Risk factors for poor treatment outcome and central nervous system relapse in diffuse large B-cell lymphoma with bone marrow involvement

Biological Features and Prognostic Impact of Bone Marrow Infiltration in Patients with Diffuse Large B-Cell Lymphoma

The biology and clinical impact of bone marrow (BM) infiltration in patients with diffuse large B-cell lymphoma (DLBCL) remains unclear in the rituximab era. We retrospectively analyzed 232 patients diagnosed with DLBCL at our center between 1999 and 2014. Concordant-presence of large cells similar to those of the lymph node biopsy- and discordant-infiltration by small cells forming lymphoid aggregates, lacking cytological atypia-BM infiltration was defined by histological criteria and further characterized by flow cytometry (FCM). Cell of origin (COO) was determined using Hans’ algorithm. For the clonal relationship between tumor and discordant BM, the VDJH rearrangement was analyzed. Survival analyses were restricted to 189 patients treated with rituximab and chemotherapy. Thirty-six (16%) had concordant, and 37 (16%) discordant BM infiltration. FCM described different indolent lymphomas among discordant cases, clonally related with DLBCL in 10/13 available samples. Median follow-up was 58 months. 5-year-progression-free survival (PFS) for non-infiltrated, discordant and concordant groups was 68%, 65% and 30%, respectively (p < 0.001). Combining COO and BM infiltration, patients with discordant BM and non-germinal center B-cell COO also had decreased 5-year-PFS (41.9%). In multivariate analysis, concordant BM had an independent effect on PFS (HR 2.5, p = 0.01). Five-year cumulative incidence of central nervous system (CNS) relapse was 21%, 4% and 1% in concordant, discordant and non-infiltrated groups, respectively (p < 0.001). In conclusion, concordant BM infiltration represents a subset with poor prognosis, whereas the prognostic impact of discordant BM infiltration could be limited to non-CGB cases.

Advances in Diagnosis and Management of Diffuse Large B-cell Lymphoma

The management of diffuse large B-cell lymphoma (DLBCL) has been gradually evolving since the discovery of its 2 major forms, the germinal center B-like (GCB) and activated B-cell (ABC) types. Although the reference standard for the identification of these cell types is considered gene expression profiling (GEP), currently the only method commercially available is immunohistochemistry (IHC). The application of various IHC-based algorithms and their correlation with GEP and clinical outcome are discussed. Because of the adverse prognostic implications of the non-GCB type and its potential effects on treatment selection, the recently revised World Health Organization classification has included these biologic cell types. The management of double hit lymphomas, which almost exclusively fall under the GCB category, is discussed, together with the double expresser phenotype, which is usually grouped under the non-GCB type. The role of lenalidomide and ibrutinib in the management of the non-GCB type is examined. We also discuss the front-line management of primary mediastinal large cell lymphoma using the EPOCH (etoposide, prednisolone, Oncovin [vincristine], cyclophosphamide, hydroxydaunorubicin [doxorubicin]) regimen and examine new salvage data on immune checkpoint inhibitors for this clinical subtype. The prognosis, clinical features, and management of de novo CD5+ DLBCL are discussed, and newer and promising developments in the management of primary central nervous system lymphomas are presented in detail. The most popular salvage regimens and the application of high-dose chemotherapy with stem cell transplantation are assessed in detail. Finally, data on new treatment tactics such as CART (chimeric antigen receptor T-cell) cells and promising new drugs, including blinatumomab and venetoclax, are presented.

A multicentre retrospective comparison of central nervous system prophylaxis strategies among patients with high-risk diffuse large B-cell lymphoma

Background:

Central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) is a devastating complication; the optimal prophylactic strategy remains unclear.

Methods:

We performed a multicentre, retrospective analysis of patients with DLBCL with high risk for CNS relapse as defined by two or more of: multiple extranodal sites, elevated serum LDH and B symptoms or involvement of specific high-risk anatomical sites. We compared three different strategies of CNS-directed therapy: intrathecal (IT) methotrexate (MTX) with (R)-CHOP ‘group 1' R-CHOP with IT MTX and two cycles of high-dose intravenous (IV) MTX ‘group 2' dose-intensive systemic antimetabolite-containing chemotherapy (Hyper-CVAD or CODOXM/IVAC) with IT/IV MTX ‘group 3'.

Results:

Overall, 217 patients were identified (49, 125 and 43 in groups 1–3, respectively). With median follow-up of 3.4 (range 0.2–18.6) years, 23 CNS relapses occurred (12, 10 and 1 in groups 1–3 respectively). The 3-year actuarial rates (95% CI) of CNS relapse were 18.4% (9.5–33.1%), 6.9% (3.5–13.4%) and 2.3% (0.4–15.4%) in groups 1–3, respectively (P=0.009).

Conclusions:

The addition of high-dose IV MTX and/or cytarabine was associated with lower incidence of CNS relapse compared with IT chemotherapy alone. However, these data are limited by their retrospective nature and warrant confirmation in prospective randomised studies.

