Outcome analysis of 215 patients with parotid gland tumors: a retrospective cohort analysis

Background: To identify prognostic factors in patients with parotid gland carcinomas who were treated at the Princess Margaret Hospital. Methods: Clinical outcome of two hundred fifteen patients with malignancies of the parotid gland was evaluated over a 16-year period. Results: Two-hundred-fifteen patients with adenoid cystic carcinoma (n = 20), adenocarcinoma (n = 19), acinic cell carcinoma (n = 62), basal cell adenocarcinoma (n = 7), carcinoma-ex-pleomorphic adenoma (n = 18), mucoepidermoid carcinoma (n = 70) and salivary duct carcinoma (n = 19) have been included. The 5- and 10-year overall and disease-free survivals were 80.62 %/69.48 % and 74.37 %/62.42 %, respectively. Multivariable analysis showed that age greater than 60 years, advanced pN classification, histopathological grade and the presence of lymphovascular invasion significantly worsened overall and disease-free survival. Univariable analysis revealed periparotid lymph node involvement was associated with decreased overall (p < 0.0001) and disease-free survival (p < 0.0001). Conclusions: In addition to age, pN classification, histopathological grade, perineural invasion, and lymphovascular involvement, periparotid lymph node metastasis appears to be an important prognosticator in parotid gland malignancy.