Multiple Myeloma: Diagnosis, Staging & Care

This page is for people who have just been told they have multiple myeloma. It explains how doctors decide whether it needs treatment, how it is staged, and what to ask.

Once a bone marrow biopsy confirms multiple myeloma, two questions follow. How much disease is present? How is it likely to behave? Staging helps answer both. It does not describe where the cancer is, the way staging does for a tumor like breast or lung cancer. Instead, it combines blood test results to estimate how much myeloma is in your body and how aggressive it may be.

Doctors first decide whether myeloma is active enough to need treatment now. They look for four types of organ damage. Doctors remember them with the letters CRAB: high Calcium in the blood, Renal (kidney) problems, Anemia (low red blood cells), and Bone damage, such as fractures or lesions on imaging. Finding one or more of these moves someone from "smoldering myeloma" into "active myeloma." Certain high-risk lab markers can do the same, even without symptoms. Smoldering myeloma is usually watched. Active myeloma is treated.

Active myeloma is staged using the R-ISS, which relies on three blood results plus chromosome testing:

• Stage I: Beta-2-microglobulin under 3.5 mg/L, albumin at or above 3.5 g/dL, no high-risk chromosome changes, and normal LDH (a blood enzyme).
• Stage II: Results that fall between stage I and stage III.
• Stage III: Beta-2-microglobulin at or above 5.5 mg/L, combined with either a high LDH level or specific high-risk chromosome changes found on FISH testing.

Beta-2-microglobulin is a protein made by myeloma cells. Higher levels usually mean more disease. Albumin is a protein made by the liver; lower levels can reflect how sick the body is from the disease. Stage is a snapshot used for planning and comparing outcomes across large groups of patients. It is not a countdown clock for any one person.

NCI says stage at diagnosis is a strong predictor of survival but has little influence on the choice of treatment, because almost everyone with myeloma has disease spread through the marrow. Stage is also used to compare outcomes in research. People at every stage are treated with the goal of controlling the disease. Your chromosome (cytogenetic) results, kidney function, age, and overall fitness all shape the plan alongside the stage number.

Staging results feed into a first-treatment plan. This commonly combines a targeted drug, an immunotherapy-type drug called a monoclonal antibody, and a steroid. Many people who are fit enough are also considered for a stem cell transplant using their own cells, either soon after diagnosis or later. Ask your team to walk through why a specific combination and timing were chosen for your stage and risk category.

• Do I meet CRAB criteria, or am I being watched as smoldering myeloma?
• What is my R-ISS stage, and which lab values determined it?
• Are my chromosome (cytogenetic) results standard-risk or high-risk?
• How does my stage affect the treatment being recommended?
• Is a stem cell transplant part of my plan, and if so, when?

• Call 911 or go to an emergency department if back pain comes with new weakness in your legs, numbness, or trouble controlling your bladder or bowel. Myeloma weakens the spine, and pressure on the spinal cord has to be relieved fast to protect walking. Do not drive yourself.
• Call 911 or go to an emergency department if you become confused or very drowsy, with heavy thirst, vomiting and weak muscles. That mix points to the high calcium in the C of CRAB, which needs treatment in hospital. Do the same if your temperature reaches 100.4°F (38°C) or higher, since low antibody levels make infection dangerous here and CDC treats fever during cancer treatment as an emergency. Do not drive yourself.
• Call your care team right away if you are passing much less urine than usual, or your ankles and face are puffy. Myeloma can damage the kidneys, the R in CRAB.
• Call your care team right away if a bone starts hurting sharply after a small knock, or tiredness and breathlessness are creeping up on you. These match the B and A of CRAB. For chest pain or trouble breathing, call 911 or go to the ER.

• American Cancer Society — Bone Metastases
• National Cancer Institute — Infection and Neutropenia during Cancer Treatment
• National Cancer Institute — Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment (PDQ)
• CDC — Watch Out for Fever (Preventing Infections in People With Cancer)