Clinical impact of metformin in diabetic diffuse large B-cell lymphoma patients: a case-control study

Understanding the interplay between chronic lymphocytic leukemia and type 2 diabetes

INTRODUCTION

Comorbidities play an important role in the management of chronic lymphocytic leukemia (CLL) and may influence survival and treatment outcomes. Considering the aging general population and increasing incidence of type 2 diabetes (T2D), a comprehensive understanding of the interplay between CLL and T2D is essential for optimizing care and outcomes.

AREAS COVERED

We present current knowledge on co-existing CLL and T2D including prevalence, shared etiology and risk factors and how the conditions and treatment hereof may influence the outcome of one another. A literature search was performed using PubMed with the cutoff date on 1 February 2024.

EXPERT OPINION

The increased mortality observed in persons with CLL who have co-existing T2D is partially ascribed to infections, prompting physicians managing individuals with both conditions to consider closer monitoring during instances of infection and individualized prophylaxis. People with CLL and T2D should be managed for CLL in accordance with the international working group on CLL criteria, and we recommend that physicians exercise particular care not to delay treatment for these individuals. Multidisciplinary approaches with involvement of several specialties may be required for optimal supportive care of co-occurring T2D and CLL.

Metformin and risk of hematological cancers in patients with diabetes: a systematic review and meta-analysis

FUNDING

No external funding.

Independent predictors of mortality and 5-year trends in mortality and resource utilization in hospitalized patients with diffuse large B cell lymphoma

Background

This retrospective study analyzed factors influencing all-cause inpatient mortality in 80,930 adult patients (2016-2020) with diffuse large B cell lymphoma using the National Inpatient Sample database.

Methods

Utilizing ICD-10 codes, patients were identified, and statistical analysis was conducted using STATA. Fisher's exact and Student's t tests compared proportions and variables, multivariate logistic regression examined mortality predictors, and a 5-year longitudinal analysis identified mortality and resource utilization trends.

Results

The inpatient mortality rate was found to be 6.56% with a mean age of 67.99 years. Several hospital- and patient-level factors including specific comorbidities such as congestive heart failure, atrial fibrillation, acute kidney injury, chronic obstructive pulmonary disease, liver failure, pancytopenia, tumor lysis syndrome, and severe protein-calorie malnutrition were independently associated with inpatient mortality. Hospitalization costs showed an increasing trend, impacting the overall population and survivors.

Conclusion

These insights may refine risk assessment, treatment selection, and interventions.

Infectious complications and long-term outcomes in patients with diffuse large B-Cell lymphoma and diabetes mellitus

Febrile neutropenia (FN) is a major complication in patients with diffuse large B-Cell lymphoma (DLBCL). Diabetes mellitus (DM) has deleterious effects on the immune system resulting in an increased risk of infections. We evaluated patients with DLBCL who started frontline treatment with R-CHOP, and compared outcomes according to presence of DM comorbidity. Between 2013 and 2018, 218 patients with DLBCL were included. 46 patients (21%) had DM. Rate of admissions for FN was higher for patients with DM (0.7 vs. 0.46 admissions/patient, p = .016), also after age and gender-matched subgroup analysis (p = .004). Improved glycemic control during FN hospitalizations was associated with shorter hospitalizations. Metformin was associated with improved median overall survival in diabetic patients (89 vs. 64 months, p = .018). In conclusion, Patients with DLBCL and DM had higher rates of FN hospitalizations. Improved glycemic control during FN hospitalization was associated with shorter length of stay.

