Researchers found that the presence of residual traces of cancer was linked to poorer outcomes – suggesting that thalidomide’s effects could have real benefits for patients. Thalidomide’s side-effects mean its uses will be limited, but in patients who are ill with cancer it can be a very useful treatment.
Scientists at The Institute of Cancer Research, London, carried out detailed analysis of blood samples from more than 800 myeloma patients. The patients had received various treatments as part of the Myeloma IX clinical trial, run by the Medical Research Council (MRC). The team used a sensitive test to detect very low levels of residual, abnormal plasma cells in the patients’ blood samples.
Patients without residual cancer cells in their blood lived for longer than for those with even a very low number of abnormal cells - regardless of whether patients had been on more or less intensive treatment regimes. And researchers found that residual disease was much more likely to have disappeared in patients who had been receiving thalidomide, who were also less likely to see a return of residual disease. The numbers of patients were small, but significant.
Myeloma is a cancer of the immune system, accounting for around 1.5 per cent of cancer cases diagnosed each year in the UK. In myeloma, plasma cells in the blood grow uncontrollably in the bone marrow and become stuck there, disrupting normal blood cell production. Effective, proven treatments include stem cell therapy, and several other drugs, as well as thalidomide, but the new study showed that current treatments other than thalidomide often fail to completely get rid of residual disease.
The research also suggested that a blood test for residual traces of disease could predict which patients would live longest after treatment for myeloma, and that this could in future become an important part of routine care.
Study leader Professor Gareth Morgan, Professor of Haematology at The Institute of Cancer Research (ICR) and Head of the Myeloma Unit at The Royal Marsden NHS Foundation Trust, said: “Our study showed the benefits of maintaining thalidomide treatment in myeloma patients after standard treatment regimes have been completed, and even when symptoms have disappeared. It also showed that residual traces of myeloma are linked with poorer outcomes over time for patients.”
“Our study used data from patients in the Myeloma IX study, a now completed clinical trial funded by the MRC. It underlines the long-term importance of that original investment from the MRC, which is still helping us to make new discoveries that will benefit future patients with myeloma.”
The study was published in the Journal of Clinical Oncology. Professor Morgan’s team recently also published another study, which could lead to new tests to help work out which treatments are most suitable for individual myeloma patients.