Acinic cell carcinoma of the salivary gland in the adult and paediatric population: a survival analysis

Background Acinic cell carcinoma (AcCC) is a rare malignant neoplasm of the salivary glands and generally considered to be a low-grade tumour. Surgical treatment is often curative, but a more aggressive high-grade variant has been associated with poorer survival and propensity for distant metastasis. No standard treatment guidelines exist and the approach to treatment is varied in the published series. The aim of this study is to present the experience of three major hospitals in Sydney, Australia, in treating AcCC of the salivary gland, with a focus on clinico-pathological features of disease and their associations with survival outcomes. Methods Adult and paediatric cases of AcCC of the salivary gland during the time period 1979-2018 were retrospectively included. Demographic, clinico-pathological, treatment and survival outcome data were extracted. Survival analysis was undertaken to assess the effect of clinical and pathological variables on overall and disease-free survival. Results Thirty-two cases were reviewed (29 adult and three paediatric). Thirty tumours (93.8%) were parotid gland primary tumours. Mean overall and disease-free survival was 17.0 +/- 0.7 and 16.0 +/- 0.9 years, respectively. Features associated with poorer survival were cT staging >1, presence of preoperative clinical facial nerve deficit and local recurrence. Positive margins were associated with recurrence. Conclusion These data suggest that disease-free and overall survival in AcCC of the salivary gland is excellent with surgery as the first-line treatment. Poor survival outcomes are uncommon and may be associated with locally advanced disease in the presence of other well-established high-risk features.

Automated summary

Acinic cell carcinoma (AcCC) is a rare malignant neoplasm of the salivary glands, with surgery as the first-line treatment showing excellent survival outcomes. The clinico-pathological features and treatment methods are associated with survival results, with certain high-risk factors linked to poor survival outcomes.