Topical nitrogen mustard in the management of mycosis fungoides: update of the Stanford experience.

OBJECTIVE: To evaluate and update the response and survival outcomes and toxic effects in patients treated with topical nitrogen mustard (mechlorethamine hydrochloride) as primary therapy.
DESIGN: A single-center, retrospective cohort analysis.
SETTING: Academic referral center for cutaneous lymphoma. PATIENTS: A total of 203 patients with mycosis fungoides (clinical stages I-III) treated with topical nitrogen mustard as initial therapy. MAIN OUTCOME MEASURES: Long-term actuarial survival, freedom-from-relapse, and freedom-from-progression results as calculated by the Kaplan-Meier method.
RESULTS: The overall response rate for the 203 patients was 83%, with a complete response rate of 50%. The median time to achieve complete response was 12 months (T1, 10 months; T2, 19 months), and the median time to relapse was 12 months. The duration of complete response increased with longer maintenance therapy; however, after completion of therapy, the response duration or relapse rate was similar regardless of maintenance regimen. Patients with T1 disease had better response and survival outcomes than those with T2 disease, with overall and complete response rates in T1 of 93% and 65%, respectively, and in T2, 72% and 34%, respectively. A similar clinical response was seen for patients with stage IIA vs IB. Sixty-eight percent of 203 patients received only topical nitrogen mustard therapy throughout their follow-up course, including most of the patients who achieved an initial complete response. The clinical response to topical nitrogen mustard as salvage therapy was similar to initial response rates. The efficacy results were similar in patients treated with aqueous vs ointment preparations. Freedom-from-progression rates in T1 disease (no progression to higher T classification or worse clinical stage) at 5 and 10 years were 92% and 85%, respectively, and in T2, 83% at 5 and 10 years. Fewer than 10% of patients experienced contact hypersensitivity reactions when topical nitrogen mustard was used as an ointment preparation. Only 8 patients (4%) developed secondary cutaneous malignancy, none attributable to topical nitrogen mustard monotherapy. Pediatric patients experienced no significant toxic effects with topical nitrogen mustard therapy.
CONCLUSIONS: Topical nitrogen mustard remains an effective primary initial or salvage therapy in mycosis fungoides for patients with T1 and T2 disease. Long-term follow-up results confirm its safety.