Introduction: Who Should Undergo Diagnostics
People who have already been diagnosed with multiple myeloma and are receiving treatment should undergo regular diagnostic testing to monitor how well their therapy is working. This ongoing monitoring is crucial because it helps detect if the cancer has become resistant to treatment, a condition known as refractory multiple myeloma.[1]
Diagnostic testing becomes especially important if you notice that symptoms are not improving or are getting worse while you are on treatment. If bone pain persists or worsens, if you develop new symptoms like weakness, frequent infections, or shortness of breath that don’t go away, these could be warning signs that your current treatment is no longer effective. In such cases, your doctor will order specific tests to determine whether the myeloma has become refractory.[4]
Patients who fail to achieve at least a minimal response after receiving their initial therapy should also undergo diagnostic evaluation. When the disease progresses while you are actively receiving treatment, or if it progresses within 60 days of completing your most recent treatment, doctors need to perform diagnostic tests to confirm that the myeloma has become refractory. This early detection allows for prompt adjustment of treatment strategies to help control the disease and reduce complications.[1]
Diagnostic Methods for Identifying Refractory Multiple Myeloma
Several types of diagnostic tests are used to determine whether multiple myeloma has become refractory. These tests examine the blood, bone marrow, and urine to assess how the disease is responding to treatment and whether cancer cells are still growing despite therapy.[2]
Blood Tests
Blood tests are among the most important tools for monitoring refractory myeloma. A complete blood count, often abbreviated as CBC, measures the levels of red blood cells, white blood cells, and platelets in your blood. Multiple myeloma can lower the numbers of these cells, and if these levels don’t improve or continue to drop during treatment, it may indicate that the treatment isn’t working.[8]
Blood chemistry tests check for various proteins and other substances in your blood. These tests can reveal high calcium levels and low levels of a protein called albumin, both of which can be affected by multiple myeloma. Blood tests also detect abnormal antibody levels that myeloma can affect. One particularly important blood test looks for something called M protein, which is an abnormal protein made by myeloma cells. If M protein levels remain high or increase during treatment, this suggests the myeloma is not responding to therapy.[4]
Blood and urine immunoglobulin studies are specialized tests that examine antibody proteins. These proteins can build up in the bone marrow and blood when myeloma is active, and monitoring their levels helps doctors understand whether treatment is controlling the cancer or if it has become refractory.[4]
Urine Tests
Urine tests check for proteins and a waste product called creatinine. High levels of certain proteins in the urine can indicate that multiple myeloma has damaged your kidneys. Doctors often request a 24-hour urine test, which means you collect all of your urine over a full day so that laboratories can measure the total amount of abnormal proteins being released. If these levels remain high during treatment, it suggests the myeloma is still active and potentially refractory.[4]
Bone Marrow Tests
Bone marrow testing is a critical diagnostic procedure for refractory myeloma. During a bone marrow aspiration and biopsy, your doctor removes a sample of liquid or tissue from your bone marrow. A laboratory then examines this sample to count how many abnormal plasma cells are present and to look for specific genetic changes in the cancer cells.[8]
Three specialized tests are often performed on bone marrow samples to provide detailed information about the myeloma. Cytogenetic analysis involves counting the chromosomes in cancer cells and checking for any alterations or damage. This test helps doctors diagnose cancer, determine the best treatment options, and monitor how well treatment is working. The FISH test, which stands for fluorescence in situ hybridization, is a laboratory test that identifies and counts specific genes or chromosomes in cancer cells. Scientists create artificial DNA containing fluorescent dye and add it to your tumor samples. The DNA binds to specific genes and chromosomes and lights up when viewed under a microscope, helping doctors determine appropriate treatment and confirm the subtype of multiple myeloma. Flow cytometry is another laboratory test that measures the number of cells, the percentage of live cells present, and characteristics such as size, shape, and special markers on the cell surface. Your cells are stained with a fluorescent dye, placed in a fluid, and passed through a beam of light one at a time. How the cells react to the light provides insight for diagnosis and treatment of multiple myeloma.[4]
Imaging Tests
Imaging tests allow your doctor to see inside your body and check whether cancer has damaged your bones or if tumors have grown. These tests are important for determining if myeloma has become refractory because they can show whether bone damage is worsening despite treatment.[8]
An X-ray uses radiation in low doses to make pictures of your bones. It can show areas of bone loss from multiple myeloma. A skeletal bone survey involves taking X-rays of multiple bones throughout your body to check for damage caused by myeloma cells.[4]
Magnetic resonance imaging, or MRI, uses powerful magnets and radio waves to create three-dimensional pictures of your bones and soft tissues. It can reveal areas where cancer has damaged bones and is particularly good at showing soft tissue details that X-rays might miss.[4]
A CT scan, or computed tomography scan, is a powerful type of X-ray that makes three-dimensional images of your bones to find areas of cancer. It provides more detailed images than regular X-rays and can help identify bone damage that might not be visible on standard X-rays.[8]
A PET scan, which stands for positron emission tomography, uses a radioactive sugar that cancer cells consume. A special camera then takes pictures to show areas of active cancer in your body. This test is particularly useful because it can distinguish between active cancer and scar tissue or areas of healing.[4]
Physical Examination
A thorough physical examination by your doctor is also an important part of diagnosing refractory myeloma. Your doctor will check for signs of disease progression, such as bone tenderness, swelling, or other physical changes that might indicate the cancer is not responding to treatment.[4]
Diagnostics for Clinical Trial Qualification
When patients with refractory multiple myeloma are being considered for enrollment in clinical trials testing new treatments, they must undergo specific diagnostic tests to determine if they meet the study’s entry requirements. These tests serve as standard criteria for enrolling patients and help ensure that the trial includes appropriate candidates who can safely participate and from whom researchers can gather meaningful data.[1]
Blood tests are routinely required for clinical trial eligibility. These typically include a complete blood count to assess the levels of different blood cells, blood chemistry studies to check kidney and liver function, and tests to measure the levels of M protein and other abnormal proteins produced by myeloma cells. Clinical trials often have specific thresholds for these values, and patients must meet certain criteria to qualify for participation.[4]
Bone marrow biopsies are frequently required as part of clinical trial screening. Researchers need to confirm the presence of myeloma cells in the bone marrow and may also need to perform genetic testing on these cells to identify specific chromosomal abnormalities or gene mutations. Some clinical trials specifically target patients whose myeloma cells have particular genetic characteristics, so these specialized tests help match patients to appropriate studies.[4]
Imaging studies such as skeletal surveys, MRI scans, or PET-CT scans may be required to document the extent of bone disease and to identify any masses or tumors outside the bone marrow. These baseline images allow researchers to measure how well the experimental treatment is working by comparing them to images taken during and after treatment.[4]
Urine tests, including 24-hour urine collections, are often necessary to measure the amount of abnormal proteins being excreted and to assess kidney function. Many clinical trials have specific requirements regarding kidney function, as some experimental treatments may not be safe for patients whose kidneys are already significantly damaged.[4]
Clinical trials may also require specialized testing that goes beyond standard diagnostic procedures. For instance, some studies use minimal residual disease testing, which employs extremely sensitive techniques to look at blood or bone marrow samples and detect even tiny numbers of remaining cancer cells that standard tests might miss. This type of testing helps researchers understand how effectively a new treatment is eliminating myeloma cells.[11]





