Adult haematology
OVERVIEW
Blood or “haematological” cancers are divided into five major groups: leukaemia, lymphoma, myeloproliferative syndrome, multiple myeloma and myelodysplasia.
Leukaemia is characterised by excessive white cell numbers in blood and bone marrow, the production centre for blood cells whose normal development is hindered. Lymphoma is cancer of the lymphatic system, which helps defend the body, especially against infections, and includes ganglia and various other organs, such as the spleen, and bone marrow.
Myeloproliferative syndrome is caused by excessive production of blood cells (red and white cells and platelets) within bone marrow. Myeloma is proliferation of plasmocytes, one specific type of white cell. Finally, myelodysplasia is a pre-leukaemia condition.
A definite diagnosis of blood cancer is obtained through laboratory examinations. In our centre, specialists who carry out these sometimes complicated diagnostic procedures, and doctors specialising in their treatment, pool their knowledge at multidisciplinary meetings. Each case is thus analysed in depth, helping to determine the most suitable approach.
EPIDEMIOLOGY
About 1,200 cases of lymphoma occur each year in Belgium; there are about 300 cases of acute leukaemia and 400 cases of myeloma. Our haematology department is a specialist centre in Belgium.
RISK FACTORS
Blood cancers are commoner in patients with reduced immunity. They are also triggered by excessive exposure to certain products, or handling of these products in the absence of basic precautions. These products include pesticides, insecticides, certain types of radiation, benzene, various solvents, and petrol. Smoking can harm the blood as well as other organs. There is very little, if any, evidence of a familial or genetic pattern.
SYMPTOMS AND DIAGNOSIS
Excessive bleeding, persistent infections, paleness, an enlarged ganglion, bone pains, and a fracture following a minor injury, can all be alarm signals. These signs are however hardly specific, also being found in many non-cancerous diseases.
Diagnosis therefore requires additional examinations. Blood tests determine concentrations of red cells, white cells and platelets, and reveal the presence of abnormal cells in blood. If necessary, bone marrow or ganglia will also be examined under a microscope. These examinations will require a biopsy and can lead to a diagnosis.
Research is now being conducted with the aim of better understanding the finely balanced mechanisms that determine behaviour of malignant blood cancer cells, with the constant aim of improving standards of treatment.
Finally, a PET scan can also be useful in confirming a diagnosis. This modern imaging technique can use a marker to determine the location and activity levels of abnormal ganglia.
The decision on the best treatment to provide depends on regular exchange between specialists who carry out laboratory examinations and those who specialise in the treatments.
Des cellules souches hématopoïétiques peuvent être prélevées, soit dans la moelle osseuse, soit dans le sang périphérique. Ces cellules peuvent alors être réinfusées par voie veineuse, après traitement qui élimine, chez le patient, la moelle osseuse normale mais également la maladie résiduelle. Ceci permettra une reprise de la formation des globules rouges, de globules blancs et de plaquettes.
TREATMENT
Chemotherapy plays an important role in the treatment of leukaemia and lymphoma. Treatment is given partly in hospital and partly in the outpatients’ department.
The Cancer Centre specialists dedicated to treatment of blood cancer were the first in Belgium to suggest this arrangement, which spares patients an excessively long stay in hospital. Fifty to sixty patients are now treated daily in the “day hospital”.
A bone marrow transplant or stem blood-cell transplant is carried out when conventional treatment does not control the disease sufficiently. An “allogeneic” transplant involves taking healthy bone marrow or stem blood cells from a compatible donor (often a family member) and implanting them in the patient. In an autologous transplant, the patient’s marrow is taken and transfused back following intensive treatment.
The multidisciplinary team dedicated to blood cancers was one of the first to use and successfully complete bone marrow transplants. It remains at the forefront in its field.
Targeted therapies, such as antibody transfusions and new drugs used in the treatment of certain blood cancers, are specific. In other words, they act on cancer cells and preserve the rest of the body. These recent medical treatments are an important step forward, improving both efficacy and tolerance, and have been the subject of international studies in which reference centres such as ours have played an active part.
Examen de la moelle osseuse. Image de leucémie myéloblastique aiguë.
All these advances mean that blood cancer prognosis has improved markedly in recent decades. Current treatment now allows many cancers, long since seen as lethal, to be cured.
Some cancers, however, react much less readily to this treatment. Research conducted at our Centre aims to expose the mechanisms behind this resistance to treatment so that an optimum approach can be offered even in the most difficult cases. These complex studies require laboratory researchers and clinicians to work closely together.
Collaboration between laboratory researchers and clinicians involved in large international studies allows patients to benefit from the most up-to-date and effective treatments.
