Occupational solvent exposure and adult chronic lymphocytic leukemia: No risk in a population-based case-control study in four Nordic countries

The global burden of childhood and adolescent leukaemia and attributable risk factors: An analysis of the Global Burden of Disease Study 2019

Background

Aim of this study is to estimate the burden of leukaemia in children and adolescents, as well as the socio-demographic index (SDI), for 21 regions around the world from 1990 to 2019.

Methods

We also conducted an analysis of the Joinpoint model to estimate the time trend of childhood and adolescent leukaemia incidence, death, and disability-adjusted life years (DALYs) rate and age-standardised rates (ASR) of leukaemia.

Results

According to our analysis, the middle SDI experienced the highest decrease in incidence rate between 1990 and 2019, with an average annual percent change (AAPC) of -2.8 (95% confidence interval (CI) = -3.0, -2.6, P < 0.05). We showed that DALYs of children leukaemia is 155.98 (95% uncertainty interval (UI) = 127.18, 182.64) for global male, however, global female leukaemia DALYs is 117.65 (95% UI = 102.07, 132.70).

Conclusions

Despite the observed decline in the incidence, mortality, and DALYs of leukaemia over the last three decades, the burden of childhood and adolescent leukaemia remains high, particularly in areas with lower SDI.

Biology and Therapeutic Properties of Mesenchymal Stem Cells in Leukemia

This comprehensive review delves into the multifaceted roles of mesenchymal stem cells (MSCs) in leukemia, focusing on their interactions within the bone marrow microenvironment and their impact on leukemia pathogenesis, progression, and treatment resistance. MSCs, characterized by their ability to differentiate into various cell types and modulate the immune system, are integral to the BM niche, influencing hematopoietic stem cell maintenance and functionality. This review extensively explores the intricate relationship between MSCs and leukemic cells in acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, and chronic lymphocytic leukemia. This review also addresses the potential clinical applications of MSCs in leukemia treatment. MSCs' role in hematopoietic stem cell transplantation, their antitumor effects, and strategies to disrupt chemo-resistance are discussed. Despite their therapeutic potential, the dual nature of MSCs in promoting and inhibiting tumor growth poses significant challenges. Further research is needed to understand MSCs' biological mechanisms in hematologic malignancies and develop targeted therapeutic strategies. This in-depth exploration of MSCs in leukemia provides crucial insights for advancing treatment modalities and improving patient outcomes in hematologic malignancies.

Impending splenic rupture as indicator of atypical chronic lymphocytic leukemia: A case report from Saudi Arabia

BACKGROUND

Chronic lymphocytic leukemia (CLL) is one of the hematological malignancies in which the bone marrow overproduces mature, dysfunctional lymphocytes. Affected lymphocytic cells can affect the lymph nodes, spleen, liver, bone marrow, and rarely other organs. Spontaneous rupture of the spleen is a rare health condition, with a few cases caused by CLL. Since the preliminary presentation of either impending or real splenic rupture is unusual and requires recording and reporting, this case report was developed.

CASE REPORT

A 55-year-old male patient presented with a significant weight loss of 20 kg, loss of appetite, fatigue, abdominal pain, and early satiety. Clinical examination revealed massive splenomegaly 22 cm below the costal margin, otherwise unremarkable on systemic examination. The size and dimensions of the spleen were confirmed by computed tomography of the body. The patient underwent a bone marrow biopsy, which was suggestive of atypical CLL. Due to the rapid progression of the size of the spleen and the pattern of impending rupture of the spleen, an emergency splenectomy was performed, and the histopathological report confirmed low-grade B-cell non-Hodgkin's lymphoma, mostly typical of CLL.

CONCLUSION

Given the rarity of cases, continuous data recording and reporting is required to enrich the scientific literature and share experiences from case to case. This will create a complete picture of this health condition across diverse regions and countries.

Occupational risk variation of nasopharyngeal cancer in the Nordic countries

Background

The aim of this study was to estimate occupational risk variation in the incidence of nasopharyngeal cancer (NPC) in a large population-based cohort of the Nordic Occupational Cancer (NOCCA) study.

Methods

This study is based on a cohort of almost 15 million persons from Denmark, Finland, Iceland, Norway and Sweden, with 2898 nasopharyngeal cancer cases diagnosed in 1961–2005. The data on occupations were gathered from population censuses and cancer data from the national cancer registries. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were estimated using the national NPC incidence rates as the reference.

