title: Adenoid cystic carcinoma of head and neck: clinical predictors of outcome from a Canadian centre.
abstract: OBJECTIVE
  Adenoid cystic carcinoma (acc) is often treated with surgery, with or without adjuvant radiation therapy (rt). We evaluated disease characteristics, treatments, and potentially prognostic variables in patients with acc.
  
  
  METHODS
  Our retrospective analysis considered consecutive cases of acc presenting at a tertiary care hospital between 2000 and 2014. Factors predictive of overall survival (os) and disease-free survival (dfs) were identified by univariate analysis.
  
  
  RESULTS
  The 60 patients analyzed had a mean age of 58 years (range: 22-88 years), with a 2:1 female:male ratio. Tumour locations included the major salivary glands (40% parotid, 17% submandibular and sublingual), the oro-nasopharyngeal cavity (27%), and other locations (16%). Of the 60 patients, 35 (58%) received surgery with adjuvant rt; 12 (20%), rt only; 13 (22%), surgery only. Of 18 patients (30%) who experienced a recurrence within 5 years, 3 (5%) developed local recurrence only, and the remaining 15 (25%), distant metastasis. The 5-year os and dfs were 64.5% [95% confidence interval (ci): 45.9% to 78.1%] and 46.2% (95% ci: 29.7% to 61.2%) respectively. In patients without recurrence, 5-year os was 77% (95% ci: 52.8% to 89.9%), and in patients with recurrence, it was 42.7% (95% ci: 15.8% to 67.6%). Patients treated with rt only had a 5-year os of 9.2%. Predictors of 5-year dfs were TNM stage, T stage, nodal status, treatment received, and margin status; age, nodal status, treatment received, and margin status predicted 5-year os.
  
  
  CONCLUSIONS
  Despite surgery and rt, one third of patients with acc experience distant recurrence. Patients whose tumours are not amenable to surgery have a poor prognosis, indicating a need for alternative approaches to improve outcomes.
authors.affiliation: Department of Medical Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, AB;
authors.forename: J J
authors.initials: JJ
authors.lastname: Ko
authors.affiliation: Department of Biostatistics, Public Health Innovation and Decision Support Population and Public Health, Alberta Health Services, AB;
authors.forename: J E
authors.initials: JE
authors.lastname: Siever
authors.affiliation: Department of Medical Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, AB;
authors.forename: D
authors.initials: D
authors.lastname: Hao
authors.affiliation: Department of Pathology, Foothills Medical Centre, University of Calgary, Calgary, AB;
authors.forename: R
authors.initials: R
authors.lastname: Simpson
authors.affiliation: Department of Oncology, University of Calgary, Calgary, AB.
authors.forename: H Y
authors.initials: HY
authors.lastname: Lau
keywords: Adenoid cystic carcinoma; head-and-neck cancer; prognostic factors