CD5 Negative Mantle Cell Lymphoma: Clinicopathologic Correlations and Outcome in 58 Cases

• Published in: Blood 2016-12, Vol.128 (22), p.2964-2964
• Main Authors: Saksena, Annapurna, Miao, Yuan, Lin, Pei, Wang, Michael, Yin, C. Cameron, Li, Jingyi, Medeiros, L. Jeffrey, Li, Shaoying
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V128.22.2964.2964

Introduction: Mantle cell lymphoma (MCL) is a B-cell neoplasm that has a characteristic immunophenotype of being positive for CD5, B-cell antigens and cyclin D1. A small subset of cases of MCL can be negative for CD5, approximately 5% in the literature. The clinicopathologic features and prognosis of patients with CD5-negative MCL are poorly characterized. Here, we study a group of patients with CD5- MCL and compare them with a group patients with CD5+ MCL. Methods: From a total of 270 cases of MCL accessioned from 2004-2015, 58 CD5- cases (study group) and 212 CD5+ cases (control group) were identified. All cases of MCL were positive for cyclin D1 by immunohistochemistry and, in most patients, CCND1-IGH was shown FISH. Cases negative for CD5 were assessed by flow cytometry and/or immunohistochemistry. Fisher exact test was utilized to analyze differences between the CD5- and CD5+ groups. Patient survival was analyzed using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate Cox proportional hazards model analyses for OS and PFS were performed (SPSS 22 software). A P-value of less than 0.05 was considered statistically significant. Results: The CD5- group included 39 men and 19 women with a median age of 66 years (range, 36- 88 years) at time of diagnosis. The CD5- and CD5+ groups shared overlapping clinicopathological features, but CD5- cases showed a lower percentage of men (P=0.006) than CD5+ cases. Treatment information was available for 50 patients. Twenty-nine (58%) patients were treated initially with R-Hyper CVAD therapy (rituximab, fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with high dose methotrexate and cytarabine). Seventeen (34%) patients were treated initially with less aggressive therapy: 7 with R-CHOP; 8 had other rituximab-based chemotherapy regimens; 2 received rituximab as a single agent. Four patients (8%) were observed without therapy. After induction, 34 patients achieved complete remission (CR), 5 patients achieved partial remission (PR), 6 patients showed no response (NR) or progressive disease (PD), and 5 patients lost follow-up. Ten patients also underwent stem cell transplantation (SCT): 5 patients received allogeneic SCT, the other 5 autologous SCT. With a median follow-up of 45.7 months (range, 2.0-174.3 months), 13 of 56 (23.2%) patients died, 43 of 56 (76.8%) patients were alive at last follow-up, and the rest of 2 patients lost follow up. The i