Prognostic significance of positive surgical margins for scalp angiosarcoma

Background: Scalp angiosarcomas (AS) are aggressive soft tissue sarcomas that present with outcomes different from other AS of the head and neck region. Due to the rarity of the disease, limited data on the clinical outcome of scalp AS are available. In particular, the prognostic significance of surgical margins remains controversial and the impact of margin status on survival has not been documented. Methods: We retrospectively reviewed 41 scalp AS patients, including 30 patients with localized disease and 11 patients with initial distant metastasis, treated in our institution between 1997 and 2017. Survival was determined by Kaplan-Meier analysis. In the 30 patients without distant metastasis (localized disease), univariate and multivariate analysis using the Cox proportional hazards model were used to determine clinicopathologic characteristics associated with recurrence free survival (RFS), locoregional control (LRC), and overall survival (OS). Results: Totally 41 patients diagnosed with scalp AS were identified, including 30 patients with localized disease and 11 patients with initial distant metastasis on diagnosis. Overall, the me-dian follow-up period was 19.3 (range 0.3-128.5) months. The median survival time was 16.6 (range 0.3-144.3) months and the 5-year OS (95% Confidence Interval (CI)) rate was 22% (12% 42%). In the 30 patients with localized disease, univariate analysis showed that positive margins, either lateral-side or deep-side, were significant prognostic factors for RFS, LRC, and OS (p < 0.05). On multivariate analysis, positive margins emerged as adverse prognostic factors for RFS (Hazard Ratio (HR) 4.29, 95% CI, 1.71-10.75, p = 0.002), LRC (HR 6.35, 95% CI, 2.19 18.37, p = 0.001), and OS (HR 4.73, 95% CI, 1.71-13.07, p = 0.003). Conclusion: Scalp AS is associated with high local recurrence rates and poor survival outcomes. Positive surgical margins are adverse prognostic factors for survival. Copyright (C) 2020, Formosan Medical Association. Published by Elsevier Taiwan LLC.