Does adjuvant alpha-interferon improve outcome when combined with total skin irradiation for mycosis fungoides?

BACKGROUND: Patients with mycosis fungoides (MF) experience frequent disease recurrences following total skin electron irradiation (TSEI) and may benefit from adjuvant therapy. OBJECTIVES: To review the McGill experience with adjuvant alpha-interferon (IFN) in the treatment of MF. METHODS: From 1990 to 2000, 50 patients with MF were treated with TSEI: 31 with TSEI alone and 19 with TSEI + IFN. Median TSEI dose was 35 Gy. In the TSEI + IFN group, IFN was given subcutaneously at 3 x 10(6) units three times per week starting 2 weeks prior to start of TSEI, continued concurrently with the radiation and for an additional 12 months following TSEI. The TSEI alone group included 16 men and 15 women with a median age of 61 years (range 31-84). The TSEI + IFN group included 14 men and five women with a median age of 51 years (range 24-83). Clinical stage was IA, IB, IIA, IIB, III and IVA in 2, 9, 4, 8, 1 and 7 patients of the TSEI group and 0, 3, 3, 7, 4 and 2 patients of the TSEI + IFN group. RESULTS: Median follow up for living patients was 70 months. All patients responded to treatment. Complete response (CR) rate was 65% following TSEI and 58% following TSEI + IFN (P = 0.6). Median overall survival (OS) was 61 months following TSEI and 38 months following TSEI + IFN (P = 0.4). Acute grade II-III dermatitis was seen in all patients. Fever, chills or myalgia were seen in 32% of patients treated with TSEI + IFN. CONCLUSIONS: Concurrent IFN and TSEI is feasible, with acceptable toxicity. Even when controlling for disease stage, the addition of IFN did not appear to increase CR rate, disease-free survival or OS.