Prognostic value of the International Scoring System and response in patients with advanced Waldenstrom macroglobulinemia

Does early disease progression predicts survival after first line-treatment of Waldenström macroglobulinemia?

In symptomatic Waldenström macroglobulinemia (sWM) patients, prognosis is assessed with the international prognostic scoring system (IPSSWM). In follicular lymphoma and other B‐cell and T‐cell lymphomas, disease progression within 24 months (POD24) or (in patients without POD24) after 24 months has been proposed as the start date for stratifying subsequent survival. In the present report, we assessed in a large series of 472 sWM patients, the prognostic value of this new dynamic endpoint already reported in many other lymphomas subtypes. The 3 year subsequent survival for patients with POD24 was 75% and 93% for patients without POD24. In sWM patients, departure from the proportional hazards assumption complicated this analysis. In patients without POD24, the median subsequent progression‐free survival time of 43 months accounted for favorable outcome, whereas survival after progression was not influenced by the time to progression. In addition, sensitivity analysis showed that the baseline IPSSWM score also influenced survival after POD24. In sWM patients, we conclude that the apparent difference in survival after POD24 or the 24 months time‐point (in patients without POD24) is mainly explained by the prolonged subsequent progression free survival of latter patients. Indeed, the mortality after progression is not influenced by the time to this event.

Efficacy of Autologous and Allogeneic Hematopoietic Cell Transplantation in Waldenström Macroglobulinemia: A Systematic Review and Meta-analysis

INTRODUCTION

Waldenström macroglobulinemia (WM) is an IgM-producing lymphoproliferative disorder that remains incurable. Patients with high-risk disease have an overall survival (OS) of less than 3 years. Both autologous (AHCT) and allogeneic (allo-HCT) hematopoietic cell transplantation (HCT) are prescribed for treatment of WM despite a lack of randomized controlled studies.

MATERIALS AND METHODS

We performed a comprehensive literature search using PubMed/Medline and EMBASE on September 10, 2019. Data on clinical outcomes related to benefits and harms was extracted independently by 3 authors. Fifteen studies (8 AHCT [n = 278 patients], 7 allo-HCT [n = 311 patients]) were included in this systematic review/meta-analysis.

RESULTS

Pooled OS, progression-free survival (PFS), and nonrelapse mortality (NRM) rates post AHCT were 76% (95% confidence interval [CI], 65%-86%), 55% (95% CI, 42%-68%), and 4% (95% CI, 1%-7%), respectively. Pooled OS, PFS, and NRM rates post allografting were 57% (95% CI, 50%-65%), 49% (95% CI, 42%-56%), and 29% (95% CI, 23%-34%), respectively. OS and PFS rates were reported at 3 to 5 years, and NRM was reported at 1 year in most studies. Pooled ORR (at day 100) post AHCT and allo-HCT were 85% (95% CI, 72%-94%) and 81% (95% CI, 69%-91%), respectively. Pooled complete response rates post AHCT and allo-HCT were 22% (95% CI, 17%-28%) and 26% (95% CI, 7%-50%), respectively. Relapse rates post AHCT and allo-HCT were 42% (95% CI, 30%-55%) and 23% (95% CI, 18%-28%), respectively.

CONCLUSIONS

Our results show that both AHCT and allo-HCT are effective in the treatment of WM. A 2-fold lower relapse rate but a 7-fold higher NRM was noted for allo-HCT compared with AHCT. The role of transplant in WM needs to be addressed in the era of novel agents.

Onsets of progression and second treatment determine survival of patients with symptomatic Waldenström macroglobulinemia

Few reports assess prognosis during follow-up of patients with symptomatic Waldenström macroglobulinemia (WM). In 121 WM patients treated between 1993 and 2016, we analyzed the prognostic role during the clinical course of the initial International Prognostic Scoring System for WM (IPSSWM). Then, we assessed onset of response, progression, and second treatment initiation coded as time-dependent covariates. High-risk IPSSWM was an adverse prognostic factor for survival after first treatment initiation (SAFTI). Nevertheless, the corresponding Dxy concordance index obtained in multiple landmark analyses decreased from 0.24 to 0.08 during the first 6 years, in accordance with a departure from the proportional hazard assumption. By contrast with onset of response (whatever its level), onset of progression and initiation of second-line treatment retained prognostic value for SAFTI (P = .02 and P = .006, respectively). These findings were confirmed in cause-specific Cox models for deaths related to WM, but not for unrelated deaths. Time to progression after first-line treatment and time to initiation of second-line treatment had no prognostic value for survival after these 2 events. These results were confirmed in an independent series of 119 patients homogeneously treated with chemoimmunotherapy. Finally, after second-line and third-line treatment, onset of progression had significant prognostic value for subsequent risk of related death only. Thus, taking initial IPSSWM and delayed response to treatment into account, only onset of progression and second treatment initiation provided additional prognostic information for SAFTI. Therefore, progression-free survival or time to next treatment may be satisfactory surrogate end points of SAFTI in WM.

