Multiple Myeloma Medical Services in China

Multiple myeloma (MM) is a malignant plasma cell disorder characterized by the uncontrolled proliferation of clonal plasma cells within the bone marrow. These abnormal cells produce monoclonal immunoglobulins (M-proteins) or free light chains, leading to end-organ damage—commonly summarized by the CRAB criteria: hyperCalcemia, Renal insufficiency, Anemia, and Bone lesions (e.g., lytic lesions, osteoporosis, pathologic fractures). Pathogenesis involves progressive genetic alterations—including translocations involving the immunoglobulin heavy chain locus (e.g., t(11;14), t(4;14)), deletions (e.g., del(17p)), and mutations in genes such as KRAS, NRAS, BRAF, and TP53—that drive dysregulated cell survival, proliferation, and evasion of apoptosis. The bone marrow microenvironment plays a critical role, with cytokines like IL-6, BAFF, and APRIL promoting myeloma cell growth and drug resistance. Epidemiologically, MM accounts for approximately 10% of all hematologic malignancies and 1–2% of all cancers globally. Incidence rises sharply with age, with a median diagnosis age of 69 years; it is rare under age 40. In China, age-standardized incidence is estimated at 1.0–1.3 per 100,000 person-years, with slightly higher rates in males than females. Known risk factors include monoclonal gammopathy of undetermined significance (MGUS)—a precursor condition present in >90% of MM cases—as well as advancing age, male sex, African ancestry (2–3× higher incidence vs. Asian or Caucasian populations), obesity, and occupational exposure to radiation or certain chemicals (e.g., benzene, pesticides). Family history also confers modest increased risk. Quality of life (QoL) is profoundly impacted: chronic bone pain, fatigue from anemia, recurrent infections due to immunoparesis, renal dysfunction requiring dialysis, and treatment-related toxicities (e.g., peripheral neuropathy, cytopenias, cognitive changes) contribute to physical disability, emotional distress, social withdrawal, and reduced functional independence. Patients often experience anxiety about disease progression and treatment burden, especially during prolonged maintenance therapy. Early diagnosis remains challenging due to nonspecific symptoms—such as fatigue, back pain, or recurrent sinusitis—which may delay referral to hematology. With modern therapies—including proteasome inhibitors (bortezomib, carfilzomib), immunomodulatory drugs (lenalidomide, pomalidomide), monoclonal antibodies (daratumumab, isatuximab), and emerging BCMA-targeted agents (bispecific antibodies, CAR-T cells)—median overall survival has improved to 7–10 years in fit patients, though outcomes vary significantly by cytogenetic risk, access to novel agents, and supportive care infrastructure.

Multiple myeloma (MM) is a clonal plasma cell malignancy characterized by the uncontrolled proliferation of terminally differentiated B lymphocytes in the bone marrow, leading to end-organ damage—including hypercalcemia, renal insufficiency, anemia, and bone lesions (CRAB criteria). Despite extensive research, the precise etiology remains incompletely understood; MM is considered a multistep oncogenic process arising from precursor conditions such as monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). There are no definitive exogenous 'causes' in the traditional sense—no single infectious agent, toxin, or behavior directly causes MM—but rather a constellation of interrelated genetic, epigenetic, immunologic, and environmental factors that collectively drive malignant transformation and clonal evolution.

Genetic factors play a central role. Nearly all MM cases harbor recurrent somatic mutations and chromosomal aberrations. Primary immunoglobulin heavy chain (IGH) translocations—particularly t(11;14), t(4;14), t(14;16), and t(14;20)—occur early during B-cell development and dysregulate oncogenes (e.g., CCND1, FGFR3/MMSET, MAF, MAFB). Hyperdiploidy (gain of odd-numbered chromosomes) defines another major molecular subgroup. Secondary genomic events accumulate over time, including mutations in KRAS, NRAS, BRAF, TP53, DIS3, FAM46C, and TRAF3, as well as deletions of chromosome 17p (encompassing TP53) and 13q, which confer adverse prognosis. Germline predisposition also contributes: genome-wide association studies (GWAS) have identified polymorphisms in genes involved in immune regulation (e.g., ULBP3, CDCA7L, TNFRSF13B), DNA repair (e.g., PARP1), and telomere maintenance (e.g., TERT), suggesting inherited susceptibility modulates risk. Familial clustering occurs in ~3–5% of cases, with first-degree relatives exhibiting a 2- to 4-fold increased risk.

