Revisiting beta-2 microglobulin as a prognostic marker in diffuse large B-cell lymphoma.

BACKGROUND: Several clinical prognostic models for diffuse large B-cell lymphoma (DLBCL) have been proposed, including the most commonly used International Prognostic Index (IPI), the National Comprehensive Cancer Network IPI (NCCN-IPI), and models incorporating beta-2 microglobulin (ß2M). However, the role of ß2M in DLBCL patients is not fully understood. METHODS: We identified 6075 patients with newly diagnosed DLBCL treated with immunochemotherapy registered in the Danish Lymphoma Registry. RESULTS: A total of 3232 patients had data available to calculate risk scores from each of the nine considered risk models for DLBCL, including a model developed from our population. Three of four models with ß2M and NCCN-IPI performed better than the International Prognostic Indexes (IPI, age-adjusted IPI, and revised IPI). Five-year overall survival for high- and low-risk patients were 43.6% and 86.4% for IPI and 34.9% and 96.2% for NCCN-IPI. In univariate analysis, higher levels of ß2M were associated with inferior survival, higher tumor burden (advanced clinical stage and bulky disease), previous malignancy and increased age, and creatinine levels. Furthermore, we developed a model (ß2M-NCCN-IPI) by adding ß2M to NCCN-IPI (c-index 0.708) with improved discriminatory ability compared to NCCN-IPI (c-index 0.698, p < 0.05) and 5-year OS of 33.1%, 56.2%, 82.4%, and 96.4% in the high, high-intermediate, low-intermediate and low-risk group, respectively. CONCLUSION: International Prognostic Indices, except for NCCN-IPI, fail to accurately discriminate risk groups in the rituximab era. ß2M, a readily available marker, could improve the discriminatory performance of NCCN-IPI and should be re-evaluated in the development setting of future models for DLBCL.

Outcome of limited-stage peripheral T-Cell lymphoma after CHOP(-like) therapy: A population based study of 239 patients from the Nordic lymphoma epidemiology group.

Peripheral T-Cell Lymphomas (PTCLs) are rare, aggressive lymphomas with poor outcomes, but limited-stage disease is infrequent and not well-described. This study reports outcomes and prognostic factors in limited-stage nodal PTCLs in a binational population-based setting. Patients were identified from the Danish and Swedish lymphoma registries. Adults diagnosed with limited-stage nodal PTCL (stage I-II) and treated with CHOP(-like) therapy ±radiotherapy between 2000 and 2014 were included. Medical records were reviewed by local investigators. A total of 239 patients with a median age of 62 years were included; 67% received 6-8 cycles of CHOP(-like) therapy and 22% received 3-4 cycles, of which 59% also received radiotherapy. Autologous stem cell transplant consolidation was administered to 16% of all patients. Median follow-up was 127 months with 5-years overall survival (OS) of 58% (95% CI: 53-65) and progression-free survival (PFS) of 53% (95% CI: 47-59). In multivariable analysis, age ≥ 60 years and B-symptoms were unfavorable and ALK+ anaplastic large cell T-Cell lymphoma was favorable for survival outcomes. There was no difference in treatment-specific outcome (3-4 cycles vs. 6-8 cycles of CHOP(-like) ± radiotherapy). Low-risk patients (age < 60 without B-symptoms) had a 5-year OS of 77% (95% CI 67-89%). In the present study of limited-stage nodal PTCL, survival after curative intent chemotherapy +/- radiotherapy was inferior to that of limited-stage diffuse large B-cell lymphoma, but a subgroup of young patients without B-symptoms had very good outcomes. Treatment outcomes after 3-4 cycles versus 6-8 cycles of CHOP(-like) therapy were comparable.