Hematologic malignancy is often presented as cancer of the blood. This is cancer that develops from blood cells. Leukemias, myelomas, and lymphomas are types of hematologic malignancies. Their characteristics and symptoms differ. Treatment for blood cancer can also be different depending on the case.

Definition of hematologic malignancies

By definition, a hemopathy is a disease of the blood. We speak of malignant hemopathy to designate a blood cancer. This is a malignant tumor that develops from hematopoietic cells or blood cells.

Types of hematologic malignancies

Malignant hemopathies do not all have the same course. They can be classified into two categories:

• chronic malignant hemopathies, evolving over one or more years;
• acute malignant hemopathies, progressing over a few days or weeks.

It is common to distinguish three main types of hematologic malignancies:

• leukaemias which develop from young blood cells in the bone marrow and spread through the bloodstream;
• myelomas which are characterized by an overgrowth of plasma cells (a type of white blood cell) within the bone marrow;
• lymphomas which develop from lymphocytes (family of white blood cells), most often in the lymph nodes (organs ensuring filtration of the lymphatic system).

Each type of blood cancer can then be divided into subtypes. We distinguish in particular:

• acute or chronic lymphoid leukemia;
• acute or chronic myeloid leukemia;
• multiple myeloma;
• diffuse large B-cell lymphoma;
• Hodgkin lymphoma;
• non-Hodgkin lymphoma;
• etc.

Sometimes it is considered that the name “blood cancer” can only be associated with leukemia. Myelomas are then considered “cancers of the bone marrow” and lymphomas as “cancers of the ganglia”.

Causes of hematologic malignancies

The causes of blood cancers are still poorly understood. Scientists agree that these malignant hemopathies are the consequence of a combination of genetic and environmental factors.

Risk factors

Various risk factors have thus been identified:

• family history of blood cancers;
• certain viral infections;
• blood problems, especially myelodysplastic syndromes (diseases affecting the bone marrow);
• ionizing radiation;
• toxic products ;
• tobacco ;
• etc.

Diagnosis of hematologic malignancies

It is based on a clinical examination which can then be completed by:

• a blood test to check for abnormalities related to blood cancer;
• examining the urine, which can also identify certain abnormalities;
• medical imaging tests such as an x-ray, CT scan, magnetic resonance imaging (MRI) or positron emission tomography;
• a bone marrow biopsy, a test that takes a sample of bone marrow.

Hematologic malignancies represent on average 10% of new cancer cases. They can appear at any age in both men and women. Nevertheless, it seems that they are more common in men over 60 years old.

Symptoms can vary greatly depending on the type of hematologic malignancies. However, it is possible to distinguish typical signs and more specific signs.

Typical damage to the organism

Hematologic malignancy affects the general functioning of the body. Several signs of dysfunction can be observed:

• tiredness ;
• a general feeling of discomfort or illness;
• loss of appetite;
• weight loss;
• weakness and dizziness;
• night sweats;
• etc.

Specific disorders

Depending on the type of hematologic malignancy, specific disorders can occur:

• bone pain;
• blood abnormalities such as anemia;
• kidney dysfunction;
• etc.

Several treatments can be considered depending on the type of hematologic malignancy and the patient’s condition. For example, the management of hematologic malignancies may be based on:

• chemotherapy, a chemical treatment that aims to destroy cancer cells;
• radiation therapy, which uses high-energy rays or particles to destroy cancer cells;
• targeted therapy, which attacks specific vulnerabilities in cancer cells;
• stem cell transplantation, which consists of an injection of blood stem cells that may come from a donor or from the patient himself (autologous transplant).

A lot of research is being done on the subject. To date, prevention is essentially based on maintaining a healthy lifestyle and combating avoidable risk factors (tobacco, toxic substances, etc.).