Environmental and occupational exposures are implicated but inconsistently validated. Ionizing radiation is the most robustly associated environmental risk factor—survivors of atomic bomb explosions and patients exposed to therapeutic radiation show elevated MM incidence. Chronic antigenic stimulation may contribute: epidemiologic studies report modest associations with autoimmune disorders (e.g., rheumatoid arthritis, pernicious anemia), chronic infections (e.g., hepatitis C, HIV), and certain vaccinations (though causality remains unproven). Occupational exposure to agricultural chemicals—including organochlorine pesticides (e.g., DDT), herbicides (e.g., phenoxyacetic acids), and solvents—has been linked to increased risk in meta-analyses, likely via oxidative stress and DNA damage. Similarly, prolonged exposure to benzene and petroleum derivatives among firefighters, painters, and refinery workers shows elevated odds ratios. Obesity is a consistently replicated modifiable risk factor; adipose tissue promotes chronic inflammation, insulin resistance, and secretion of cytokines (e.g., IL-6, VEGF, leptin) that support plasma cell survival and bone marrow angiogenesis. Physical inactivity and diets high in processed meats and saturated fats further amplify this pro-inflammatory milieu.

Demographic and clinical risk factors include advancing age (median diagnosis at 69 years), male sex (1.5-fold higher incidence than females), and Black race (2–3 times higher incidence compared with White populations—attributed to both genetic ancestry-related variants and socioeconomic disparities affecting healthcare access and environmental exposures). Prior history of MGUS or SMM confers annual progression risks of ~1% and ~10%, respectively. Immunosuppression—whether iatrogenic (e.g., post-transplant regimens) or disease-related (e.g., common variable immunodeficiency)—may impair immune surveillance against emerging malignant clones. Chronic kidney disease and persistent monoclonal proteinemia also correlate with increased risk, reflecting underlying dysregulated B-cell homeostasis.

Importantly, no single trigger initiates MM; rather, cumulative genomic instability, microenvironmental dysregulation (e.g., aberrant NF-κB signaling, bone marrow stromal cell crosstalk), and immune evasion mechanisms converge over decades to permit clonal expansion. While prevention strategies remain elusive, risk stratification incorporating cytogenetics, serum biomarkers (e.g., free light chain ratio, LDH), and imaging-based bone assessment enables earlier intervention in high-risk SMM. Ongoing research focuses on targeting premalignant niches, modulating the tumor microenvironment, and leveraging polygenic risk scores for personalized surveillance.

Multiple myeloma (MM) is a clonal plasma cell malignancy characterized by the uncontrolled proliferation of abnormal plasma cells within the bone marrow, leading to end-organ damage classically summarized by the CRAB criteria: hyperCalcemia, Renal insufficiency, Anemia, and Bone lesions. As a hematologic neoplasm managed primarily by hematology/oncology services, MM often presents insidiously, with early symptoms frequently nonspecific and easily attributed to aging or comorbid conditions.

