CHEMOTHERAPEUTIC TREATMENT FOR MULTIPLE MYELOMA
- INTRODUCTION
GENERAL
Chemotherapy is a drug-based treatment. It is a systemic treatment because it affects the whole body as the drugs travel through the blood to reach cancer cells throughout the body. They can be administered intravenously or orally.
These drugs are intended to destroy tumor cells. The peculiarity of these drugs is that they are toxic to all cells capable of dividing. As a result, chemotherapies block the proliferation of cancerous cells just like normal cells, by preventing the synthesis of DNA essential for cell duplication and by destroying the fibers of the cell frame (which structure the cell).
IN PRACTICE…
Chemotherapy is given in cycles. Each 1 period is followed by a period of therapeutic rest allowing the recovery of the normal cell lines affected by the drug(s).
The total duration of chemotherapy varies, depending on the therapeutic regimens used.
The treatment protocol is defined in advance by the doctor in charge but it can be modified according to the response of the disease.
This treatment is most often administered in a day hospital. However, sometimes hospitalizations are necessary due to the type of treatment or the condition of the patient.
- MEDICATIONS USED IN CHEMOTHERAPY TREATMENT FOR MULTIPLE MYELOMA
CORTICOIDS
It is an option that can be proposed, at the very beginning of the disease or as a maintenance treatment.
In this case, the corticosteroid is administered according to a so-called pulsed protocol, that is to say in short periods, at high doses, followed by a cessation of treatment, to reduce the side effects.
We can, for example, give you 40 mg of dexamethasone orally in a pulsed fashion, that is to say from D1 to D4, then from D9 to D12, then from D17 to D20.
MELPHALAN (ALKERAN™) ALONE
A little throwback
Melphalan was synthesized by F. Bergel and JA Stock in 1953 from a nitrogen mustard, a component of combat gases used during the First World War, by substituting a methyl group for the amino acid, phenylalanine.
The intention of the researchers was to "starve" tumors that consume large amounts of phenylalanine or tyrosine, such as malignant melanoma, by administering a "decoy" to them.
Melphalan
The levorotatory isomer, considered the most active, was developed and named melphalan (Alkéran TM ). This alkylating agent, initially used to treat solid tumors, was quickly tested in hematology.
BENDAMUSTIN (LEVACT/TREANDA™)
This molecule, synthesized for the first time in the early 1960s in East Germany (ex-GDR), has an original chemical structure combining properties of both alkylating agents and purine analogues.
Its indications
It is indicated for the first line treatment of multiple myeloma in combination with prednisone in patients over the age of 65 who are not eligible for autologous stem cell transplantation and who have neuropathy at the time of diagnosis excluding the use treatment comprising thalidomide or bortezomib (120-150 mg/m² on D1 and D2, prednisone 60 mg/m² IV or per os from D1 to D4; every 4 weeks).
His tolerance
It is satisfactory with essentially some nausea and vomiting easily prevented by the use of the usual drugs, and haematological toxicity such as dose-dependent and reversible neutropenia and thrombocytopenia.
IN PRACTICE, THE DURATION OF TREATMENT
A year
12 treatments or less until a stable plateau phase is obtained
Stop at the plateau
Resumption in case of relapse more than 6 months after stopping
TRADITIONAL PROTOCOLS
THE PM PROTOCOL
The Alexanian Protocol
It was the standard initial treatment for multiple myeloma. This protocol is sometimes called the Alexanian protocol, named after the doctor who developed it. The goal of the MP protocol is to induce a moderate decrease in blood cells and platelets (cytopenia).
The administration is done in discontinuous cures (resumed at D 42). The MP protocol, orally, includes the following medications which must be taken on an empty stomach, 4 days in a row (from D1 to D4): melphalan (Alkéran™) 9 mg/m² combined with prednisone, a corticosteroid (derivative cortisone), at a dose of 100 mg. The chemotherapy cycle is repeated every 6 weeks.
