Management of advanced parotid cancer. A systematic review

BackgroundPrimary adenocarcinomas of the parotid gland are rare and account for less than 5% of all head and neck malignant neoplasms. There is considerable variation in biological behaviour within this group; low-grade tumours exhibit slow growth rates with minimal or no local invasion. High-grade tumours, however, show a high incidence of local recurrence and distant metastasis.AimThe purpose of this paper is to analyse the important prognostic indicators for this cancer.MethodsA systematic review was performed involving 19 published studies from 1987 to 2005 which included 4631 patients. T stage, grade of tumour, N stage and adjuvant radiotherapy on overall (5 year) survival were analysed as prognostic indicators.ResultsT stage (p = 0.041, hazard ratio 1.8 (confidence interval 1.2–2.9)), N stage (p = 0.05, hazard ratio 1.1 (0.2–1.8)), and high-grade (p = 0.001, hazard ratio 2.1 (1.5–2.7)) were associated with a significantly worse survival. The effect of adjuvant radiotherapy was to improve overall survival: p = 0.002, hazard ratio 2.9 (1.5–4.7). The mean 5 year survival for advanced high-grade parotid cancer was 35%.ConclusionHigh-grade advanced parotid cancers are associated with a poor survival. Adjuvant radiotherapy is indicated in these tumours and this improves survival.