A cutaneous lymphoma international prognostic index (CLIPi) for mycosis fungoides and Sezary syndrome

Abstract

Background: There is no prognostic index for primary cutaneous T-cell lymphomas such as mycosis fungoides (MF) and Sezary syndrome (SS).

Method: Two prognostic indices were developed for early (IA-IIA) and late stage (IIB-IVB) disease based on multivariate data from 1502 patients. End-points included overall survival (OS) and progression free survival (PFS). External validation included 1221 patients.

Findings: Significant adverse prognostic factors at diagnosis consisted of male gender, age >60, plaques, folliculotropic disease and stage N1/Nx for early stage, and male gender, age >60, stages B1/B2, N2/3 and visceral involvement for late stage disease. Using these variables we constructed two separate models each defined using 3 distinct groups for early and late stage patients: 0-1 (low risk), 2 (intermediate risk), and 3-5 factors (high risk). 10 year OS in the early stage model was 90.3% (low), 76.2% (intermediate) and 48.9% (high) and for the late stage model 53.2% (low), 19.8% (intermediate) and 15.0% (high). For the validation set significant differences in OS and PFS in early stage patients (both p<0.001) were also noted. In late stage patients, only OS differed between the groups (p=0.002).

Interpretation: This proposed cutaneous lymphoma prognostic index provides a model for prediction of OS in early and late stage MF/SS enabling rational therapeutic choices and patient stratification in clinical trials.

Keywords: Cutaneous lymphoma; Mycosis fungoides; Prognostic index; Sezary syndrome.