The role of stem cell transplantation in Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia (WM) is an indolent B-cell lymphoma, which is highly chemosensitive, with an overall response rate over 90% to novel agents. However, most patients eventually relapse after response to first-line chemotherapy, necessitating further treatment. The possibility of long-lasting remission after high-dose cytotoxic chemotherapy followed by stem cell rescue is high in WM due to the chemosensitive nature of the disease and lower proliferative activity compared to multiple myeloma. In this paper, we have reviewed current evidence on autologous (auto-) and allogeneic (allo-) stem cell transplantation (SCT) in WM. Auto-SCT can be safely performed in WM and is recommended as second-line treatment or beyond in eligible patients. It is associated with extremely low transplant-related mortality. Allo-SCT is effective in WM with incremental benefit due to graft-versus-WM effect, but is associated with high non-relapse mortality of 30%, hence should be preferably considered investigational as part of clinical trials in selected patients who have exhausted other treatment options.

Treatment recommendations for patients with Waldenström macroglobulinemia (WM) and related disorders: IWWM-7 consensus

Waldenström macroglobulinemia (WM) is a distinct B-cell lymphoproliferative disorder for which clearly defined criteria for the diagnosis, initiation of therapy, and treatment strategy have been proposed as part of the consensus panels of International Workshops on WM (IWWM). As part of the IWWM-7 and based on recently published and ongoing clinical trials, the panels updated treatment recommendations. Therapeutic strategy in WM should be based on individual patient and disease characteristics (age, comorbidities, need for rapid disease control, candidacy for autologous transplantation, cytopenias, IgM-related complications, hyperviscosity, and neuropathy). Mature data show that rituximab combinations with cyclophosphamide/dexamethasone, bendamustine, or bortezomib/dexamethasone provided durable responses and are indicated for most patients. New monoclonal antibodies (ofatumumab), second-generation proteasome inhibitors (carfilzomib), mammalian target of rapamycin inhibitors, and Bruton's tyrosine kinase inhibitors are promising and may expand future treatment options. A different regimen is typically recommended for relapsed or refractory disease. In selected patients with relapsed disease after long-lasting remission, reuse of a prior effective regimen may be appropriate. Autologous stem cell transplantation may be considered in young patients with chemosensitive disease and in newly diagnosed patients with very-high-risk features. Active enrollment of patients with WM in clinical trials is encouraged.

Excellent long-term survival of 170 patients with Waldenström's macroglobulinemia treated in private oncology practices and a university hospital

The purpose of this study was to compare treatment and outcome of patients with Waldenström's macroglobulinemia (WM) in four private oncology practices (PP) and a university hospital (UH) in southwest Germany. We retrospectively reviewed the charts of all patients with WM of the last two decades of four PP in Mannheim, Heidelberg, Karlsruhe, and Speyer and the Department of Hematology of the University of Heidelberg. One hundred seventy patients could be identified, 74 from PP, 96 from the UH. Median age was 63.3 years. Patients from PP were older (median 65.3 vs. 62.5 years, p = 0.01). Only 54 % of patients from PP have received treatment during the observation time, as compared to 78.1 % of the UH (p < 0.001). In PP, 35 % of treated patients have received rituximab, as compared to 62.6 % of the patients of the UH (p < 0.001). Sixty percent of treated patients of PP have received bendamustine, as compared to only 8 % of the patients of the UH (p < 0.001). Time to first treatment was significantly shorter in patients from the UH compared to PP (median 13.7 vs. 52.9 months, p = 0.05). A trend towards a better overall survival was observed for patients treated with a rituximab-containing first-line regimen. The International Prognostic Scoring System for WM had significant prognostic value. Median overall survival was 25.0 years and did not differ between PP and UH. Despite different treatment strategies between PP and UH today overall survival of patients with WM is excellent, and better than previously reported.

Risk stratification in Waldenström macroglobulinemia

Waldenström macroglobulinemia is characterized by the production of serum monoclonal IgM and lymphoplasmacytic bone marrow infiltration. At least 25% of patients are asymptomatic at diagnosis and treatment is only mandatory in cases of symptomatic disease. Beside reports on treatment results, reviewing risk assessment is another way to describe the clinical course of the disease. This information may be particularly useful when numerous treatment options are available. While the introduction of new treatment approaches reinforces the need for careful risk assessment, the identification of useful prognostic information requires prolonged follow-up in patients who have not been treated with current therapeutic options. This limitation should be taken into account when using and interpreting available prognostic information, especially survival estimates.

Waldenström macroglobulinemia: a review of the entity and its differential diagnosis

The definition of Waldenström macroglobulinemia (WM), originally described in 1944, has been refined substantially over time. The current fourth edition of the World Health Organization of lymphoid neoplasms, in large part, adopted criteria proposed for WM at a consensus conference in 2002. WM is defined as lymphoplasmacytic lymphoma involving the bone marrow associated with a serum immunoglobulin (Ig) M paraprotein of any concentration. Morphologically, WM is composed of a variable mixture of lymphocytes, plasmacytoid lymphocytes, and plasma cells. Immunophenotypically, the neoplastic cells express monotypic IgM and light chain: B lymphocytes express pan-B-cell antigens and surface Ig are usually negative for CD5 and CD10; and plasma cells are typically positive for CD138, CD38, CD45, cytoplasmic Ig, and CD19 (in a substantial subset of cases). The putative cell of origin of WM is a postantigen selected memory B-cell that has undergone somatic hypermutation. The most common cytogenetic abnormality in WM is del(6q), usually in the region 6q23-24.3, present in 40% to 50% of cases. IGH gene translocations are rare and recurrent chromosomal translocations or gene aberrations have not been identified in WM. Here, we provide a historical perspective of WM, review clinical and pathologic aspects of the disease as it is currently defined, and discuss some practical issues in the differential diagnosis of WM that pathologists encounter in the signout of cases.