Confirmation of the prognostic value of the EORTC/WHO classification of primary cutaneous B-cell lymphoma in the United States: The Stanford University experience

Abstract

8028 Background: Primary cutaneous B cell lymphoma (CBCL) represent distinct clinicopathologic entities with superior prognosis compared to their nodal counterparts. In the new WHO/EORTC Classification of Cutaneous Lymphomas (WHOc), CBCL are classified as either Marginal Zone (MZ), Follicle center lymphoma (FC) or diffuse large cell-leg type (DLBCL leg-type). WHOc combined previous FL and DLBCL into the category of FC. Only DLBCL leg-type was considered to be aggressive and thus separately categorized. In order to confirm the utility of the WHOc categories, we reclassified our cases. Methods: Records of 154 CBCL patients (pts) managed at Stanford University were reviewed. A diagnosis of CBCL was made based on H&E evaluation, immunohistochemistry including CD20 staining, along with a negative systemic staging evaluation. All pts were reclassified according to the WHO/EORTC classification of CBCL. Overall Survival (OS), disease specific survival (DSS) and freedom from progression (FFP) were analyzed according to the method of Kaplan and Meier. Prognostic factors were evaluated by multivariate regression model and included initial therapy, histology, LDH, stage, IPI, extent of disease and anatomic location. Results: 154 cases were reclassified as follows: 87 FC, 58 MZ, and 9 DLBCL leg-type. The median follow-up was 46 months. The 5 year OS and DSS were 86 and 95% respectively. For the MZ and FC subtypes the % 10 year OS/DSS was: 93/100, and 86/97 respectively. For DLBCL leg-type the % 5 year OS/DSS was 17/33 respectively. There were 22 deaths, seven of which were disease specific (4 DLBCL-leg type and 3 were FC). FFP was unaffected by the type of therapy given (chemotherapy or skin-directed). Conclusions: Our series is the largest single center experience in CBCL. We confirm the utility of the WHOc in distinguishing categories with differing prognosis. The indolent histologies have an excellent outcome and can be managed with local skin-directed therapy. The outcome of pt with DLBCL leg-type is significantly worse than the FC or MZ types and warrants a more aggressive approach in management. No significant financial relationships to disclose.