Better Prognosis for Leukaemia
First Published: Enews - February 2012
The FMC Foundation has just given a grant to a project investigating the immune system's role in chronic myeloid leukaemia (CML) to determine which patients can safely stop their treatment without relapse.
CML is a blood disease where the bone marrow produces too many white cells. In the early stages of the disease the symptoms are often mild, but without treatment CML can transform to acute leukaemia.
It is treated by drugs such as imatinib, which can kill the cancerous cells and keep the disease at bay but which often causes a range of mild side effects that can affect a person's quality of life.
Dr David Ross from the Department of Haematology and Genetic Pathology says CML patients whose tests indicated no detectable leukaemia had the opportunity to come off imatinib as part of a clinical trial run by the Australasian Leukaemia & Lymphoma Group.
Some of the patients who entered the study have now been in remission without any treatment for more than 5 years. However, some patients relapsed within a few months of stopping treatment.
"In the clinical trial that we began in 2006 we have found that the CML came back in 60 per cent of patients who ceased treatment," Dr Ross said."These patients re-started imatinib and brought the disease under control again."
"This indicates that the cancer often remains in patients at very low levels even if it is undetectable in the routine blood test," he said.
Together with Lesley Snell from Genetic Pathology and Dr Peter Macardle from Immunology, Dr Ross hopes to determine why the cancer reappears in some patients and not others. He believes differences in the immune response to CML may offer an explanation.
"People traditionally haven't thought of response to imatinib involving the immune system," Dr Ross said. "We want to investigate whether the immune system is suppressing the low levels of cancer and preventing it from returning."
The new grant will allow the team to determine whether the presence of particular types of immune cells can influence whether patients are at lower risk of relapse.
"Being able to inform patients whether or not they can come off the drug without worrying about relapse will improve their quality of life, and could save considerable costs to the healthcare system," Dr Ross said.
He said the research will also inform future projects which could improve treatment for leukaemia.
"If we can determine whether the immune system plays a role in the regulation of CML we may also be able to stimulate this immune response against leukaemia by strategies such as vaccination," he said.