Impact of rituximab on incidence of and risk factors for central nervous system relapse in patients with diffuse large B-cell lymphoma: a systematic review and meta-analysis

The impact of rituximab (R) on the incidence of central nervous system (CNS) relapse of diffuse large B-cell lymphoma (DLBCL) is unclear. We performed a meta-analysis to explore the risk factors and assess the association between R-chemotherapy (R-chemo) and CNS relapse. We searched MEDLINE, PubMed, EMBASE and OVID for eligible studies. Published group statistics were extracted from each study for analysis; individual patient data from each study were not accessed. Fixed- or random-effects models were used to estimate the odds ratio (OR) with a 95% confidence interval (CI). Eight studies were identified. The OR for R-chemo compared with identical chemotherapy was 0.70 (95% CI 0.54-0.91). Stage III/IV (OR 2.25, 95% CI 1.64-3.08), International Prognostic Index (IPI) > 1 (OR 2.62, 95% CI 1.59-4.33), performance status (PS) > 1 (OR 1.67, 95% CI 1.23-2.27), elevated lactate dehydrogenase (LDH) (OR 2.23, 95% CI 1.54-3.22), bone marrow involvement (OR 2.85, 95% CI 1.99-4.07), more than one extranodal involvement (OR 2.61, 95% CI 1.93-3.54), presence of B symptoms (OR 1.87, 95% CI 1.37-2.56) and testicular involvement (OR 3.83, 95% CI 1.84-7.97) were associated with increased risks of CNS relapse. This meta-analysis demonstrated a lower incidence of CNS relapse of DLBCL in the rituximab era. The risk of CNS relapse can be assessed by stage, IPI, PS, LDH, presence of B symptoms, number of extranodal sites, bone marrow and testicular involvement.

PET-CT staging of DLBCL accurately identifies and provides new insight into the clinical significance of bone marrow involvement

Routine staging by PET-CT identifies all clinically relevant marrow involvement by DLBCL. Cases with marrow involvement identified by PET-CT have PFS and overall survival similar to stage IV cases without marrow involvement.

Assessment of bone marrow infiltration diagnosed by flow cytometry in canine large B cell lymphoma: prognostic significance and proposal of a cut-off value

The aims of this study were to assess the prognostic significance of bone marrow (BM) infiltration in canine large B cell lymphoma (LBCL) and to establish cut-off values for designating the BM as infiltrated by lymphoid blasts. The degree of BM infiltration by large CD21 positive cells in dogs with LBCL was assessed by flow cytometry (FC) and related to time to progression (TTP) and lymphoma-specific survival (LSS). Forty-six dogs were prospectively enrolled, staged and treated with a dose-intense chemotherapeutic protocol. BM infiltration was directly correlated with peripheral blood infiltration (P=0.001), high lactate dehydrogenase activity (P=0.0024) and substage b disease (P<0.001). In the univariate analysis, there was a significant association between BM infiltration diagnosed by FC and both TTP (P=0.001) and LSS (P<0.001). Substage was the only factor associated with TTP in the multivariate analysis (P=0.002), whereas substage (P<0.001) and anaemia (P=0.008) were associated with LSS. A cut-off of 3% BM infiltration had the strongest prognostic value, since it discriminated between dogs with a poorer prognosis (median TTP 69 days; median LSS 155 days) and dogs with a better prognosis (median TTP 149 days; median LSS 322 days). BM analysis is an essential step in the staging of LBCL. The presence of BM infiltration by FC at diagnosis is a negative prognostic indicator in canine LBCL.

Central nervous system involvement in diffuse large B-cell lymphoma

BACKGROUND

Malignant lymphoma with central nervous system (CNS) involvement has an extremely poor prognosis. We retrospectively studied the risk factors for CNS involvement in patients with diffuse large B-cell lymphoma (DLBCL) treated by cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or rituximab (R) -CHOP chemotherapy.

PATIENTS AND METHODS

We studied 375 consecutive patients who were newly diagnosed with DLBCL between 1996 and 2006. Patients with primary CNS involvement and patients who received CNS prophylaxis were excluded. All the patients received CHOP (n = 172) or R-CHOP (n = 203) chemotherapy. The following variables were assessed for their potential to predict CNS involvement: gender, age, serum lactate dehydrogenase (LDH) level, performance status, clinical stage, number of extranodal involvements, International Prognostic Index (IPI), bone marrow involvement, presence of a bulky mass, presence of B symptom, and treatment.

RESULTS

CNS involvement was observed in 13 cases (3.5%). In univariate analysis, LDH more than normal range, LDH more than twice as normal range, high IPI, bone marrow involvement, and systemic relapse were the predictors for CNS involvement. In multivariate analysis, no risk factors were detected for CNS involvement. The use of rituximab did not have an impact on CNS involvement.

CONCLUSIONS

The incidence of CNS involvement does not decrease in rituximab-era.