Recommendations for Treatment in Folliculotropic Mycosis Fungoides: Report of the Dutch Cutaneous Lymphoma Group

Background: Folliculotropic mycosis fungoides (FMF) is an aggressive variant of mycosis fungoides (MF) and generally less responsive to standard skin-directed therapies (SDTs). Recent studies distinguished indolent (early-stage FMF) and more aggressive (advanced-stage FMF) subgroups. The optimal treatment for both subgroups remains to be defined.

Objectives: To evaluate initial treatment results in patients with early- and advanced-stage FMF.

Methods: A study was undertaken of 203 patients (84 early-stage, 102 advanced-stage, 17 extracutaneous FMF) included in the Dutch Cutaneous Lymphoma Registry between 1985 and 2014. Type and results of initial treatment were retrieved from the Dutch Registry. Main outcomes were complete remission (CR); sustained complete remission; partial remission (PR), > 50% improvement; and overall response (OR; CR + PR).

Results: Patients with early-stage FMF were treated with nonaggressive SDTs in 67 of 84 cases resulting, respectively, in CR and OR of 28% and 83% for monotherapy topical steroids, 0% and 83% for ultraviolet B (UVB), and 30% and 88% for psoralen plus ultraviolet A (PUVA). In patients with advanced-stage FMF these SDTs were less effective (combined CR and OR 10% and 52%, respectively). In patients with advanced-stage FMF local radiotherapy (CR 63%; OR 100%), total skin electron beam irradiation (CR 59%; OR 100%) and PUVA combined with local radiotherapy (CR 5%, OR 75%) were most effective.

Conclusions: The results of the present study demonstrate that not all patients with FMF should be treated aggressively. Patients with early-stage FMF may benefit very well from standard SDTs also used in early-stage classic MF and have an excellent prognosis.