Early symptoms are typically subtle and may persist for months before diagnosis. Fatigue—often profound and disproportionate to exertion—is the most common initial complaint, primarily attributable to anemia resulting from bone marrow infiltration and cytokine-mediated suppression of erythropoiesis. Patients may report diminished exercise tolerance, lightheadedness on standing, or pallor. Mild, persistent bone pain—especially in the axial skeleton (lower back, thoracic spine, pelvis, or ribs)—may be dismissed as mechanical strain or degenerative arthritis. Recurrent or unusually severe upper respiratory infections (e.g., sinusitis, bronchitis, pneumonia) reflect impaired humoral immunity due to suppression of normal immunoglobulin production (hypogammaglobulinemia) and dysfunctional B-cell help. Unexplained weight loss (>10% body weight over 6 months), low-grade fevers, or night sweats—collectively termed 'B symptoms'—occur less frequently in MM than in lymphomas but may signal high tumor burden or aggressive disease biology.

Typical symptoms emerge as tumor burden increases and end-organ damage becomes evident. Skeletal-related events dominate the clinical picture: >80% of patients develop osteolytic lesions visible on skeletal survey or CT; these manifest as localized, deep, boring bone pain exacerbated by movement or weight-bearing, and may precipitate pathologic fractures—most commonly vertebral compression fractures causing acute back pain, height loss, or kyphosis. Hypercalcemia (serum calcium >11.5 mg/dL) results from osteoclast activation mediated by RANKL, MIP-1α, and other myeloma-secreted factors; it presents with nausea, vomiting, constipation, polyuria, polydipsia, confusion, lethargy, and, in severe cases, altered mental status or cardiac arrhythmias. Renal impairment—often termed myeloma kidney—arises from proximal tubular toxicity by filtered free light chains (cast nephropathy), hypercalcemia-induced nephrocalcinosis, or amyloid deposition; patients may exhibit oliguria, edema, elevated serum creatinine, or overt renal failure. Anemia—typically normocytic, normochromic—is present in ~70% at diagnosis and correlates with disease burden; symptoms include dyspnea on exertion, tachycardia, and cognitive slowing. Hyperviscosity syndrome, though rare (<5%), occurs with very high IgA or IgM paraproteins and manifests as headache, blurred vision, epistaxis, retinal vein engorgement, or neurologic deficits.

Accompanying symptoms reflect systemic inflammation and immune dysregulation. Neuropathies—both peripheral (sensory > motor, stocking-glove distribution) and autonomic—are common, driven by direct nerve infiltration, paraprotein-mediated demyelination (e.g., anti-MAG antibodies in IgM MGUS), or treatment toxicity (e.g., bortezomib). Patients may report paresthesias, numbness, or orthostatic hypotension. Increased susceptibility to encapsulated organisms (Streptococcus pneumoniae, Haemophilus influenzae) stems from quantitative and functional immunoglobulin deficiency. Amyloidosis (AL type) may cause restrictive cardiomyopathy (heart failure, arrhythmias), nephrotic syndrome (proteinuria, hypoalbuminemia, edema), macroglossia, or carpal tunnel syndrome. Cryoglobulinemia (especially with IgM or IgG3) can induce Raynaud phenomenon, purpura, or digital ischemia.

Complications significantly impact morbidity and mortality. Spinal cord compression—due to vertebral collapse or epidural plasmacytoma—presents with radicular pain, motor weakness, sensory loss, or bowel/bladder dysfunction and constitutes an oncologic emergency. Hyperviscosity syndrome may progress to stroke or myocardial infarction. Infection remains the leading cause of death, particularly pneumonia and sepsis. Thromboembolic events (deep vein thrombosis, pulmonary embolism) are heightened by immobility, corticosteroid use, and prothrombotic cytokines. Secondary malignancies—including therapy-related myeloid neoplasms (t-MN) and solid tumors—occur at increased frequency post-autologous stem cell transplant or prolonged lenalidomide exposure. Renal failure may necessitate dialysis; while reversible in some cases with rapid light-chain reduction, chronic kidney disease often persists.

