Age as a potential new prognostic indicator in primary cutaneous B-cell lymphoma (PCBCL).

Abstract

e19034 Background: PCBCL is a group of rare lymphoproliferative disorders, with an estimated annual incidence of 2.5 per 1,000,000 persons. Indolent subtypes include Primary Cutaneous Marginal Zone Lymphoma (PCMZL) and Primary Cutaneous Follicular Center Lymphoma (PCFCL). Primary Cutaneous Diffuse Large B-cell Lymphoma (PCDLBCL) is an aggressive subtype with a fatality rate of 50%. The Cutaneous Lymphoma International Prognostic Index (CLIPI) can risk-stratify indolent subtypes, but age is not considered. Here we present our single-institutional analysis of clinicopathologic features and outcomes of patients with PCBCL. Methods: This is a retrospective study of patients evaluated at Moffitt Cancer Center between 01/1990 and 12/2016. Patients were identified using our PCBCL database and diagnosis was verified by independent hematopathologists and dermatopathologists. Staging was determined by ISCL/EORTC criteria. Demographics, subtype, stage, disease course, and CLIPI scores were collected. Continuous and categorical values were tested using Kruskal-Wallis ANOVA method and Fisher’s Exact Test, respectively. Kaplan-Meier curves were produced to determine PFS. Results: We identified 37 patients who met diagnostic criteria for PCBCL (35% PCFCL, 40.5% PCMZL, 13.5% PCDLBCL, and 11% indolent, unspecified). Male:female ratio was 2.4:1. 51% of patients were ≥ 60 years old (yo), and 49% were < 60 yo. 54% had stage T1 disease, 27% T2, and 19% T3. Median PFS for patients <60 was 1.1 years, but was not reached for those ≥60. Mean follow-up time was 2.6 years for all patients. Log-rank test showed a statistically significant difference in PFS between the two age groups (p=0.01). PFS for stage of indolent subtypes showed marginal significance (p <0.06). CLIPI for indolent subtypes did not show a significant difference in PFS. Conclusions: We found that age is a highly statistically significant prognostic parameter in PCBCL, as patients ≥ 60 yo had a longer PFS compared to younger patients, even after adjusting for stage and CLIPI. These results are promising for age as a possible prognostic indicator for PCBCL, but validation is needed with a larger sample size.