Chemotherapy is the most widely used and proven cancer treatment. It is cytotoxic, meaning it stops cells from multiplying.
Chemotherapy is used to target tumor cells, which have uncontrolled growth, but it also affects rapidly dividing healthy cells (e.g, mucous membranes, hair, etc.)
Il existe un grand nombre de molécules de chimiothérapie disponibles en oncologie/hé.
Often referred to as molecules, they are distinguished by the phase of the cell cycle during which they act.
The development of a cancerous tumor begins when a single cell starts to degenerate and proliferate in an uncontrolled and often rapid fashion.
The unhealthy cell divides into two, then those two cells divide into two, etc. etc. at an exponential and infinite rate.
This proliferation is divided into several phases :
Chemotherapy is used at the above phases to control tumor growth. To enhance the treatment’s effectiveness, chemotherapy molecules can be combined. This is called chemotherapy protocol and is labelled using the various products’ initials. The drugs are available in different forms: intravenous (the most common), oral, intramuscular and subcutaneous. Chemotherapy is a series of cycles, consisting of one or more molecules administered at regular intervals. The intervals between treatments are determined by expected side effects (to give the body time to recover) and the molecules’ mechanism of action. In some cases, chemotherapy is given orally in a series of regular doses. The number of cycles is often predetermined but will also depend on how the patient responds to treatment. Your oncologist will typically perform a full medical assessment, including blood and imaging tests, every two or three cycles to evaluate the treatment’s effectiveness.
Adverse effects from chemotherapy vary in frequency
and intensity depending on the molecules used.
The most common are:
Anemia: low hemoglobin levels (e.g. a low red blood cells count)
Leukopenia: a decrease in white blood cells, particularly polynuclear neutrophils (which protect against infections)
Thrombocytopenia: a decrease in platelets, which can cause excessive bleeding
While some side effects are immediate, such as fatigue, nausea, and vomiting, most will occur within 7-10 days of treatment.
In most cases, side effects can be minimized or even prevented with specific treatments called pre-medications. Your oncologist should prescribe preventive measures according to your individual tolerance levels and treatment plan.
Chemotherapy is a systemic (general) treatment that impacts cancer wherever it is present in the body.
It is most often used in metastatic (spreading) cancers,
but can be used effectively as a targeted therapy in at least two instances:
It can be used after a radical localized treatment to remove the tumor (surgery or radiation therapy) to minimize the risk of recurrence. Relapses can occur after localized treatment when microscopic cancer cells (not visible on scans or MRI) pass into the bloodstream. These can, sometimes years later, colonize other organs. When this risk is considered significant, chemotherapy may be recommended 4 to 6 weeks after the operation.