Diagnosis requires integration of clinical, laboratory, and imaging findings per IMWG (International Myeloma Working Group) criteria. Serum and urine protein electrophoresis (SPEP/UPEP) with immunofixation detect and characterize monoclonal proteins (M-proteins); serum free light chain (sFLC) assay quantifies involved/uninvolved kappa/lambda ratios—abnormal ratio (<0.01 or >100) plus involved FLC ≥100 mg/L supports diagnosis. Bone marrow aspiration and biopsy must demonstrate ≥10% clonal plasma cells (or any percentage with clonality confirmed by flow cytometry or molecular studies); immunohistochemistry (CD138, CD38) and flow cytometry (CD38+, CD138+, CD56+, CD19−, CD45−, cytoplasmic light chain restriction) confirm clonality. Imaging is mandatory: low-dose whole-body CT, PET/CT, or whole-body MRI detects lytic lesions, extramedullary disease, or diffuse infiltration not apparent on plain radiographs. CRAB features or myeloma-defining events (MDEs)—including clonal bone marrow plasma cells ≥60%, serum FLC ratio ≥100 (with involved FLC ≥100 mg/L), or >1 focal lesion on MRI—confirm active disease requiring treatment.

Differential diagnosis includes monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), Waldenström macroglobulinemia (WM), AL amyloidosis, POEMS syndrome, plasma cell leukemia, and metastatic carcinoma. MGUS and SMM lack CRAB features or MDEs and show lower M-protein levels (<3 g/dL and <30% plasma cells, respectively). WM is distinguished by lymphoplasmacytic infiltration, IgM paraprotein, MYD88 L265P mutation, and absence of lytic bone disease. AL amyloidosis may mimic MM but typically shows low tumor burden, dominant organ involvement (cardiac, renal), and absence of significant bone lesions. POEMS syndrome features polyneuropathy, organomegaly, endocrinopathy, M-protein (usually lambda), and skin changes, with elevated VEGF. Plasma cell leukemia presents with ≥20% plasma cells in peripheral blood or absolute count ≥2×10⁹/L. Metastatic disease may simulate lytic lesions but lacks monoclonal protein, bone marrow plasmacytosis, or light-chain restriction. Accurate distinction guides prognosis and therapeutic strategy.

Multiple myeloma (MM) is a clonal plasma cell malignancy characterized by the proliferation of abnormal plasma cells in the bone marrow, leading to end-organ damage—including hypercalcemia, renal insufficiency, anemia, and bone lesions (CRAB criteria). As a hematologic malignancy managed primarily within hematology departments, MM requires a multidisciplinary, risk-adapted therapeutic strategy. Treatment goals include disease control, symptom alleviation, preservation of organ function, delay of progression, and—increasingly—achievement of deep, sustained remission or functional cure.

Conservative management forms the cornerstone of supportive care and remains essential throughout the disease continuum. This includes vigilant monitoring of renal function with hydration and avoidance of nephrotoxic agents (e.g., NSAIDs, IV contrast), prompt correction of hypercalcemia via intravenous saline hydration and bisphosphonates (e.g., zoledronic acid or denosumab), and management of anemia with erythropoiesis-stimulating agents (ESAs) or transfusions when indicated. Skeletal-related events are mitigated through routine skeletal surveys or low-dose whole-body CT/MRI, along with prophylactic radiation for impending pathologic fractures and orthopedic stabilization for lytic lesions causing mechanical instability. Infection prevention is critical: patients receive pneumococcal and influenza vaccinations, and long-term antimicrobial prophylaxis (e.g., trimethoprim-sulfamethoxazole) is recommended during immunosuppressive therapy. Nutritional support, physical rehabilitation, and psychosocial counseling further optimize quality of life and treatment tolerance.

