Prognostic factors in primary cutaneous B-cell lymphoma: the Italian Study Group for Cutaneous Lymphomas.

Purpose: Primary cutaneous B-cell lymphomas (PCBCLs) are a distinct group of primary cutaneous lymphomas with few and conflicting data on their prognostic factors.
Patients and Methods: The study group included 467 patients with PCBCL who were referred, treated, and observed in 11 Italian centers (the Italian Study Group for Cutaneous Lymphomas) during a 24-year period (1980 to 2003). All of the patients were reclassified according to the WHO-European Organisation for Research and Treatment of Cancer (EORTC) classification.
Results: Follicle center lymphoma (FCL) accounted for 56.7% of occurrences, followed by marginal-zone B-cell lymphoma (MZL; 31.4%); diffuse large B-cell lymphoma (DLBCL), leg type, was reported in 10.9% of patients. Radiotherapy was the first-line treatment in 52.5% of patients and chemotherapy was the first-line treatment in 24.8% of patients. The complete response rate was 91.9% and the relapse rate was 46.7%. The 5- and 10-year overall survival (OS) rates were 94% and 85%, respectively. Compared with FCL/MZL, DLBCL, leg type, was characterized by statistically significant lower complete response rates, higher incidence of multiple cutaneous relapses and extracutaneous spreading, shorter time to progression, and shorter OS rates. The only variable with independent prognostic significance on the OS was the clinicopathologic diagnosis according to the WHO-EORTC classification (DLBCL, leg-type, showed a significantly worse prognosis v FCL and MZL; P < .001), whereas the only variable with independent prognostic significance on disease-free survival was the presence of a single cutaneous lesion (P = .001).
Conclusion: Our study identifies a possible PCBCL subclassification and the extent of cutaneous involvement as the two most relevant prognostic factors in PCBCL. These data can be considered reasonably as the clinical background for an appropriate management strategy.