Results

There were 1980 male and 918 female NPC patients. The highest SIRs of NPC were observed among male waiters (SIR 3.69, 95% CI 1.91–6.45) and cooks and stewards (SIR 2.24, 95% CI 1.16–3.91). Among women, launderers had the highest SIR of NPC (2.04, 95% CI 1.02–3.65). Significantly decreased SIRs were found among male farmers (SIR 0.79, 95% CI 0.68–0.92) and male textile workers (SIR 0.49, 95% CI 0.22–0.93).

Conclusions

This study suggests that NPC may be associated with several work-related exposure agents such as smoking, kitchen air pollution and solvents. In future, occupational exposure-risk relations should be studied to understand more about causality and to assess effective prevention strategies.

Trends in Disease Burden of Chronic Lymphocytic Leukemia at the Global, Regional, and National Levels From 1990 to 2019, and Projections Until 2030: A Population-Based Epidemiologic Study

Background

The prognosis of chronic lymphocytic leukemia (CLL) has been improved dramatically, but there are limited studies focusing on CLL disease burden on a global scale. We aimed to evaluate the accurate assessment of the disease burden of CLL that may provide more detailed epidemiological information for rational policies.

Methods

The main source of the data was the Global Burden of Disease (GBD) study 2019. Incident cases, death cases, disability-adjusted life years (DALYs), and their corresponding age-standardized rates (ASRs) from 1990 to 2019 were used to describe the burden of CLL. Data about attributable risk factors were also extracted and analyzed. Bayesian age-period-cohort (BAPC) models were used to assess and project the incidence and mortality rates till 2030.

Results

Globally, the incidence of CLL had been increasing. Deaths and DALYs decreased slightly. The burden of death and DALY is affected by socio-demographic index (SDI). The incidence rate, death rate, and DALY rate of CLL increased significantly with age. Male-to-female ratios of incidence rates varied in different SDI quintiles. Smoking, high body mass index, and occupational exposure to benzene or formaldehyde were the potential risk factors related to CLL. Global ASIRs might tend to increase until 2030, while ASDR would decrease until 2030.

Conclusion

The disease burden of CLL decreased in higher SDI countries but increased in lower ones. Strategies for early detection of asymptomatic CLL, development of novel drugs, and measures against attributable factors should be implemented to combat CLL burden.

Evaluation of the carcinogenicity of dichloromethane in rats, mice, hamsters and humans

Dichloromethane (DCM) is a high production volume chemical (>1000 t/a) mainly used as an industrial solvent. Carcinogenicity studies in rats, mice and hamsters have demonstrated a malignant tumor inducing potential of DCM only in the mouse (lung and liver) at 1000-4000 ppm whereas human data do not support a conclusion of cancer risk. Based on this, DCM has been classified as a cat. 2 carcinogen. Dose-dependent toxicokinetics of DCM suggest that DCM is a threshold carcinogen in mice, initiating carcinogenicity via the low affinity/high capacity GSTT1 pathway; a biotransformation pathway that becomes relevant only at high exposure concentrations. Rats and hamsters have very low activities of this DCM-metabolizing GST and humans have even lower activities of this enzyme. Based on the induction of specific tumors selectively in the mouse, the dose- and species-specific toxicokinetics in this species, and the absence of a malignant tumor response by DCM in rats and hamsters having a closer relationship to DCM toxicokinetics in humans and thus being a more relevant animal model, the current classification of DCM as human carcinogen cat. 2 remains appropriate.

Excess cumulative incidence estimation for matched cohort survival studies

We suggest a regression approach to estimate the excess cumulative incidence function (CIF) when matched data are available. In a competing risk setting, we define the excess risk as the difference between the CIF in the exposed group and the background CIF observed in the unexposed group. We show that the excess risk can be estimated through an extended binomial regression model that actively uses the matched structure of the data, avoiding further estimation of both the exposed and the unexposed CIFs. The method naturally deals with two time scales, age and time since exposure and simplifies how to deal with the left truncation on the age time-scale. The model makes it easy to predict individual excess risk scenarios and allows for a direct interpretation of the covariate effects on the cumulative incidence scale. After introducing the model and some theory to justify the approach, we show via simulations that our model works well in practice. We conclude by applying the excess risk model to data from the ALiCCS study to investigate the excess risk of late events in childhood cancer survivors.

Bilateral breast implant associated chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL): A case report

INTRODUCTION

An estimated 30.000 breast implants are placed in the Netherlands annually. An increasing amount of reports have linked implants to the rare anaplastic large cell lymphoma (ALCL). Other implant-related lymphomas, such as those of B-cell lineage, are much rarer.