Pharmacotherapy constitutes the primary disease-modifying intervention. First-line regimens for transplant-eligible patients typically consist of triplet combinations: bortezomib (a proteasome inhibitor), lenalidomide (an immunomodulatory drug), and dexamethasone (VRd); or daratumumab (anti-CD38 monoclonal antibody) plus VRd (D-VRd), which has demonstrated superior progression-free survival (PFS) and minimal residual disease (MRD) negativity rates in phase III trials. For transplant-ineligible patients, daratumumab–lenalidomide–dexamethasone (DRd) or lenalidomide–dexamethasone (Rd) with dose adjustments based on age and comorbidities are standard. Maintenance therapy—typically with lenalidomide post-autologous stem cell transplantation (ASCT)—significantly prolongs PFS and overall survival (OS). Relapsed/refractory MM is managed with novel agents including selinexor (XPO1 inhibitor), belantamab mafodotin (BCMA-targeting antibody-drug conjugate), and bispecific T-cell engagers (e.g., teclistamab, elranatamab). Chimeric antigen receptor T-cell (CAR-T) therapies targeting BCMA—such as idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel)—have shown unprecedented response durability in heavily pretreated patients, with median PFS exceeding 30 months in pivotal trials.

Surgical intervention plays a highly selective, palliative role. Orthopedic surgery is indicated for pathologic vertebral compression fractures unresponsive to kyphoplasty/vertebroplasty, unstable long-bone lesions at high risk of fracture, or spinal cord compression requiring decompression and stabilization. Surgical resection of solitary plasmacytomas (extramedullary or osseous) may be curative when complete resection is feasible and systemic disease is excluded. However, surgery is never used for systemic MM control; rather, it serves as adjunctive local therapy to restore mechanical integrity, relieve pain, and prevent neurologic compromise. All surgical candidates undergo thorough preoperative assessment of bone marrow reserve, coagulation status, and infection risk given their immunocompromised state.

China offers distinct advantages in MM care, driven by rapid integration of global innovations alongside domestic research leadership. Over 200 clinical trials for MM—including phase I–III studies of next-generation CAR-Ts (e.g., EMB-06, CT053), BCMA bispecifics, and oral proteasome inhibitors—are actively recruiting across tier-1 academic centers (e.g., Peking University People’s Hospital, Ruijin Hospital Shanghai Jiao Tong University). The National Medical Products Administration (NMPA) has approved daratumumab, ixazomib, and cilta-cel ahead of many peer nations, enabling earlier access to breakthrough therapies. Cost-effectiveness is enhanced through centralized procurement policies and inclusion of key agents (e.g., lenalidomide, bortezomib) in the National Reimbursement Drug List (NRDL), reducing out-of-pocket expenses by up to 70%. Furthermore, China’s robust hematopoietic stem cell transplantation infrastructure—performing over 12,000 ASCTs annually—ensures broad access to this potentially curative modality. Standardized national MM diagnosis and treatment guidelines (CSCO and Chinese Society of Hematology) promote evidence-based, equitable care across urban and provincial centers.

Recovery and long-term survivorship require structured, proactive guidance. Patients should engage in regular, low-impact physical activity (e.g., walking, tai chi) to maintain bone density and muscle strength while minimizing fracture risk. A calcium- and vitamin D–supplemented diet—avoiding excessive animal protein and sodium—is advised to mitigate hypercalcemia and renal stress. Strict adherence to prescribed maintenance therapy and scheduled MRD monitoring (via next-generation flow cytometry or sequencing of bone marrow aspirates every 3–6 months) is critical for early relapse detection. Vaccination schedules must be updated per ASCO/EBMT recommendations—avoiding live vaccines during active immunosuppression but prioritizing pneumococcal conjugate (PCV20), herpes zoster subunit (RZV), and annual influenza vaccines. Psychosocial resilience is fostered through dedicated MM patient advocacy networks (e.g., China Myeloma Foundation), telehealth-enabled symptom tracking apps, and routine screening for depression/anxiety using validated tools (PHQ-9, GAD-7). Finally, fertility preservation counseling should be offered prior to alkylator-based induction or ASCT, particularly for patients under age 45. With evolving therapeutic paradigms, median OS now exceeds 8–10 years for standard-risk MM—and approaches 15 years in select MRD-negative cohorts—underscoring the importance of lifelong, coordinated hematologic follow-up.