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.

Should we use nomograms for risk predictions in diffuse large B cell lymphoma patients? A systematic review.

Models based on risk stratification are increasingly reported for Diffuse large B cell lymphoma (DLBCL). Due to a rising interest in nomograms for cancer patients, we aimed to review and critically appraise prognostic models based on nomograms in DLBCL patients. A literature search in PubMed/Embase identified 59 articles that proposed prognostic models for DLBCL by combining parameters of interest (e.g., clinical, laboratory, immunohistochemical, and genetic) between January 2000 and 2024. Of them, 40 studies proposed different gene expression signatures and incorporated them into nomogram-based prognostic models. Although most studies assessed discrimination and calibration when developing the model, many lacked external validation. Current nomogram-based models for DLBCL are mainly developed from publicly available databases, lack external validation, and have no applicability in clinical practice. However, they may be helpful in individual patient counseling, although careful considerations should be made regarding model development due to possible limitations when choosing nomograms for prognostication.

Prognostic indices in diffuse large B-cell lymphoma: a population-based comparison and validation study of multiple models.

Currently, the International Prognostic Index (IPI) is the most used and reported model for prognostication in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). IPI-like variations have been proposed, but only a few have been validated in different populations (e.g., revised IPI (R-IPI), National Comprehensive Cancer Network IPI (NCCN-IPI)). We aimed to validate and compare different IPI-like variations to identify the model with the highest predictive accuracy for survival in newly diagnosed DLBCL patients. We included 5126 DLBCL patients treated with immunochemotherapy with available data required by 13 different prognostic models. All models could predict survival, but NCCN-IPI consistently provided high levels of accuracy. Moreover, we found similar 5-year overall survivals in the high-risk group (33.4%) compared to the original validation study of NCCN-IPI. Additionally, only one model incorporating albumin performed similarly well but did not outperform NCCN-IPI regarding discrimination (c-index 0.693). Poor fit, discrimination, and calibration were observed in models with only three risk groups and without age as a risk factor. In this extensive retrospective registry-based study comparing 13 prognostic models, we suggest that NCCN-IPI should be reported as the reference model along with IPI in newly diagnosed DLBCL patients until more accurate validated prognostic models for DLBCL become available.

Bone marrow biopsy can be omitted in the diagnostic workup of CNS lymphoma of DLBCL origin: a population-based retrospective study in the PET-CT era.

Currently, bone marrow (BM) biopsy (BMB) is recommended in the initial staging of patients with the presumed primary central nervous system (CNS) lymphoma (PCNSL). However, the added value of BMB in the era of positron emission tomography (PET-CT) has been challenged in other lymphoma subtypes. We analyzed BM findings in patients with biopsy-proven CNS lymphoma and a negative PET-CT scan for disease outside CNS. A comprehensive Danish population-based registry search was performed to identify all patients with CNS lymphoma of diffuse large B cell lymphoma (DLBCL) histology with available BMB results and staging PET-CT without systemic lymphoma. A total of 300 patients fulfilled the inclusion criteria. Of them, 16% had a previous history of lymphoma, while 84% were diagnosed with PCNSL. None of the patients had DLBCL in the BM. A minority (8.3%) had discordant BMB findings, mainly low-grade histologies that did not influence treatment choice in any case. In conclusion, the risk of overlooking concordant BM infiltration in patients with CNS lymphoma of DLBCL histology and negative PET-CT scan is negligible. As we did not find any patient with DLBCL in the BMB, our results suggest that BMB can be safely omitted in the diagnostic workup in patients with CNS lymphoma and a negative PET-CT.

Extramedullary Hematopoiesis Visualized on FDG-PET/CT in a Patient with Beta-Thalassemia.

Beta-thalassemia is an inherited blood disorder caused by reduced or absent synthesis of the beta chains of hemoglobin, resulting in decreased hemoglobin production. Symptoms depend on the type of beta-thalassemia ranging from no symptoms to severe illness. Ineffective erythropoiesis leads to a sequence of events responsible for bone marrow expansion, anemia, hemolysis, splenomegaly, increased iron absorption, and sometimes extramedullary hematopoiesis (EMH). We report an interesting case with EMH visualized on FDG-PET/CT and where FDG-PET/CT has also found the focus of a severe infection in a patient with beta-thalassemia.

Distal chromosome 1q aberrations and initial response to ibrutinib in central nervous system relapsed mantle cell lymphoma.

Relapse involving the central nervous system (CNS) is an infrequent event in the progression of mantle cell lymphoma (MCL) with an incidence of approximately four percent. We report four cases of MCL with CNS relapse. In three of the four patients a large chromosomal copy-number alteration (CNA) of 1q was demonstrated together with TP53 mutation/deletion. These patients experienced brief response to ibrutinib, whereas a fourth patient harboring mutated ATM demonstrated a long-term effect to ibrutinib and no CNA. Although it is unclear whether chromosome 1q CNA contribute to specific phenotypes these reports may be of value as such lesions are uncommon features of MCL.

Prognostic models in primary central nervous system lymphoma patients: A systematic review.

Over the last decade, several prognostic models have been proposed for primary central nervous system lymphoma (PCNSL), but consensus on the optimal model for these patients is absent or lacking. This study aims to review available prognostic models for PCNSL and discuss their prognostic features. A comprehensive literature search performed in Pubmed/Embase identified ten studies with a variable number of analysed patients (range 32-3453), which proposed 12 prognostic models. Age and performance status were the most important prognostic factors in PCNSL and an integral part of the majority of the proposed models. However, there is no universally accepted prognostic model for PCNSL owning to a number of limitations such as a small number of patients, limited samples obtained for genetic analysis, retrospective nature of studies, single centre studies, and lack of validation. Future multicentre studies are necessary to determine the optimal prognostic model for PCNSL by combining different prognostic markers of significance.

[Primary central nervous system lymphomas].

In this review, we discuss primary central nervous system lymphomas: a rare type of tumours confined to the central nervous system. The disease is associated with a poor prognosis, which, however, generally has seen steady improvement over the last four decades, particularly in the younger population. Modern surgical techniques are reserved for diagnosis and has no place in the treatment, which mainly relies on high-dose polychemotherapy treatment regimes with methotrexate as the backbone.