LBA 07 - A Phase II Trial of Induction Paclitaxel Followed by Concurrent Paclitaxel and Radiation Therapy for Cutaneous Angiosarcoma

Purpose/Objective(s): Cutaneous angiosarcoma is a rare, aggressive malignancy with high rates of local recurrence and early distant metastasis despite multimodality therapy. Taxane-based chemotherapy has demonstrated activity in advanced angiosarcoma, but its role in localized disease has not been prospectively evaluated. We conducted a phase II trial to evaluate induction paclitaxel followed by concurrent paclitaxel and radiation therapy for localized cutaneous angiosarcoma.

Materials/Methods: This single-arm phase II study enrolled adults with localized, histologically confirmed cutaneous angiosarcoma and ECOG performance status =1. Patients received 6 weeks of induction paclitaxel (80 mg/m² weekly), followed by concurrent weekly paclitaxel (80 mg/m²) with external beam radiation (50–50.4 Gy in 25–28 fractions). Surgery was performed when feasible after chemoradiotherapy; radiation boost and/or hyperthermia were permitted at physician discretion. The primary endpoint was 2-year progression-free survival (PFS). Secondary endpoints included overall survival (OS), pathologic complete response (pCR), and grade =3 acute and late treatment-related toxicity (CTCAE v5.0). Kaplan-Meier methods were used to estimate time-to-event outcomes.

Results: Between September 2019 and December 2025, 20 patients were enrolled and 19 were evaluable. Median age was 71 years (range, 57–81); 8 (42%) had head and neck primaries and 11 (58%) breast/chest wall primaries. All patients received induction paclitaxel, and 19 (100%) completed concurrent paclitaxel and radiotherapy; 2 (11%) required RT dose reductions, and 11 (58%) required chemotherapy breaks. Surgical resection was performed in 18 (95%) patients. At a median follow-up of 25 months, estimated 2-year PFS, local control, and OS were 82.5%, 82.5%, and 87.4%, respectively. Among patients who underwent surgery, a pathologic complete response was observed in 10 (56%). Grade =3 acute and late treatment-related toxicities occurred in 11 (58%) and 6 (32%) of patients, respectively, most commonly radiation dermatitis. There were no treatment-related deaths.

Conclusion: Induction paclitaxel followed by concurrent paclitaxel and radiotherapy demonstrated promising disease control with acceptable toxicity in localized cutaneous angiosarcoma. These findings compare favorably with historical outcomes and support further investigation of taxane-based chemoradiotherapy in this high-risk population.