The effects of the treatment will be monitored by blood tests (NFS) carried out a fortnight after the start of the first courses. The results of the analyzes will make it possible, if necessary, to modulate the doses of the following cures. Each cure is to be postponed if the prior NFS indicates an insufficient number of leukocytes (< 3000/mm 3 ) and platelets (< 100,000/mm 3 ).
Therapeutic intensification
Melphalan is then used at a high dose with an autograft of peripheral stem cells and the administration of hematopoietic growth factors.
OTHER PROTOCOLS
They have the particularity of always including Melphalan and Prednisone (MP).
MCP: Melphalan 9 mg/m² oral from D 1 to D 4 + Cyclophosphamide (Endoxan™) which is given intravenously on D 1 + Prednisone 100 mg in the form of tablets from D 1 to D 4
V-MCP: Vincristine (Oncovin™) which is added to MCP
VB-MCP (M2): Bicnu™ (carmustine) at a dose of 20 mg/m² IV on D1 which is added to V-MCP.
The chemotherapy cycle is repeated every 5 weeks.
These protocols are usually offered when the myeloma is aggressive and there is renal failure. It is often considered a first step before bone marrow transplantation.
The VAD protocol
It includes continuous infusions of Adriblastine™ and vincristine combined with high-dose corticosteroid therapy of dexamethasone.
Vincristine (Oncovin™): 0.4 mg IV from D1 to D4
Adriamycin (doxorubicin): 9 mg/m² IV continuously from D1 to D4
Dexamethasone (Soludecadron™): 40 mg IV from D1 to D4.
The chemotherapy cycle is restarted every 3 weeks for 3 to 6 cures.
The VAMP protocol
It uses methylprednisolone instead of dexamethasone.
Vincristine (Oncovin™): 0.4 mg IV from D1 to D4
Adriamycin (doxorubicin): 9 mg/m² IV continuously from D1 to D4
MP for methylprednisolone.
The chemotherapy cycle is restarted every 3 weeks for 3 to 6 cures.
This treatment has constraints because it requires iterative hospitalizations and the installation of a central venous line.
This chemotherapy requires hematological monitoring every 8 days. The risk is a decrease in white blood cells (neutropenia) especially between D7 to D14 with a high risk of complications, especially infectious.
The VBAP protocol
It is more recent and its main advantage lies in the fact that it presents fewer constraints because the chemotherapy session only lasts a few hours. Alternate protocols use VMCP and VBAP in turn.
Vincristine (Oncovin™): 1 mg/m² IV on D1
Bicnu™ (carmustine): 20 mg IV on D1
Adriblastine™ (doxorubicin): 30 mg/m² IV on D1
Prednisone: 60 mg orally from D1 to D4
The chemotherapy cycle includes 3 to 6 cures, every 3 weeks
BEFORE STARTING CHEMOTHERAPY...
PRECAUTIONS TO TAKE
Go to the dentist....
At the time of diagnosis and before starting treatment.
It is preferable to eliminate any source of infection before starting chemotherapy. The most common source of infection is dental. If your chemotherapy treatment is only scheduled in 2 or 3 weeks, you have time to have your teeth examined and treated by your dentist before starting.
A blood test will be systematically carried out before chemotherapy
It is done to ensure the proper functioning of organs essential for the metabolism and elimination of drugs, such as the liver and the kidney. In this blood test, it will also be checked that the circulating blood cells (white blood cells, red blood cells and platelets) are at a satisfactory level, because these are the healthy cells of the body whose production is most sensitive to drugs. chemotherapy. If the level of red blood cells (or more precisely, the level of hemoglobin) is too low, you will be offered to receive a blood transfusion (red cells) before carrying out chemotherapy.
Some chemotherapy drugs may exhibit organ-specific toxicity.
Tests can then be useful to check that this organ is working satisfactorily in you before administering the medicine. Thus, an ultrasound or a cardiac scintigraphy is often proposed before administering certain drugs such as anthracyclines which can be toxic to the heart at higher doses than the usual doses.
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