Metformin and Cancer, an Ambiguanidous Relationship

The deregulation of energetic and cellular metabolism is a signature of cancer cells. Thus, drugs targeting cancer cell metabolism may have promising therapeutic potential. Previous reports demonstrate that the widely used normoglycemic agent, metformin, can decrease the risk of cancer in type 2 diabetics and inhibit cell growth in various cancers, including pancreatic, colon, prostate, ovarian, and breast cancer. While metformin is a known adenosine monophosphate-activated protein kinase (AMPK) agonist and an inhibitor of the electron transport chain complex I, its mechanism of action in cancer cells as well as its effect on cancer metabolism is not clearly established. In this review, we will give an update on the role of metformin as an antitumoral agent and detail relevant evidence on the potential use and mechanisms of action of metformin in cancer. Analyzing antitumoral, signaling, and metabolic impacts of metformin on cancer cells may provide promising new therapeutic strategies in oncology.

Diabetes and the Prognosis in Patients With Non-Hodgkin Lymphoma: A Meta-analysis of Cohort Studies

BACKGROUND

Consensus lacks regarding the association between diabetes mellitus (DM) and the prognosis of patients with non-Hodgkin lymphoma (NHL). We aimed to systematically evaluate the above association, as well as the potential influence of metformin use in a meta-analysis of cohort studies.

MATERIALS AND METHODS

Cohort studies investigating the association between DM and survival outcomes of patients with NHL were included by search of electronic databases that included PubMed, Embase, and Web of Science. A random-effects model was adopted to combine the results.

RESULTS

Eight cohort studies including 8652 patients with NHL were analyzed. Compared to non-DM patients with NHL, DM was associated with poor overall survival (OS, hazard ratio [HR] = 1.49, 95% confidence interval [CI]: 1.18-1.89, P < .001, I² = 69%), progression-free survival (PFS, HR = 1.30, 95% CI: 1.09-1.56, P = .004, I² = 0%), and lymphoma-specific survival (LSS, HR = 1.86, 95% CI: 1.41-2.45, P < .001, I² = 0%). Subgroup analysis showed consistent results in patients with diffuse large B-cell lymphoma (DLBCL, HR = 1.42, 1.35, and 1.95 for outcomes of OS, PFS, and LSS, respectively; P values all <.05). However, the associations between DM and these survival outcomes became nonsignificant in subgroup analysis limited to DM patients with concurrent use of metformin (HR = 1.30, 1.12, and 1.43 for outcomes of OS, PFS, and LSS, respectively; P values all > .10).

CONCLUSIONS

DM is associated with poor survival outcomes in patients with B-cell NHL, which is consistent in patients with DLBCL. Concurrent metformin use in DM patients with NHL may be associated with improved survival outcomes.

Fatty acid synthase and adenosine monophosphate-activated protein kinase regulate cell survival and drug sensitivity in diffuse large B-cell lymphoma

Fatty acid synthesis is crucial in supporting the survival and proliferation of multiple forms of cancer. The high metabolic demands of fatty acid synthesis are regulated by the AMP-activated kinase and activity of the fatty acid synthase enzyme. In this study, the roles of these enzymes in diffuse large B-cell lymphoma (DLBCL) were investigated by genetic knock-down and pharmacological activation of AMP-activated kinase by metformin, and selective inhibition of fatty acid synthase using the novel drug Fasnall. We observed distinct heterogeneity and adaptive plasticity of lipid metabolism in a panel of DLBCL cell lines and demonstrate the therapeutic potential of inhibiting fatty acid synthesis in a subset of DLBCL cells. The translational relevance of these in vitro data is supported by the strong correlation between AMP-activated protein kinase expression in primary DLBCL samples and disease relapse. Inhibition of fatty acid synthase with Fasnall may represent a therapeutic option for DLBCL that preferentially subverts to de novo fatty acid synthesis.

Metformin Associated With Increased Survival in Type 2 Diabetes Patients With Pancreatic Cancer and Lymphoma

BACKGROUND

The biguanide drug metformin is one of the most commonly used medications for the treatment of type 2 diabetes mellitus. Diabetics are at an increased risk for cancer. Previous studies have demonstrated improved outcomes in patients taking metformin suffering from prostate, colon, lung, thyroid, and esophageal cancers. Metformin's main antineoplastic mechanism of action is thought to be mediated through inhibition of mammalian target of rapamycin, inhibition of hypoxia-inducible factor 1 (HIF-1) alpha, and activation of p53. We investigated the overall survival of type 2 diabetic patients on metformin with pancreatic cancer and lymphoma using the Computerized Patient Record System at the Veterans Affairs Medical Center, Memphis TN.

