Prognosis and survival for chronic lymphocytic leukemia
A prognosis is the doctor's best estimate of how cancer will affect you and how it will respond to treatment. Survival is the percentage of people with a disease who are alive at some point in time after their diagnosis. Prognosis and survival depend on many factors.
The doctor will look at certain aspects of the cancer as well as characteristics of the person (such as their age and if they have other illnesses). These are called prognostic factors. The doctor will also look at predictive factors, which influence how a cancer will respond to a certain treatment and how likely it is that the cancer will come back after treatment.
Prognostic and predictive factors are often discussed together. They both play a part in deciding on a prognosis and a treatment plan just for you. Only a doctor familiar with your medical history, the type and stage and other features of the cancer, the treatments chosen and the response to treatment can put all of this information together with survival statistics to arrive at a prognosis and chances of survival.
The following are prognostic and predictive factors for chronic lymphocytic leukemia (CLL).
Chromosome changes
Chromosomes hold your genetic information. Changes to some chromosomes are used to predict prognosis for CLL, but it is important to understand that the evidence behind these prognosis estimates is from a time when chemotherapy was the only treatment for CLL. As treatment becomes more specialized to target these chromosome changes, the prognosis associated with these changes may also change.
Changes in chromosomes are tested using fluorescent in situ hybridization (FISH). FISH is a laboratory test that looks for losses (deletions) of parts of the chromosomes or gains (additions) in whole chromosomes in the CLL cells.
CLL that has a chromosome 13 deletion with no other chromosome changes means a better prognosis.
A chromosome 11 deletion is associated with the loss of the ATM gene. It predicts a decreased response to chemotherapy, so knowing this helps with planning treatment.
Trisomy 12 (having an extra copy of chromosome 12) is associated with an intermediate prognosis.
CLL with a 17p chromosome deletion (often written as "del(17p)") doesn't respond well to chemotherapy, so it has a poor prognosis.
TP53 gene mutation
The TP53 gene signals the formation of a protein that keeps cells from growing or dividing too fast or in an uncontrolled way. A mutation, or change, of the TP53 gene is also associated with a 17p chromosome deletion. CLL with mutated TP53 doesn't respond well to chemotherapy, so it has a poor prognosis.
IGHV gene mutation
CLL with an unmutated, or unchanged, gene for IGHV (immunoglobulin heavy chain variable region) is often more aggressive and requires treatment right away. CLL with an unmutated IGHV gene does not respond well to chemotherapy. It has a poor prognosis.
Protein levels in the blood or on the CLL cell
A protein level in the blood of less than 3.5 beta-2-microglobulin means a better prognosis.
Age
People 70 years old and older have a poorer prognosis.
Stage
CLL that is at a lower stage (stage 0 or 1) at the time of diagnosis has a better prognosis.
Performance status
People with a good
Sex
Men have a worse prognosis than women when diagnosed with CLL. We need more research and can't say at this time what the prognosis is for transgender, non-binary and gender-diverse people.
Lymphocyte doubling time
Lymphocyte doubling time is the time it takes for the lymphocyte count in the blood to double. CLL with a lymphocyte doubling time of more than 1 year has a better prognosis.
CLL International Prognostic Index (CLL-IPI)
The CLL International Prognostic Index (CLL-IPI) is a scoring system that combines information about these prognostic and predictive factors rather than focusing on the factors on their own:
- Rai stage 1 or greater (1 point)
- age greater than 65 (1 point)
- unmutated IGHV (2 points)
- the level of beta-2 microglobulin protein in the blood is greater than 3.5 (1 point)
- 17p chromosome deletion with or without the TP53 mutation (4 points)
These scores are added together to give doctors an estimate of the risk category. There are 4 risk categories: low, intermediate, high and very high.
The CLL-IPI helps you and your healthcare team make treatment decisions that are right for you. This index is also used in clinical trials testing new drugs to treat CLL.
| Risk category | CLL-IPI risk score |
|---|---|
| Low | 0 to 1 |
| Intermediate | 2 to 3 |
| High | 4 to 6 |
| Very high | 7 to 10 |