- A retrospective review suggests that adjuvant radiotherapy (ART) may not improve disease control in patients with parotid gland acinic cell carcinoma (ACC) whose only histopathologic risk factor is a close (≤1 mm) but negative margin.
Why this matters
- The benefits of ART in this patient population are unclear.
- 9% of patients experienced recurrence (7% distant metastases; 2% local recurrence).
- 5-year OS was 93% and 5-year DFS was 89%.
- Absence of high-risk factors (advanced T category, nodal disease, lymphovascular or perineural invasion, high-grade histology, or positive margins) was associated with improved DFS (HR, 0.08; 95% CI, 0.01-0.71 in univariate analysis).
- In patients without high-risk factors, margins ≤1 mm were associated with higher likelihood of ART (56% vs 7%; difference, 49%; 95% CI, 16%-82%).
- In the 18 patients with margins ≤1 mm without other high-risk factors, only 1 patient who had received ART experienced a recurrence at 136 months postsurgery.
- 45 patients with parotid gland ACC were analyzed for locoregional control, recurrence patterns, survival, and associated factors.
- Funding: None disclosed.
- Retrospective study.
- Small patient sample size.
- Lack of multivariate analysis.