Multiple Myeloma (MM) is a tumor characterized by an abundance of abnormal plasma cells within the bone marrow, which lodge inside the bones of the skull, spine, rib cage, pelvis, the areas near the shoulders and hips.
Plasma cells are a type of white blood cell less than 5% in size that produce immunoglobulins, proteins that protect us from germs in an infection. All people have this type of cell, which during their maturation produce only one type of immunoglobulin and no longer reproduce.
The plasma cells of patients with myeloma change and become abnormal and expand abundantly, occupying a large part of the bone marrow.
Are there many cases of myeloma and can it be hereditary?
In order of frequency, MM is the second most common hematological disease, after non-Hodgkin’s lymphoma. Every day there are four or five new cases in a radius of 100,000 inhabitants. Therefore, in Spain around 2,000 new cases will be diagnosed each year.
The hematologist María Casanova indicates that the typical profile of a patient affected by multiple myeloma “is a person over 70 years of age who usually goes to the doctor because of the appearance of bone pain, secondary to the skeletal involvement characteristic of this disease, or because of increased tiredness as a result of the anemia associated with myeloma. Only 5-10% of patients are under 40 years of age”.
There is a possibility that multiple myeloma can be passed from parents to children, since 6% of the diagnoses of this tumor occur in people with close relatives who have previously suffered some alteration of the plasma cells.
Symptomatology
As we have already mentioned, plasma cells produce immunoglobins, which are proteins that defend us from external attacks. Myeloma cells do not produce these types of immunoglobins, thus altering the immune system and increasing the chances of developing infections.
Clinically active MM alters the correct functioning of the bone marrow and causes anemia and an increased risk of infections, as it directly affects the functioning of the immune system.
It also causes decalcification of the bone, causing intense bone pain in the affected person and can lead to spontaneous fractures. It is also associated with hypercalcemia, an increase of calcium in the blood, which could cause some serious alterations.
Bone pain, the main symptom of the disease
Like conventional plasma cells, MM cells produce a type of immunoglobin called a monoclonal band, which if lodged in the kidney could lead to renal failure.
When MM causes anemia, bone lesions, hypercalcemia or renal failure, it is necessary to start treatment as soon as possible, since it affects the so-called target organs. In contrast, asymptomatic multiple myeloma does not require immediate treatment, as it can remain without visible symptoms throughout life.
However, there are certain ways of predicting future symptoms such as: blood tests, and bone marrow or imaging studies. These are therefore considered criteria to be taken into account when deciding whether to start treatment early.
What is the prognosis of multiple myeloma?
We must assume that MM is still an incurable disease today. In addition, many patients may suffer relapses after the first treatment and it will be necessary to undergo treatment several times.
Despite this, the prognosis is not poor, but is highly variable. About 10% of patients will respond excellently to treatment and are unlikely to relapse. These patients are referred to as “functionally cured”, because although it does not manifest itself for many years, it is impossible to know if it will manifest itself again.
On the other hand, 10-15% of patients may respond well to initial treatment, but relapse early. In these cases the patient is predicted to have about two years to live. Most patients will therefore usually respond correctly to the first treatment. Later, it will be seen whether the symptoms disappear or, on the contrary, worsen, but without showing a vital risk in the short term. On the other hand, in the long term, the future is more uncertain because it will depend on the frequency and severity of the relapses suffered.
How to treat a case of myeloma?
Currently, there are several useful drugs to treat MM, although it is essential to personalize the treatment according to the characteristics of the affected person, his age and the severity of his symptoms.
The standardized treatments are:
- Targeted therapy: used when there are specific abnormalities within cancer cells that allow survival. These drugs prevent the disintegration of proteins, produced by a substance in the myeloma cells. This therapy causes the death of the myeloma cells. On the other hand, there are other targeted therapy methods involving monoclonal antibody drugs that attach to proteins present on the cancer cells and eliminate them.
- Immunotherapy or biological therapy: the body’s own immune system is used to fight myeloma cells. This treatment helps to better identify and attack the cancer cells.
- Chemotherapy: Chemotherapy drugs kill fast-growing cells, including myeloma cells. They are used in high doses before a bone marrow transplant.
- Corticosteroids: these are responsible for regulating the immune system to control inflammation in the body and act against cancer cells.
- Bone marrow transplantation: a distinction is made between two types:
- Autologous transplant: it is necessary to use stem cells from the patient himself, previously extracted and frozen, after having carried out several treatment inductions and after verifying that the patient is in good condition in relation to his blood disease. The patient then receives intensive chemotherapy sessions, which are administered to kill residual tumor cells. Unfortunately, this treatment also eliminates healthy bone marrow cells, so previously collected stem cells are administered to avoid problems due to the decrease in bone marrow cells. This is the most common transplant to treat cases of MM.
- Allogeneic transplant: in this case the stem cells come from a donor, who may or may not be a family member, with tissue similar to that of the affected person. In this process, the infected bone marrow is replaced by healthy bone marrow.
- Radiotherapy: the use of protons and X-rays, with the intention of eliminating tumor cells and thus stopping their growth. It can be used to shrink malignant cells in a specific area, such as when plasma cells form a plasmacytoma-type tumor, which destroys bone and causes pain.