What is Multiple Myeloma?
Multiple myeloma is the second most common hematological neoplasm worldwide. It is a malignant tumor of bone marrow cells caused by the proliferation of neoplastic plasma cells, i.e., cells that mutate and become abnormal.
It is found in the bone marrow, where these irregular cells accumulate and lead to the production of a large amount of abnormal antibodies. Unable to perform their protective functions, these antibodies form a heap of disordered proteins, called monoclonal proteins or M proteins/components.
The expansion of multiple myeloma causes bone destruction, as well as pain and fractures in more advanced cases. Kidney failure and recurrent infections can also occur as a result of the disease.
About 7,000 new cases of multiple myeloma are diagnosed in Brazil each year. The disease most frequently affects men and women over the age of 60.
Symptoms and Signs of Multiple Myeloma
Some patients may not have any symptoms, especially if the plasma cells infiltrate the bone marrow in small numbers and the production of M-component is small. Bone pain and fractures, however, can occur even in asymptomatic patients.
When there is more infiltration and more M-protein production, the patient may experience the following symptoms:
- Extreme fatigue;
- Weight loss for no apparent reason;
- Decreased kidney function;
- Leg swelling;
- Excessive thirst;
- Loss of appetite;
- Severe constipation;
- Constant infections.
Because it is asymptomatic in some cases, multiple myeloma can be discovered by chance, during routine tests. The most common is a blood test, revealing anemia and hyperproteinemia.
Imaging tests such as X-rays, CT scans, and MRI scans can help in the evaluation of multiple myeloma by identifying the lytic lesions that are characteristic of the bone disease
A bone marrow biopsy, in which a fragment of bone from the pelvis is taken for laboratory analysis, and a subsequent myelogram can be performed. The purpose of these tests is to quantify the number of plasma cells present. If they detect more than 10% of clonal plasma cells in the bone marrow, multiple myeloma is confirmed.
Other complementary diagnostic procedures are protein electrophoresis and protein immunofixation, both performed by taking blood and urine samples to detect M-protein in blood.
In multiple myeloma treatment, drugs are used in order to destroy, control or inhibit the growth of affected cells.
Some of the possibilities are proteasome inhibitors (which attack diseased cells with less impact on healthy ones), immunomodulators, monoclonal antibodies, and corticoids.
Autologous peripheral stem cell transplantation is generally indicated for patients under 70 years old.
Finally, attention must be paid to supportive treatment, namely physical symptoms that can impair the patient’s quality of life and health. The use of bisphosphonates helps keep bones strong because they inhibit osteoclast-mediated bone reabsorption, reducing bone pain, hypercalcemia, and the incidence of fractures.