Multiple Myeloma
What is multiple myeloma? Everything about the causes, symptoms, and the most effective treatments for this plasma cell cancer.
Symptoms and Causes
Myeloma, commonly known as multiple myeloma, is a type of cancer that affects the plasma cells in the bone marrow, which are a type of white blood cell responsible for producing antibodies (also known as immunoglobulins). As a result, monoclonal antibodies or paraproteins are produced, preventing the immune system from functioning properly.
There are several types of myelomas depending on the affected immunoglobulins:
- IgG Multiple Myeloma: Produces an excess of type G immunoglobulin (which belongs to the heavy polypeptide chains that form antibodies). It is the most common type.
- IgA Multiple Myeloma: The second most common type. It affects type A immunoglobulin and can cause tumors on the outer part of the bone.
- IgD Multiple Myeloma: A rare type that generates large amounts of type D immunoglobulin and usually does not appear alone but in conjunction with leukemia.
- IgE Multiple Myeloma: Similar to IgG myeloma but affects type E immunoglobulin. Like IgD myeloma, it is often associated with plasma cell leukemia.
- Macrofocal Myeloma: Destroys parts of the bones (lytic lesions) and reduces the plasma cells in the bone marrow. However, the tumor burden is low, so it generally has a good prognosis.
- Non-Secretory Multiple Myeloma: A very rare and difficult-to-diagnose form. The abnormal plasma cells (myeloma cells) do not produce immunoglobulin or do so in very small amounts.
- Light Chain or Bence Jones (BJ) Multiple Myeloma: A highly aggressive variant affecting kappa and lambda light chains, which form antibodies when they bind to proteins. It primarily affects the nervous system and kidneys.
This disease primarily affects people over 65 years old and is very rare in individuals under 50. Thanks to scientific advancements, new treatment therapies have significantly improved survival rates, which are now double what they were a few years ago.
Symptoms
The early stages of multiple myeloma, as well as some of its subtypes, do not present symptoms, making diagnosis challenging. When symptoms do appear, the most common ones include:
- Kidney problems
- Anemia
- Bone pain, especially in the back
- Fatigue
- Increased risk of bone fractures
- Frequent infections
- Easy bruising or bleeding
- Weight loss
- Hypercalcemia (elevated calcium levels in the blood)
Causes
The exact causes of multiple myeloma are still unknown. However, abnormalities have been detected in certain oncogenes (genes responsible for promoting cell growth).
Risk Factors
The factors that increase the likelihood of developing myeloma include:
- Age: It is more common in people over 65.
- Family history.
- Plasma cell disorders such as monoclonal gammopathy of undetermined significance (MGUS) or solitary plasmacytoma.
- Obesity.
Complications
Multiple myeloma can cause:
- Increased susceptibility to infections, as the body cannot fight them effectively.
- Bone problems.
- Kidney disease.
- Anemia (low red blood cell levels).
Prevention
Multiple myeloma cannot be prevented since most risk factors are uncontrollable.
What kind of doctor treats myeloma?
Myeloma is diagnosed and treated by hematologists, medical oncologists, radiation oncologists, or nuclear medicine specialists.
Diagnosis
Because it is often asymptomatic, early diagnosis of multiple myeloma is difficult. Some of the tests used to detect it include:
- Blood tests: Provide a count of red blood cells, white blood cells, platelets, and immunoglobulins. Additionally, creatinine, albumin, and calcium levels are checked, as abnormal values may indicate plasma cell cancer.
- Urine tests: Detect the presence of myeloma protein.
- Imaging tests: X-rays, magnetic resonance imaging (MRI), computed tomography (CT scan), or positron emission tomography (PET scan) are typically performed to identify tumors, their size, and their location.
- Genetic studies: Identify mutations in patients for whom other tests are inconclusive. One of the most commonly used techniques is fluorescence in situ hybridization (FISH), which involves applying a dye that binds to a part of the chromosomes, making most alterations visible.
- Bone marrow biopsy: A sample is analyzed to examine how the cells are grouped, as well as their shape, size, and appearance. Additional analyses include:
- Flow cytometry: Detects the presence of abnormal cells.
- Cytogenetics or karyotyping: Examines the chromosomes in bone marrow cells, as myeloma cells may present excess, deficiency, translocations, or deletions.
Treatment
Approaches to treating multiple myeloma vary depending on the patient's physical condition and the characteristics of the disease. In some cases, the best approach is to monitor and observe how the condition evolves. In other cases, different combined therapies are necessary to achieve the desired outcome. The most effective treatments include:
- Medications to relieve pain and slow the growth of malignant cells.
- Targeted therapy: Uses drugs that specifically attack substances that promote the multiplication of cancer cells.
- Immunotherapy: Uses drugs that strengthen the immune system so it can fight cancer.
- CAR-T cell therapy: A type of immunotherapy in which immune cells are modified in the laboratory by adding a chimeric antigen receptor (CAR) gene and then reintroduced into the bloodstream to destroy tumor cells.
- Bone marrow transplant: Recommended for patients under 70 after receiving some of the previously mentioned treatments. In this procedure, blood-forming cells are extracted, treated with chemotherapy, and then reinjected to allow the bone marrow to recover from the disease.
- Chemotherapy: Uses chemical drugs to destroy cancer.
- Radiotherapy: Uses high-energy rays (usually X-rays) to shrink or completely destroy cancer cells.
