Folliculotropism Does Not Affect Overall Survival in Mycosis Fungoides: Results from a Single-Center Cohort and Meta-Analysis

Abstract

Background: Folliculotropic mycosis fungoides (FMF) is a distinct subtype of mycosis fungoides (MF) with unique clinicopathological features. The medical literature suggests that FMF has a more aggressive course and worse survival than classic MF. Previous studies do not use standardized treatment, and no studies have reported an association between treatment response and overall survival (OS). Objective: To compare OS for MF, FMF, and Sézary syndrome (SS) patients. Methods: Data were collected retrospectively from 218 patients (171 MF, 15 SS, 32 FMF) treated in a single academic center between 1970 and 2016. Results: Negative predictors of OS were age (OR = 1.07), male sex (OR = 1.63), and stage IIB, III, and IV (OR = 4.10, 5.42, and 7.54, respectively, vs. stage IA). Lack of initial PUVA response was strongly associated with negative OS (OR = 3.08). Kaplan-Meier analysis of age-, sex-, and stage-matched MF and FMF patients found similar OS between the 2 groups. The 5-year OS was 91% for FMF and 74% for MF. Meta-analysis of current data and 2 published studies where survival of FMF patients was compared to MF did not reveal statistically significant differences between these 2 diseases. Conclusions: When patients were matched for age, sex, and disease stage, folliculotropism did not affect OS in MF.