Risk stratification in Waldenström macroglobulinemia

Frontline Management of Waldenström Macroglobulinemia with Chemoimmunotherapy

Despite the introduction of effective novel agents, chemoimmunotherapy (CIT), with its widespread use, retains relevance and is one of the 2 vastly disparate strategies to treat Waldenström macroglobulinemia (WM), the alternative being the Bruton tyrosine kinase inhibitor (BTKi)-based approach. Considerable evidence over the past decades supports the integration of the monoclonal anti-CD20 antibody, rituximab, to the CIT backbone in WM, a CD20+ malignancy. Besides substantial efficacy, the finite duration of the treatment, coupled with lower rates of cumulative and long-term, clinically significant adverse effects and greater affordability, make CIT appealing, notwithstanding the lack of quality-of-life data with such an approach in WM. A phase 3 randomized controlled trial reported substantially higher efficacy and a more favorable safety profile of the bendamustine-rituximab (BR) doublet compared with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) among patients with WM. Subsequent studies reaffirmed its high efficacy and tolerability, making BR the mainstay of managing treatment-naïve patients with WM. High-quality evidence supporting the use of BR over Dexamethasone, Rituximab, and Cyclophosphamide (DRC), another commonly used regimen, is lacking, as is its comparison with the continuous BTKi-based approach. However, DRC appeared less potent than BR in cross-trial comparisons and retrospective series involving treatment-naïve patients with WM. Additionally, a recent retrospective, international study demonstrated comparable outcomes with fixed-duration BR and continuous ibrutinib monotherapy among previously untreated, age-matched patients exhibiting MYD88L265P mutation. However, unlike ibrutinib, BR appears effective irrespective of the MYD88 mutation status. CIT, preferably BR, is well suited to serve as the control arm (comparator) regimen against which novel targeted agents may be evaluated as frontline therapies for WM in high-quality trials. Purine analog-based CIT has been extensively evaluated in WM, although its use has waned, even in the multiply relapsed patient population, as effective and safer alternatives emerge.

Rare presentation of Waldenström’s macroglobulinaemia requiring bilateral above-knee amputations: a case report

Background

Waldenström’s macroglobulinaemia is a rarely encountered B-lymphocytic malignancy. Waldenström’s macroglobulinaemia-associated paraproteinaemia is linked to an increase in serum viscosity, which results in a hypercoagulable state. Burning bilateral foot pain in a man with alcohol dependence and controlled atrial fibrillation presenting to the emergency department was attributed to peripheral neuropathy, given satisfactory angiographic evidence of bilateral foot arterial blood supply. Subsequently, his presentation as an emergency with acute bilateral critical lower limb ischemia that was managed by bilateral above-knee amputations, prompted a wider search for other etiologies. We present a hitherto unreported case of Waldenström’s macroglobulinaemia-related acute bilateral lower limb ischemia, which required bilateral above-knee amputations.

Case presentation

A 50-year-old Caucasian man, who was an alcohol dependent heavy smoker, presented with burning pain in his right foot that was deemed to be related to alcoholic neuropathy. A computerized tomographic angiogram demonstrated an occluded right distal anterior tibial artery but a patent posterior tibial artery supplying the foot arch, findings that were associated with noncritical ischemia. After multiple presentations within a week, he was admitted following sudden clinical deterioration with acute confusion, hyponatremia, and bilateral foot pain. Over the course of 24 hours, the patient deteriorated rapidly, with bilateral lower limb ischemia requiring bilateral above-knee amputations. Subsequent investigations revealed a diagnosis of Waldenström’s macroglobulinaemia.

Conclusions

To the best of our knowledge, this is the only reported case of Waldenström’s macroglobulinaemia-induced bilateral lower limb ischemia requiring major bilateral amputations.

Incidence, prevalence, mortality, and causes of death in Waldenström macroglobulinemia: a nationwide, population-based cohort study

BACKGROUND

The epidemiological features of Waldenström macroglobulinemia (WM) have seldom been investigated at a national level, particularly in East Asia. The goal of our study is to present the incidence, prevalence, mortality, survival with competing risks, and causes of death of patients with WM.

