Multiple myeloma (MM) is a cancer of plasma cells in the bone marrow. It is one of the qualifying diagnoses our team evaluates for Roundup litigation, and it is one of the cancers with the strongest agricultural-exposure literature behind it. This guide walks through what multiple myeloma is, how it gets diagnosed, the glyphosate-MM evidence base, the modern treatment landscape, and what plasma cell cancer cases require to move forward.
What Multiple Myeloma Is
Plasma cells are the antibody-producing arm of the immune system. They are mature B lymphocytes that have differentiated to manufacture immunoglobulins. In multiple myeloma, plasma cells in the bone marrow become malignant, multiply uncontrollably, and produce abnormal monoclonal antibodies (M-proteins) that accumulate in the blood and urine.
Multiple myeloma is classified within the family of plasma cell dyscrasias. The disease typically progresses through a spectrum:
- Monoclonal gammopathy of undetermined significance (MGUS). A precursor condition in which an M-protein is present without organ damage. About 1% of MGUS patients per year progress to multiple myeloma. MGUS itself is not cancer.
- Smoldering multiple myeloma. An intermediate stage with higher M-protein levels and bone marrow plasma cell percentages but still without organ damage. Higher annual progression risk to active myeloma.
- Active multiple myeloma. The clinical diagnosis requiring treatment. Defined by meeting the CRAB criteria or by certain biomarker thresholds.
Multiple myeloma represents approximately 1.8% of all cancer diagnoses in the United States and approximately 2% of cancer deaths. The American Cancer Society projects roughly 35,000 new cases per year. The median age at diagnosis is in the late 60s.
The CRAB Criteria — What Defines Active Disease
The diagnosis of active multiple myeloma requires evidence of organ damage attributable to the underlying plasma cell disorder. The classic CRAB criteria:
- C — Calcium elevated (serum calcium > 11 mg/dL or > 1 mg/dL above upper limit of normal). The malignant plasma cells release factors that activate osteoclasts and break down bone, releasing calcium into the blood.
- R — Renal insufficiency (creatinine > 2 mg/dL or creatinine clearance < 40 mL/min). The light chains produced by the malignant plasma cells deposit in the kidneys and cause cast nephropathy, sometimes leading to dialysis dependence.
- A — Anemia (hemoglobin < 10 g/dL or > 2 g/dL below the lower limit of normal). The bone marrow becomes infiltrated with malignant plasma cells, crowding out normal red cell production.
- B — Bone lesions (one or more osteolytic lesions on imaging). Lytic destruction of vertebral bodies, ribs, skull, pelvis, and long bones produces fractures, severe back pain, and spinal cord compression in advanced disease.
Updated International Myeloma Working Group criteria added several biomarker thresholds (clonal bone marrow plasma cell percentage ≥ 60%, serum free light chain ratio ≥ 100, > 1 focal lesion on MRI) that allow diagnosis even when the CRAB criteria are not yet present, when those biomarkers indicate inevitable progression to symptomatic disease.
How Multiple Myeloma Gets Diagnosed
The diagnostic workup typically begins when a patient presents with one of the cardinal symptoms — severe back pain (from vertebral lesions), fatigue (from anemia), recurrent infections (from immunoglobulin dysregulation), kidney problems, or hypercalcemia. The workup then includes:
- Serum protein electrophoresis (SPEP) and immunofixation — identifying the monoclonal M-protein and characterizing the immunoglobulin class (IgG, IgA, light chain only, IgD, IgM, biclonal).
- Urine protein electrophoresis (UPEP) and 24-hour urine collection — identifying Bence Jones proteins (free light chains in the urine).
- Serum free light chain assay — measuring kappa and lambda light chains and the kappa/lambda ratio.
- Bone marrow biopsy and aspirate — documenting the clonal plasma cell percentage (≥ 10% is the standard threshold for myeloma; < 10% with M-protein suggests MGUS or smoldering).
- Cytogenetics and FISH on bone marrow plasma cells — identifying prognostic chromosomal abnormalities (t(4;14), t(14;16), del(17p), 1q21 gain/amplification, and others).
- Imaging — whole-body low-dose CT, PET-CT, or whole-body MRI is the modern standard, replacing the older skeletal survey for identifying lytic bone lesions.
The Glyphosate-Multiple Myeloma Evidence Base
Multiple myeloma has been studied in agricultural worker populations for decades. The exposure-MM literature includes:
- The Agricultural Health Study (AHS). A prospective cohort study of approximately 89,000 pesticide applicators and their spouses in Iowa and North Carolina, ongoing since 1993, run by the National Cancer Institute, the National Institute of Environmental Health Sciences, and the EPA. Several AHS analyses have examined the glyphosate-MM relationship; the 2018 update (De Roos et al., JNCI) found suggestive but not statistically significant elevations in multiple myeloma risk among the highest-exposure quartile of applicators.
- IARC Monograph 112 (2015). The International Agency for Research on Cancer’s classification of glyphosate as Group 2A "probably carcinogenic to humans" was based primarily on NHL evidence but the monograph also reviewed multiple myeloma data and noted positive but inconsistent findings.
- Meta-analyses. Multiple meta-analyses of agricultural pesticide exposure and multiple myeloma have found elevated relative risks for agricultural worker populations, with glyphosate among the implicated exposures.
