 0.72 (CI: 0.53-0.97, p=0.04). The effect of acceleration on LRF was especially evident in well differentiated tumors (HR=0.42 (CI: 0.23-0.75) and in T1-2 tumors (HR=0.60 (CI: 0.41-0.89)). The HR of laryngectomy was 0.72 (CI: 0.50-1.04) in the 6fx/w group compared to the 5fx/w group. The hazards of disease-specific death, event-free survival, and overall survival were comparable between the two groups. Significantly more patients experienced severe acute mucositis in the 6fx/w group but the incidence of late morbidity was comparable between the groups. New primary tumors occurred in 22.5% of the patients.
  
  
  CONCLUSIONS
  Moderate accelerated radiotherapy significantly improved loco-regional control in patients with glottic SCC.
authors.affiliation: Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark. Electronic address: nina@oncology.au.dk.
authors.forename: Nina M
authors.initials: NM
authors.lastname: Lyhne
authors.affiliation: Department of Oncology, Aarhus University Hospital, Denmark.
authors.forename: Hanne
authors.initials: H
authors.lastname: Primdahl
authors.affiliation: Department of Oncology, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Claus A
authors.initials: CA
authors.lastname: Kristensen
authors.affiliation: Department of Oncology, Herlev Hospital, Copenhagen, Denmark.
authors.forename: Elo
authors.initials: E
authors.lastname: Andersen
authors.affiliation: Department of Oncology, Odense University Hospital, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Johansen
authors.affiliation: Department of Oncology, Aalborg University Hospital, Denmark.
authors.forename: Lisbeth J
authors.initials: LJ
authors.lastname: Andersen
authors.affiliation: Norwegian Radium Hospital, Oslo, Norway.
authors.forename: Jan
authors.initials: J
authors.lastname: Evensen
authors.affiliation: Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark.
authors.forename: Hanna R
authors.initials: HR
authors.lastname: Mortensen
authors.affiliation: Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Overgaard
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D005260:Female; D005931:Glottis; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D007822:Laryngeal Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D052016:Mucositis / Q000209:etiology; D011832:Radiation Injuries / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects; D000077195:Squamous Cell Carcinoma of Head and Neck
keywords: Accelerated radiotherapy; Glottic cancer; Head and neck squamous cell carcinoma