SUPPORT CANADIANS LIVING WITH CANCER
Prognosis and survival for multiple myeloma
If you have multiple myeloma, you may have questions about your prognosis. A prognosis is the doctor’s best estimate of how cancer will affect someone and how it will respond to treatment. Prognosis and survival depend on many factors. Only a doctor familiar with your medical history, the type, stage and characteristics of your cancer, the treatments chosen and the response to treatment can put all of this information together with survival statistics to arrive at a prognosis.
A prognostic factor is an aspect of the cancer or a characteristic of the person that the doctor will consider when making a prognosis. A predictive factor influences how a cancer will respond to a certain treatment. Prognostic and predictive factors are often discussed together. They both play a part in deciding on a treatment plan and a prognosis.
The following are prognostic and predictive factors for multiple myeloma.
People who have a lower stage of multiple myeloma usually have a better prognosis.
Younger people have a better prognosis than older people.
Blood test results
The results of certain blood tests are important in determining the prognosis for people with multiple myeloma.
Beta-2-microglobulin is a protein found on the surface of myeloma cells that plays a role in the immune response. A higher level of beta-2-microglobulin predicts a poor prognosis. The level of this protein goes up if:
- the number of myeloma cells goes up
- there is kidney damage
Albumin is the main protein in plasmaplasmaThe liquid part of blood that carries the blood cells. Plasma contains many proteins and minerals. that helps to maintain blood volume. A higher level of albumin predicts a better prognosis.
Lactate dehydrogenase (LD) is used to help understand how much cancer is in the body (called tumour burden). A higher level of LD predicts a poorer prognosis.
Creatinine is a waste product of muscle breakdown that is removed from the blood by the kidneys. Measuring the creatinine level shows how well the kidneys are working. People with multiple myeloma who have a high creatinine level have a poorer prognosis.
Doctors look at cells removed from the bone marrow to see if there are changes to the chromosomes. Some changes to chromosomes are linked to a poorer prognosis, including:
- a missing chromosome 13 (called a deletion)
- missing part of chromosome 17 (called a 17p deletion)
- a rearranged chromosome 14 (called a translocation)
- an extra copy of part of chromosome 1 (called a gain or amplification)
Risk stratification based on chromosome changes
Doctors can predict which people with multiple myeloma are most likely to have the best or worst outcome based on the number and type of chromosomal changes. This is called risk stratification. People will be told if they are good (low) risk, intermediate risk or high risk.
- good (low) risk – likely to survive 8 to 10 years
- intermediate risk – likely to survive 5 years
- high risk – likely to survive less than 2 years
People whose kidneys aren’t working well (functioning) have a poor prognosis. Doctors can measure the level of creatinine in the blood to see how well the kidneys are working.
Dialysis can help improve kidney function in people with multiple myeloma.
Plasma cell labelling index
The plasma cell labelling index (PCLI) measures how fast myeloma cells are growing in a sample of cells removed from the bone marrow. A high PCLI predicts that the myeloma cells are growing quickly and is linked to a poor prognosis.
Performance status is ranked on a scale of 0 to 4. A lower number indicates that a person is in better health and is able to be more active than a person with a higher number. Performance status is important in multiple myeloma because people who have a good performance status are able to withstand intensive treatments that may have a better outcome but have more side effects.
Response to treatment
People whose cancer responds well to treatment and go into complete remissioncomplete remissionA decrease in or the disappearance of signs and symptoms of a disease (such as cancer). have a better prognosis than people whose cancer does not respond to the initial treatment.
Gene expression profiling is a way for doctors to analyze many genes at the same time to see which are turned on and which are turned off. Doctors have found several abnormal gene patterns (called a genetic signature) in people with multiple myeloma. These genetic signatures are helpful in making a prognosis. Some genetic signatures are linked to a better prognosis and better response to treatment while other signatures are associated with a worse prognosis.