METHODS

Lymphoma and pancreatic cancer patients with type 2 diabetes were sorted into an experimental (metformin) group and a control (nonmetformin) group. Patients were compared on baseline characteristics including race, body mass index, and age. Cancer outcomes including overall survival, metastasis, recurrences, and incidence of new malignancies were recorded. Hemoglobin A1C, creatinine and cancer treatment modalities were recorded and compared. Statistical analyses used included unpaired t tests and Chi-squared tests.

RESULTS

There was significantly greater overall long-term survival in the metformin group compared to the nonmetformin group for lymphoma (5.89 vs 1.29 years, P < 0.001) and for pancreatic cancer (0.68 vs 0.22 years, P = 0.016). Cancer treatment modalities in both groups were comparable.

CONCLUSIONS

Metformin is associated with a significant, positive effect of increased overall survival in type 2 diabetes patients with pancreatic cancer and lymphoma. These results are encouraging, and prospective studies should be done to further investigate metformin's effects in cancer.

Impact of metformin use on the outcomes of newly diagnosed diffuse large B-cell lymphoma and follicular lymphoma

The diabetes mellitus (DM) drug metformin targets mechanistic/mammalian target of rapamycin and inhibits lymphoma growth in vitro. We investigated whether metformin affected outcomes of newly diagnosed diffuse large B-cell (DLBCL, n = 869) and follicular lymphoma (FL, n = 895) patients enrolled in the Mayo component of the Molecular Epidemiology Resource cohort study between 2002 and 2015. Hazard ratios (HR) and 95% confidence intervals (CIs) adjusted for age, sex, body mass index, prognostic index and treatment were used to estimate the association of metformin exposure (No DM/No metformin; DM/No metformin; DM/Metformin) with event-free (EFS), lymphoma-specific (LSS) and overall (OS) survival. Compared to No DM/No metformin DLBCL patients, there was no association of DM/Metformin (n = 48; HR = 1·05, 95% CI 0·59-1·89) or DM/No metformin(n = 54; HR = 1·41, 95% CI 0·88-2·26) with EFS; results were similar for LSS and OS. Compared to No DM/No metformin FL patients, there was no association of DM/Metformin (n = 37; HR = 1·16, 95% CI 0·71-1·89) or DM/No metformin (n = 19; HR = 1·16, 95% CI 0·66-2·04) with EFS; results were similar for LSS. However, DM/Metformin was associated with inferior OS (HR = 2·17; 95% CI 1·19-3·95) compared to No DM/No metformin. In conclusion, we found no evidence that metformin use was associated with improved outcomes in newly diagnosed DLBCL and FL.

Metabolic Reprogramming of Non-Hodgkin's B-Cell Lymphomas and Potential Therapeutic Strategies

Metabolism is a wide and general term that refers to any intracellular pathways the cell utilizes in order to satisfy its energetic demand and to support cell viability and/or division. Along with phenotypic changes, all mammalian cells including immune cells modulate their metabolic program in order to reach their effector functions. Exacerbated metabolism and metabolic flexibility are also hallmarks of tumor initiation and of tumor cell progression in a complex tumor microenvironment. Metabolic reprogramming is mainly directed by the serine/threonine kinase mTOR (mammalian target of rapamycin). mTOR exists in two structurally and functionally distinct complexes, mTORC1 and mTORC2 that coordinate environmental signals and metabolic/anabolic pathways to provide macromolecules and energy needed for survival and growth. Activation of mTORC1 is required during development, differentiation and activation of immune cells. Aberrant and persistent activation of mTORC1 is often observed in malignant B cells such as Non-Hodgkin's (NH) B-cell lymphomas. Here, we review recent insights on cell metabolism and on basic mechanisms of mTORC1 regulation and metabolic functions. We highlight the distinct mechanisms driving mTORC1 activation in the three most-common types of NH B-cell lymphomas (Diffuse Large B Cell Lymphomas, Follicular Lymphomas, and Mantle Cell Lymphomas), for which the first generation of mTORC1 inhibitors (rapalogs) have been extensively evaluated in preclinical and clinical settings. Finally, we discuss the reasons for limited clinical success of this therapy and focus on potential therapeutic strategies targeting metabolic pathways, upstream and downstream of mTORC1, that can be combined to rapalogs in order to improve patient's outcome.

