Background Topical nitrogen mustard is a chemotherapeutic agent used in treatment of mycosis fungoides (MF).
Objective To evaluate the response and side effects in patients with MF and parapsoriasis treated with topical nitrogen mustard.
Methods A retrospective study of treatment response in 116 patients diagnosed with MF and 71 patients with parapsoriasis and treated with topical nitrogen mustard from 1991 to 2009.
Results Overall response rate and complete response (CR) rate was 91.4% and 53.4% in patients with MF and 90.1% and 40.8% in patients with parapsoriasis, respectively. Relapse following CR was observed in 67.7% in patients with MF and 62.1% in patients with parapsoriasis. Freedom-from-relapse was higher in patients with T1-T2 than in T3 disease (P < 0.01). Progressive disease (PD) occurred in 25.0% and 26.8% in patients with MF and parapsoriasis, respectively. Progression-free survival was similar in patients with T1-T2 compared with T3 (P = 0.79) and T4 disease (P = 0.22) and lower in patients with parapsoriasis with <10% than >10% skin involvement (P = 0.05).
Conclusion The present study confirms that topical nitrogen mustard is a safe and effective therapy. The treatment response in patients with parapsoriasis was not statistically different from the response in patients with MF. This supports, that parapsoriasis is not a distinct entity, but an early stage of MF. Nitrogen mustard should therefore still be considered as an important treatment modality in patients with early stages (parapsoriasis) and later stages of MF either as monotherapy or in combination with other topical or systemic therapies.