PRESENTATION OF CASE

A 62-year-old female presented with pain and Baker grade III capsular contraction of the right breast. Subpectorally placed textured anatomical implants had been in situ for 26 years after cosmetic augmentation. Magnetic Resonance Imaging (MRI) showed bilateral implant leakage. Explantation of both implants confirmed bilateral leakage after which symptoms went into remission. Three months later our patient noticed an erythematous area, scar swelling and serous fluid leakage on the lateral side of the inframammary fold of the right breast. Siliconomas were excised bilaterally together with a partial capsulectomy on the left. Histopathology and immunohistochemical analysis showed monotonous small cell B-lymphocytic infiltration (CD20+, CD5+, CD23+, ALK-) in both capsules, highly suggestive for chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL).

DISCUSSION

CLL/SLL are classified as nearly the same disease. The primary difference is the localization; CLL is found the bone marrow and blood whereas SLL is predominantly in the lymph nodes and spleen. There are no previous descriptions of bilateral CLL/SLL found in periprosthetic capsules.

CONCLUSION

Breast implants are increasingly linked to various malignancies. In most cases, including our patient, implant explantation together with long-term follow-up suffices. MRI yields additional value in early stage diagnosis. More research is required to further optimize multidisciplinary care and improve patient outcomes.

A mixtures approach to solvent exposures and amyotrophic lateral sclerosis: a population-based study in Denmark

Studies of occupational solvent exposures and amyotrophic lateral sclerosis (ALS) have been conflicting. We conducted a population-based case-control study of mixed occupational solvent exposures and ALS. Using the Danish National Patient Registry, we identified ALS cases in Denmark from 1982 to 2013, and matched them to 100 controls based on sex and birth year. We estimated cumulative exposures to solvents (benzene, methylene chloride, toluene, trichloroethylene, perchloroethylene, and 1,1,1-trichloroethane) via job exposure matrices and applied them to occupational history from the Danish Pension Fund. Sex-stratified conditional logistic regression analyses revealed higher adjusted odds of ALS for men with exposure to benzene (aOR = 1.20; 95% CI 1.02, 1.41) and methylene chloride (aOR = 1.23; 95% CI 1.07, 1.42). We used weighted quantile sum regression to explore combined solvent exposures and risk of ALS in exposed subjects and found increased odds of 26 to 28% in all exposure lag periods for every one-unit increase in the mixture index in men. Weights of methylene chloride predominated the mixture index in all lag periods. Our study suggests an increased risk of ALS in men exposed to multiple solvents, with the greatest influence being from methylene chloride. These findings highlight the need to utilize mixtures analysis when considering co-occurring exposures.

Excess risk estimation for matched cohort survival data

We present an excess risk regression model for matched cohort data, where the occurrence of some events for individuals with a disease is compared to that of healthy controls that are matched at the onset-of-disease by various factors. By using the matched structure, we show how to estimate the excess risk and its dependence on covariates on both proportional and additive form. We remove the individual effects on background mortality related to matching factors by considering differences. The model handles two different time scales, namely attained age and follow-up time. First, we solve estimating equations for the non-parametric and parametric components of the excess risk model, providing large sample properties for the suggested estimators. Next, we report results from a simulation study. Lastly, we describe an application of the method on childhood cancer data, to study the excess risk of cardiovascular events in adults' life among childhood cancer survivors.

On the front line: first choice pharmacotherapeutics for chronic lymphocytic leukemia

INTRODUCTION

Chronic lymphocytic leukemia (CLL) is a common hematologic malignancy with a highly variable clinical course. Frontline treatments include cytotoxic chemotherapies, immunotherapies, and small molecule inhibitors. Clinical and molecular factors guide treatment initiation and selection. Over the last decade, refinement of CLL risk stratification tools and growth of the arsenal of effective therapeutics have profoundly improved outcomes. These advances have concurrently increased the complexity of managing the early phases of treatment.

AREAS COVERED

This review describes the factors considered in the determination of first-line treatment of CLL. Areas of emphasis include assessment of patient fitness, disease classification and risk stratification, and the mechanisms, efficacy, and toxicities associated with available pharmacotherapeutics.

EXPERT OPINION

Multiple different treatments may be appropriate for a specific clinical scenario, and selection among them requires discussion of relative risks and benefits. Advances in frontline CLL treatment will continue to shift the treatment paradigm toward prioritizing quality of life alongside survival, limiting treatment and toxicity, and the development of biologically rational synergistic drug combinations and sequences.