Prognostic factors
Prognostic factors are essential factors that make it possible, to a certain extent, to predict the evolution of the disease and the effectiveness of the treatment. They reveal the aggressiveness of the disease, its extent and the capacity of the patient to bear the disease or the side effects of the treatments. They are studied in the initial evaluation of the disease, the most telling one serve to adapt the treatment.
Age
Age is of course an essential factor. Although lymphomas in older patients do not seem to differ very much from those in younger patients, the capacity to bear intensive treatments decreases with age. The treatments are therefore adapted to the age, and it is now not uncommon for chemotherapy to be proposed to patients of more than 80 years old.
Extent (lymphoma stages)
The extent of the disease is defined by its stage. This stage is determined by the results of the initial evaluation: clinical investigation, CAT scan, medullary biopsy, lumbar puncture and sometimes other investigations.
Four lymphoma stages have been defined:
- Stage I: affectation of a single node or a single organ, for example a lymphoma of a neck lymph node or an isolated stomach lymphoma.
- Stage II: affectation of several nodes or several organs, but the disease remains limited to the lower part or the upper part of the body. For example, affectation of the neck, armpit and mediastinal nodes, (thorax nodes), or affectation of the stomach and abdominal nodes.
- Stage II: affectation of several nodes in the lower and upper parts of the body. For example, affectation of the neck and abdominal nodes.
- Stage IV: disseminated affectation of various organs. For example, affectation of the bone marrow or the neck and intestinal nodes.
Other elements indicating the extent of the disease are sometimes important: particular affectation site (cerebral lymphoma for example), number of affected nodes or organs, size of the tumour or tumours.
General state of health of the patient
The patient’s general state of health at the time of the diagnosis is also an important factor, as it reveals their capacity to bear the illness. In order to quantify their general state of health, “scales of performance” have been created. The most frequently used scale is the ECOG, ranging from 0 to 4:
- 0: No affectation of the general state of health, the patient lives a normal life.
- 1: Tiredness is present, but the patient can perform most everyday actions.
- 2: Fatigue that forces the patient to rest during the day.
- 3: The patient remains bedridden for more than half the day.
- 4: The patient no longer leaves the bed.
Prognostic indexes
Prognostic indexes are combinations of prognostic factors that make it possible to establish a score, with the aim of predicting the evolution of the lymphoma and thus determining the best treatment to provide.
The International Prognostic Index for large-cell lymphomas: IPI
The IPI was established on the basis of an international study conducted by the leading lymphoma study groups on data from more than 4000 patients. This index is very widely used. The elements retained as being the most important are:
- Age (below 60 / over 60 years old)
- LDH concentration (normal / high)
- General state of health (ECOG 0-1 / 2-4)
- Stage (I-II / III-IV)
- The number of affected organs (0 or 1 / more than 1)
To calculate the IPI, the number of unfavourable factors are added together, it therefore varies from 0 to 5.
The International Prognostic Index for follicular lymphomas: FLIPI
For the FLIPI, the elements retained as being the most important are:
- Age (below 60 / over 60 years old)
- LDH concentration (normal / high)
- Haemoglobin concentration (> 12)
- Stage (I-II / III-IV)
- The number of affected nodes (4 or less / more than 4)
New prognostic factors
Many studies have been and are being conducted to search for biological factors that make it possible to predict the severity of the lymphoma.
Factors being studied:
- Genetic anomalies of lymphoma cells
- Disruption of certain genes
- Factors present in the blood
Currently, none of these factors has been universally recognised. We hope that these factors will make it possible to discover new, more effective and more specific treatments.