Prognostic factors in primary cutaneous anaplastic large cell lymphoma: characterization of clinical subset with worse outcome.

OBJECTIVES: To identify prognostic factors in primary cutaneous anaplastic large cell lymphoma (pcALCL), focusing on extensive limb disease (ELD), defined as initial presentation or progression to multiple skin tumors in 1 limb or contiguous body regions, and to study gene expression profiles of patients with pcALCL.

DESIGN: Retrospective cohort study.

SETTING: The Stanford Comprehensive Cancer Center and dermatology ambulatory clinics.

PATIENTS: A total of 48 patients with pcALCL evaluated from 1990 through 2005.

MAIN OUTCOME MEASURES: Hazard ratios (HRs) for prognostic factors for overall survival (OS) and disease-specific survival (DSS) and risk factors for progression to extracutaneous disease were identified using Cox regression. Gene expression profiles of 9 typical pcALCL and 3 ELD samples were investigated using complementary DNA microarrays.

RESULTS: Univariate analysis demonstrated age, ELD, and progression to extracutaneous disease as significant prognostic factors for OS, whereas ELD and progression to extracutaneous disease were significant for DSS. In multivariate analysis, age (HR, 1.83; 95% confidence interval [CI], 1.02-3.26) and progression to extracutaneous disease (HR, 6.42; 95% CI, 1.39-29.68) remained significant for OS, whereas ELD (HR, 29.31; 95% CI, 1.72-500.82) and progression to extracutaneous disease (HR, 13.12; 95% CI, 1.03-167.96) remained independent prognostic factors for DSS. Presentation with T3 disease was a risk factor for progression to extracutaneous disease (HR, 10.20; 95% CI, 1.84-56.72). Microarray data revealed that patients with ELD and typical pcALCL formed distinct clusters.

CONCLUSIONS: Patients with ELD have a more aggressive course associated with a differential gene expression profile. More aggressive treatments may be indicated for patients with ELD and those whose disease progresses to extracutaneous disease because they have poorer outcomes.