Long-term follow-up in 51 patients with mycosis fungoides and Sézary syndrome treated by interferon-alfa.

Although interferon-alfa (IFN-alpha) has proved effective in treating epidermotropic cutaneous T-cell lymphoma (ECTL), few studies have considered the follow-up of treated patients and whether complete remission was maintained. We studied 51 patients (one stage Ia, seven stage Ib, one stage IIa, 30 stage IIb, 11 stage III (Sézary syndrome) and one stage IV) who received low-dose IFN-alpha as monotherapy for ECTL (mean daily dose of IFN-alpha 2.7 x 106 units for 14.9 months), giving special consideration to the significance of My7 (CD13) antigen expression by epidermal basal cells in predicting the maintenance of complete remission. For a mean follow-up period of 43.4 months, the results showed 21 complete remissions, 13 partial remissions and 17 patients with stable or progressive disease. Twelve patients died during the follow-up (3-52 months). IFN-alpha led to an improved response in the early stages, with a greater number of complete remissions (P = 0.03) and partial remissions (P = 0.01). The mean time to complete remission was 4 months, regardless of clinical stage (P = 0.1). Of 21 patients in complete remission, 57% had a relapse within a mean period of 7.5 months. For patients maintained in complete remission, the mean period of response was 31 months. The length of complete remission was independent of clinical stage, and My7 antigen expression was not predictive of complete remission.