LAUSR

BACKGROUND Mycosis fungoides with large cell transformation (MF-LCT) is associated with an aggressive clinical course yet data comparing treatment outcomes in MF-LCT are sparse. OBJECTIVE To compare treatment outcomes and to determine disease prevalence and characteristics associated with survival in MF-LCT. METHODS A retrospective review of MF patients from 2012 to 2020 treated at Thomas Jefferson University was conducted. Patients with histopathological diagnosis of MF-LCT were included. Treatment outcomes were assessed by mean changes in mSWAT (modified Severity Weighted Assessment Tool) and stage. RESULTS Of 171 patients with MF, 23 (13.4%) had histological diagnosis of MF-LCT. The overall 5-year survival rate for MF-LCT was 74% and was not significantly associated with gender, age, or initial stage at the time of MF-LCT diagnosis. Brentuximab vedotin showed the greatest mean decrease in mSWAT (-20.53) and stage progression (Δstage: -0.4) in MF-LCT compared to oral bexarotene (ΔmSWAT: +4.51; Δstage: +0.27), skin directed therapy (SDT) (ΔmSWAT: -5.93; Δstage: -0.08), and chemotherapy (ΔmSWAT: +4.97; Δstage: +0.85). LIMITATIONS Single-center retrospective design, patients often on multiple treatment modalities. CONCLUSIONS We report superior treatment outcomes for brentuximab vedotin compared to oral bexarotene, SDT, and chemotherapy in MF-LCT in both early and advanced disease.