Overview of Staging and Classification Systems in Myeloma

Key Takeaways

• Staging measures the aggressiveness of your myeloma.
• Risk stratification predicts how your myeloma might respond to treatment.
• Standard-risk myeloma (~80% of patients) typically responds well to treatment.
• High-risk myeloma (~20%) may need more intensive or prolonged therapy.
• Your doctor uses both staging and risk to create your personalized treatment plan.

Multiple myeloma is a cancer of the bone marrow and blood cells that circulate throughout the entire body. Because it is a blood-based disease, the traditional tumor staging systems used for solid tumors — which measure tumor size and metastatic spread — do not apply. Instead, staging systems specific to myeloma have been developed to measure disease burden and guide prognosis.

Today, myeloma is most meaningfully categorized into two broad groups: standard-risk and high-risk multiple myeloma (HRMM). Approximately 80% of patients have standard-risk disease, while roughly 20% have HRMM — a more aggressive form that tends to relapse more quickly after treatment.

Staging vs. Risk Stratification

While often discussed together, staging and risk stratification serve distinct clinical purposes:

• Staging describes the extent or burden of disease. It is most significant at the time of diagnosis and draws on blood and bone marrow laboratory values.
• Risk stratification classifies a patient's likelihood of disease response to treatment and potential for disease progression. It guides decisions about treatment intensity, treatment duration, and clinical trial enrollment.

Multiple myeloma often develops gradually from precursor conditions called monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) (https://www.myeloma.org/what-are-mgus-smm-mm). These are asymptomatic stages where abnormal plasma cells are present but not yet causing organ damage. When biomarkers indicate the disease is progressing toward symptomatic myeloma or already causing problems (defined by CRAB criteria: elevated Calcium, Renal failure, Anemia, or Bone lesions), treatment is initiated.
 

Learn More About Multiple Myeloma

For more information about myeloma disease progression and related topics, visit our online resource library (https://www.myeloma.org/publications-videos) for free, downloadable resources. You can also direct your questions to one of our experts when you phone our InfoLine (https://www.myeloma.org/infoline). Our compassionate coordinators can chat with you at a time that works for you.