- Mechanistic plausibility. Glyphosate has been shown to cause oxidative DNA damage, induce chromosomal aberrations, and disrupt immune function — mechanisms consistent with multiple myeloma pathogenesis from the MGUS precursor state through symptomatic disease.
The defense often emphasizes that the multiple myeloma evidence is less robust than the NHL evidence base on which most Roundup verdicts have rested. The plaintiff response cites the consistent agricultural-exposure signal across multiple studies, the biological mechanism applicable across B-cell lineage malignancies, the EPA’s own historical recognition of pesticide-MM associations, and the inclusion of MM within the qualifying diagnosis frameworks adopted in the federal MDL.
The Modern Treatment Landscape
Multiple myeloma is a treatable but generally not curable disease. The therapeutic landscape has changed dramatically over the past 25 years, with median overall survival roughly doubling. The modern treatment paradigm:
Induction therapy
Most patients receive a triplet or quadruplet induction regimen combining a proteasome inhibitor (bortezomib, carfilzomib, or ixazomib), an immunomodulatory drug (lenalidomide or thalidomide), an anti-CD38 monoclonal antibody (daratumumab or isatuximab), and dexamethasone. Common regimens include VRd, KRd, D-VRd, and D-KRd.
Autologous stem cell transplant
Eligible patients (typically those under 75 with adequate organ function) proceed to autologous stem cell transplant after induction. Stem cells are harvested, the patient receives high-dose melphalan, and the stem cells are reinfused. Transplant is consolidative; it does not cure.
Maintenance therapy
Lenalidomide maintenance is the standard post-transplant approach, typically continued indefinitely until progression or intolerance.
Relapsed/refractory disease
Most patients eventually relapse. The relapsed/refractory armamentarium has expanded substantially: pomalidomide, elotuzumab, selinexor, venetoclax (for t(11;14) myeloma), bispecific antibodies (teclistamab, talquetamab, elranatamab), and CAR-T cell therapy targeting BCMA (idecabtagene vicleucel, ciltacabtagene autoleucel). Sequencing of these therapies is an active area of clinical research.
What Multiple Myeloma Roundup Cases Require
To evaluate a multiple myeloma case our team typically asks about:
- The diagnosis records. SPEP/UPEP, serum free light chain results, bone marrow biopsy report, cytogenetics, imaging studies showing the bone lesions or biomarker thresholds. The diagnosis date and the criteria met at that date matter for timing.
- The exposure history. Years of glyphosate use, application frequency, products used (Roundup branded and generic glyphosate formulations), application method (handheld sprayer, backpack sprayer, boom sprayer, granular spreader), personal protective equipment used, agricultural or non-agricultural setting.
- Treatment records. Induction regimen, transplant if performed, maintenance therapy, lines of therapy in relapsed disease, current disease status, performance status.
- Damages picture. Past and future medical care (induction, transplant, maintenance, relapsed-disease therapy, supportive care for bone disease, dialysis if kidney involvement), lost wages and earning capacity if employment was affected, pain and suffering, loss of enjoyment of life, and wrongful death/survival damages if the disease was fatal.
- Filing window analysis. The personal injury statute of limitations applicable in the state where the case is filed, with discovery-rule analysis if the connection between the exposure and the disease was not apparent at the time of diagnosis.
How a Chronic, Treatable-but-Not-Curable Cancer Shapes the Damages Picture
Multiple myeloma is different from lymphomas like DLBCL that aim for cure with R-CHOP. The standard expectation is that the patient will remain on therapy in some form for the rest of life. That fact carries through to the damages picture:
- Lifetime expected medical costs are typically substantial — induction, transplant, ongoing maintenance, relapsed-disease care, and supportive care for bone disease and renal complications.
- The arc of the disease — remission, progression, second-line therapy, second remission, second progression — produces an episodic-deterioration pattern that life care planners model in detail.
- Vocational and quality-of-life damages are typically substantial; many patients are unable to return to physically demanding work even in deep remission.
- Wrongful death cases often emerge years after diagnosis; the survival-action component for the period of life with the disease typically dominates the recovery.
If You or a Family Member Has Been Diagnosed
Free case review for multiple myeloma plaintiffs and surviving families.
- Read about the broader case framework: Multiple Myeloma Roundup Lawsuit Overview.
- Read about agricultural-worker cases: Farmworkers, Agricultural Workers, and Roundup.
- Read about landscaper and groundskeeper cases: Glyphosate Exposure for Landscapers.
- Read about CLL cases: CLL and Roundup.
- Read about DLBCL cases: DLBCL and Roundup.
Free case review. No fees unless we recover compensation for you.
Sources
- International Agency for Research on Cancer (IARC) — Monograph 112 on glyphosate. iarc.who.int
- National Cancer Institute — Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment (PDQ). cancer.gov
- American Cancer Society — Key Statistics About Multiple Myeloma. cancer.org
- International Myeloma Working Group — Diagnostic criteria. myeloma.org
- Agricultural Health Study — NIH cohort study of pesticide applicators. aghealth.nih.gov
- De Roos AJ et al. — "Glyphosate Use and Cancer Incidence in the Agricultural Health Study." Journal of the National Cancer Institute, 2018. ncbi.nlm.nih.gov
- American Society of Hematology — Multiple myeloma clinical guidance. hematology.org
- Leukemia & Lymphoma Society — Multiple myeloma patient information. lls.org/myeloma