Prognostic factors in Sézary syndrome: a multivariate analysis of clinical, haematological and immunological features

Sézary syndrome (SS) prognostic factors are not well defined because of the rarity of this disease. The specific goal of this prospective study was to assess by multivariate analysis the predictive value with respect to survival of a series of clinical, haematological and immunological parameters taken at SS diagnosis.

A cohort of 62 SS patients diagnosed and followed since 1975 was examined, and 51 were included in the multivariate analysis model.

The median survival time was 31 months (range: 1 month-15.7+ years), and the five-year survival rate 33.5%. The following variables were found by univariate analysis to be associated with a poor prognosis at the time of SS diagnosis: previous history of mycosis fungoides (P = 0.013), high number of circulating leukocytes (P = 0.001), Sézary cells (SC) (P < 0.001) and CD4+ cells (P < 0.001), presence of large circulating SC (P < 0.001), above normal range LDH serum levels (P = 0.015), presence of PAS-positive inclusions in the cytoplasm of circulating SC (P < 0.001), high CD4/CD8 ratio (P = 0.004) and a CD7 negative circulating SC phenotype (P < 0.001). Among them, the stepwise multivariate analysis selected as adverse independent prognostic factors: PAS-positive cytoplasmic inclusions (P = 0.001), CD7 negative phenotype (P = 0.018) and presence of large circulating SC (P = 0.045).

Two low-/high-risk groups have been singled out on the basis of the risk index. Patients with no or one adverse prognostic feature(s) (risk index < or = 1; n = 31) share a slow disease course and a relatively favorable prognosis (five-year survival: 58%); on the other hand, patients with 2 or 3 adverse prognostic feature (risk index > 1; n = 20) are characterized by an aggressive disease course not modifiable by traditional therapies (five-year survival: 5%).