Background and Design: There are no large studies evaluating patients with erythrodermic mycosis fungoides and Sezary syndrome to determine the important prognostic factors that may influence survival. This is important since new treatment modalities have been proposed as superior to existing primary therapies. We performed a retrospective cohort study of 106 patients with erythrodermic mycosis fungoides and Sezary syndrome, followed up in the Stanford (Calf) Mycosis Fungoides Clinic, to define the important prognostic factors in this group. Results: Patients younger than 65 years have a more favorable survival profile than those 65 years or older (P<.005). Longer duration of symptoms before diagnosis (greater than or equal to 10 years) tends to be associated with more favorable prognosis (P=.055). Lymph node stage is significantly correlated with survival; patients with overall stage III disease have more favorable prognosis than those with stage IV disease (P<.001). Patients with circulating Sezary cells in their blood have a significantly worse prognosis than those without (P<.005). Patient sex or race had no significant effect on overall survival outcome. Three distinct prognostic groups were identified, ''favorable,'' ''intermediate,'' and ''unfavorable,'' according to the number of unfavorable prognostic factors (P<.005). The median survival in each group is 10.2, 3.7, and 1.5 years, respectively. Conclusions: In patients with erythrodermic mycosis fungoides and Sezary syndrome, the important prognostic factors are patient age at presentation, the overall stage, and peripheral blood involvement. Survival varies widely, depending on these variables. These prognostic factors should be evaluated when analyzing survival and/or treatment efficacy data of these patients.