Metformin and Autoimmunity: A "New Deal" of an Old Drug

Metformin (dimethyl biguanide) is a synthetic derivative of guanidine, isolated from the extracts of Galega officinalis, a plant with a prominent antidiabetic effect. Since its discovery more than 50 years ago, metformin represents a worldwide milestone in treatment of patients with type 2 diabetes (T2D). Recent evidence in humans indicates novel pleiotropic actions of metformin which span from its consolidated role in T2D management up to various regulatory properties, including cardio- and nephro-protection, as well as antiproliferative, antifibrotic, and antioxidant effects. These findings, together with ground-breaking studies demonstrating its ability to prolong healthspan and lifespan in mice, provided the basis for defining metformin as a potential antiaging molecule. Moreover, emerging in vivo and in vitro evidence support the novel hypothesis that metformin can exhibit immune-modulatory features. Studies suggest that metformin interferes with key immunopathological mechanisms involved in systemic autoimmune diseases, such as the T helper 17/regulatory T cell balance, germinal centers formation, autoantibodies production, macrophage polarization, cytokine synthesis, neutrophil extracellular traps release, and bone or extracellular matrix remodeling. These effects may represent a powerful contributor to antiaging and anticancer properties exerted by metformin and, from another standpoint, may open the way to assess whether metformin can be a candidate molecule for clinical trials involving patients with immune-mediated diseases. In this article, we will review the available preclinical and clinical evidence regarding the effect of metformin on individual cells of the immune system, with emphasis on immunological mechanisms related to the development and maintenance of autoimmunity and its potential relevance in treatment of autoimmune diseases.

Mitochondrial and glycolytic metabolic compartmentalization in diffuse large B-cell lymphoma

Metabolic heterogeneity between neoplastic cells and surrounding stroma has been described in several epithelial malignancies; however, the metabolic phenotypes of neoplastic lymphocytes and neighboring stroma in diffuse large B-cell lymphoma (DLBCL) is unknown. We investigated the metabolic phenotypes of human DLBCL tumors by using immunohistochemical markers of glycolytic and mitochondrial oxidative phosphorylation (OXPHOS) metabolism. The lactate importer MCT4 is a marker of glycolysis, whereas the lactate importer MCT1 and TOMM20 are markers of OXPHOS metabolism. Staining patterns were assessed in 33 DLBCL samples as well as 18 control samples (non-neoplastic lymph nodes). TOMM20 and MCT1 were highly expressed in neoplastic lymphocytes, indicating an OXPHOS phenotype, whereas non-neoplastic lymphocytes in the control samples did not express these markers. Stromal cells in DLBCL samples strongly expressed MCT4, displaying a glycolytic phenotype, a feature not seen in stromal elements of non-neoplastic lymphatic tissue. Furthermore, the differential expression of lactate exporters (MCT4) on tumor-associated stroma and lactate importers (MCT1) on neoplastic lymphocytes support the hypothesis that neoplastic cells are metabolically linked to the stroma likely via mutually beneficial reprogramming. MCT4 is a marker of tumor-associated stroma in neoplastic tissue. Our findings suggest that disruption of neoplastic-stromal cell metabolic heterogeneity including MCT1 and MCT4 blockade should be studied to determine if it could represent a novel treatment target in DLBCL.