Management of advanced parotid cancer. A systematic review.
BACKGROUND
Primary 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.


OBJECTIVE
The purpose of this paper is to analyse the important prognostic indicators for this cancer.


METHODS
A 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.


RESULTS
T 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%.


CONCLUSIONS
High-grade advanced parotid cancers are associated with a poor survival. Adjuvant radiotherapy is indicated in these tumours and this improves survival.
Jeannon
J-P
JP
Department of Head & Neck Oncology, Guy's, King's & St Thomas' Cancer Centre, Guy's & St Thomas' NHS Foundation Trust, 3rd Floor, Thomas Guy House, London SE1 9RT, UK. jpjeannon@doctors.org.uk
Calman
F
F
Gleeson
M
M
McGurk
M
M
Morgan
P
P
O'Connell
M
M
Odell
E
E
Simo
R
R
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D006801:Humans; D009367:Neoplasm Staging; D010307:Parotid Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D016019:Survival Analysis; D016896:Treatment Outcome