Effect of Exposure to Agent Orange on the Risk of Monoclonal Gammopathy and Subsequent Transformation to Multiple Myeloma: A Single-Center Experience From the Veterans Affairs Hospital, Detroit

The Association of Agent Orange Exposure with the progression of monoclonal gammopathy of undetermined significance to multiple myeloma: a population-based study of Vietnam War Era Veterans

Herbicide and pesticide exposure [e.g., agent orange (AO)] is associated with an increased risk of multiple myeloma (MM) due to the contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, it is unclear whether TCDD/AO exposure (AO exposure hereafter) increases the risk of progression of monoclonal gammopathy of undetermined significance (MGUS) to MM. We sought to evaluate the association in a nationwide study of US Veterans. A natural language processing algorithm was used to confirm MGUS and progression to MM. We included Veterans who were diagnosed with MGUS from 10/1/1999 to 12/31/2021 and served during the Vietnam War Era from 1/9/1962 to 5/7/1975. AO exposure was stratified according to three TCDD exposure levels: high (1/9/1962-11/30/1965), medium (12/1/1965-12/31/1970), or low (1/1/1971-5/7/1975). The association between AO exposure and progression was analyzed using multivariable Fine-Gray subdistribution hazard model with death as a competing event. The analytic cohort included 10,847 Veterans with MGUS, of whom 26.3% had AO exposure and 7.4% progressed to MM over a median follow-up of 5.2 years. In multivariable analysis, high exposure was associated with an increased progression rate (multivariable-adjusted hazard ratio 1.48; 95% confidence interval 1.02-2.16), compared to Veterans with no exposure. This information is critical to inform progression risk in patients diagnosed with MGUS and prior AO exposure. It is also applicable to MGUS patients with occupational TCDD exposure from herbicides and pesticides.

The Clinical Relevance of Selected Cytokines in Newly Diagnosed Multiple Myeloma Patients

Multiple myeloma (MM) is the second most common hematological neoplasm. Cytokines, chemokines, and their receptors, induced by the microenvironment of MM, participate in tumor growth, the attraction of leukocytes, cell homing, and bone destruction. This study aimed to assess the correlation between the pretreatment serum concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), angiogenic chemokine monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor (VEGF) and the clinical outcomes and survival of patients newly diagnosed with MM. The study group consisted of 82 individuals. The IL-8 concentration was significantly positively correlated with the age of onset (p = 0.007), the International Staging System (ISS) stage (p = 0.03), the Eastern Cooperative Oncology Group (ECOG) performance status (p < 0.001), the degree of anemia before treatment (p < 0.0001), the degree of kidney disease (p < 0.001), and VEGF (p = 0.0364). Chemotherapy responders had significantly lower concentrations of IL-8 (p < 0.001), IL-6 (p < 0.001), and VEGF (p = 0.04) compared with non-responders. Patients with treatment-induced polyneuropathy had significantly higher levels of IL-8 (p = 0.033). Patients with a high level of IL-6 had a 2-fold higher risk of progression-free survival (PFS) reduction (17 vs. 35 months; HR = 1.89; p = 0.0078), and a more than 2.5-fold higher risk of overall survival (OS) reduction (28 vs. 78 months; HR = 2.62; p < 0.001). High levels of IL-6, IL-8, and VEGF demonstrated significant predictive values for some clinical conditions or outcomes of newly diagnosed MM patients. Patients with an early response to chemotherapy had a significantly lower concentration of these cytokines. A high pretreatment IL-6 concentration was an independent negative prognostic marker for newly diagnosed MM patients.

The Association of Agent Orange (AO) Exposure with Monoclonal Gammopathy of Undetermined Significance (MGUS) to Multiple Myeloma (MM) Progression: A Population-based Study of Vietnam War Era Veterans

Background

Herbicide and pesticide exposure (e.g., agent orange [AO]) is associated with an increased risk of multiple myeloma (MM) due to the contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Monoclonal gammopathy of undetermined significance (MGUS) is the precursor state to MM; however, not all patients with MGUS progress to MM. It is unclear whether AO exposure increases the risk of progression of MGUS to MM.

Purpose

We aimed to determine the association between AO exposure and progression to MM in a nation-wide study of U.S. Veterans with MGUS.

Patients and Methods

This is a population-based cohort study of Vietnam Era Veterans diagnosed with MGUS. A natural language processing (NLP) algorithm was used to confirm MGUS and progression to MM. The association between AO and progression was analyzed using multivariable Fine-Gray subdistribution hazard model with death as a competing event. Veterans who served during the Vietnam War Era from 1/9/1962-5/7/1975 and were diagnosed with MGUS between 10/1/1999-12/31/2021 were included. We excluded patients with missing BMI values, progression within 1 year after MGUS diagnosis date, non-IgG or IgA MGUS, or birth years outside of the range of the AO exposed group, and race other than Black and White. AO exposure and service during 1/9/1962-;5/7/1975 and stratified according to TCDD exposure levels by three time periods: 1/9/1962-11/30/1965 (high), 12/1/1965-12/31/1970 (medium), or 1/1/1971-5/7/1975 (low). The association between AO and progression was analyzed using multivariable Fine-Gray subdistribution hazard model with death as a competing event.

Results

We identified 10,847 Veterans with MGUS, of whom 7,996 had AO exposure. Overall, 7.4% of MGUS patients progressed to MM over a median follow-up of 5.2 years. In multivariable analysis, AO exposure from 1/9/1962-11/30/1965, high TCDD exposure, was associated with an increased risk of progression (adjusted hazard ratio 1.48; 95% confidence interval 1.02-2.16), compared to Veterans with no exposure.

Conclusions

In patients with MGUS, the high Agent Orange exposure time period is associated with a 48% increased risk of progression to multiple myeloma. This suggests that patients with MGUS and prior Agent Orange exposure or occupational exposure to TCDD (eg. Agricultural workers) may require thorough screening for plasma cell dyscrasias.

Updates in the management of relapsed/refractory multiple myeloma

Multiple myeloma, a malignant neoplasm of plasma cells that accumulate in bone marrow, accounts for approximately 18% of hematologic malignancies in the United States. Patients are often treated with triplet therapy and may undergo stem cell transplantation. Despite effective therapies, multiple myeloma remains incurable. Patients often require maintenance therapy, and many will progress or relapsed following upfront treatment. Selection of treatment in the relapse/refractory setting is complex due numerous active therapeutic agents and combinations. Treatment is often tailored to prior exposure and duration. In 2020, three novel pharmacological agents were approved in the relapsed setting. We highlight the clinical safety and efficacy of selinexor, isatuximab-irfc, and belantamab mafodotin for patients with multiple myeloma.