METHODS

We used a national population-based database, operated by the Health Insurance Review and Assessment Service of the Korean government. This data includes information on all WM patients diagnosed according to uniform criteria, between 2003 and 2016.

RESULTS

The total number of patients newly diagnosed with WM during the study period was 427, with a male-to-female ratio of 3.2:1. The incidence increased from 0.03 to 0.10 per 105 between 2003 and 2016, and the prevalence was 0.42 per 105 in 2016. A total of 217 patients with WM died during the study period (standardized mortality ratio = 7.57), and the overall survival (OS) of WM patients was 47.5%. On multivariate analysis, older age was associated with worse OS (P <  0.0001). WM was the most common cause of death (n = 102, 48.6%), followed by other malignant neoplasms (n = 82, 39.0%).

CONCLUSIONS

The national incidence of WM in Korea, a racially homogeneous country in Asia, was lower than that in previous reports from other countries, reflecting ethnic disparities. However, the incidence increased, and mortality was the highest ever reported. The main cause of death was WM in itself. This study reflects the need for greater awareness of WM, particularly in Asian countries.

High-Dose Therapy and Hematopoietic Stem Cell Transplantation in Waldenström Macroglobulinemia

Waldenström macroglobulinemia (WM) is an indolent low-grade non-Hodgkin lymphoma characterized by bone marrow infiltration by lymphoplasmacytic cells and associated clonal IgM paraproteinemia. Recent insights into the biology and genomic characteristics of WM have provided a further platform for more targeted therapies. Despite the high response rates and better depth and duration of responses, the disease remains incurable. This review focuses on use of the high-dose therapy with either autologous or allogeneic hematopoietic stem cell transplantation.

Waldenström macroglobulinemia with extramedullary involvement at initial diagnosis portends a poorer prognosis

BACKGROUND

The prognostic importance of extramedullary involvement in patients with Waldenström macroglobulinemia (WM) at diagnosis and treatment options for these patients has not been well evaluated. In this study, we investigated the clinical manifestations, biological features, and effect of first-line therapy on the outcome of WM patients diagnosed with extramedullary involvement (EMWM) vs those with only bone marrow involvement (BMWM).

METHODS

We analyzed the clinical data of 312 WM patients diagnosed with EMWM (n = 106) and BMWM (n = 206) at The University of Texas MD Anderson Cancer Center from 1994 to 2014. EMWM was confirmed by biopsy, positron emission tomography-computed tomography, or magnetic resonance imaging, and clinical laboratory analyses.

RESULTS

Characteristics associated with EMWM were male sex (P = 0.027), age younger than 65 years (P = 0.048), presence of B symptoms (P < 0.001), high serum beta-2 macroglobulin (P < 0.001) level, low serum albumin level (P = 0.036), and cytogenetic abnormalities (P = 0.010). Kaplan-Meier survival analysis results showed that EMWM patients had a significantly shorter median overall survival (P < 0.001) and progression-free survival (PFS) (P < 0.001) than did BMWM patients. Chemotherapy combined with targeted therapy improved PFS for BMWM patients (P = 0.004) but not for EMWM patients. Additionally, initial treatment with rituximab significantly improved the PFS of BMWM patients (P = 0.012) but had no effect on EMWM patients. However, EMWM patients treated with nucleoside analogs attained a better PFS than those who did not (P = 0.021).

CONCLUSIONS

We show that extramedullary involvement at diagnosis is an adverse prognostic factor in WM patients and that first-line therapy with nucleoside analogs improved PFS for patients with EMWM. The study provides unique clinical and treatment observations in subtypes of WM patients.

Genetic factors and pathogenesis of Waldenström's macroglobulinemia

Waldenström's macroglobulinemia (WM) is an indolent but incurable B-cell malignancy. Over the last decade, advances in the molecular field brought about by the use of high-throughput genomic analyses-including array-based comparative genomic hybridization and massively parallel genome sequencing-have considerably improved our understanding of the genetic basis of WM. Its pathogenesis, however, remains fragmented. Important steps have been made in elucidating the underlying aberrations and deregulated mechanisms of the disease, and thereby providing invaluable information for identifying biomarkers for disease diagnosis, risk stratification, and therapeutic approaches. We review the genetic basis of the disease.