Led by specialists at the Department of Paediatrics at the National University Hospital (Singapore), doctors from Singapore and Malaysia have developed a personalised cancer treatment protocol which improves cure rate and decreases mortality by reducing the side effects of chemotherapy.
How does leukemia affect children?
Childhood Acute Lymphoblastic Leukaemia (ALL) is the most common form of cancer in children and affects three out of every 10 youngsters who are diagnosed in Singapore annually. It is a highly curable disease with intensive chemotherapy and the current cure rates in the developed world surpass 80%.
However, one of the significant side effects of the treatment is damage to organs like the heart, skin and brain, which may lead to long-term complications, including 2secondary cancers. In fact, the costs related to treating the side effects of chemotherapy often exceed those of treating leukemia.
Long term effects of chemotherapy
Conventional chemotherapy treatment for childhood ALL uses four drugs to achieve remission from cancer. This results in prolonged hospital stays, usually up to one month.
The increased complications add to the cost of therapy, and most importantly, put the young patients at a high risk of long-term side effects, which can be life threatening and significantly reduce quality of life.
Benefits of new treatment
The team at the National University Hospital (NUH) postulated that patients who responded well to the initial phase of treatment might be curable with less intensive chemotherapy.
Thus, they developed a cost-effective method to accurately measure the patient’s response to treatment. This allowed the majority of patients to avoid the most toxic therapy, which is reserved only for those who responded poorly and had the highest risk of having their leukemia return.
Promising test results
A total of 556 children under 18 years were recruited over a period of six years from 2003 to 2009 in this study, which is named Malaysia-Singapore (Ma-Spore) ALL 2003.
The new protocol, which starts with a three-drug remission-induction therapy, reduced the intensity of the treatment by 25%, compared to the conventional therapy given in most developed countries. The NUH doctors were able to develop a simplified yet accurate method to measure the amounts of leukaemia cells remaining in the body after therapy. By using this to guide treatment decisions, the doctors found that in up to 86% of children enrolled in the study, a significantly lower dose of chemotherapy could be given without comprising their long-term cure rate.
Treatment for ALL
ALL – is a cancer of the blood and bone marrow. This type of cancer gets worse quickly if it is not treated properly. It is the most common type of cancer in children. Unlike previous trials where patients typically stayed in the hospital for the first month of treatment, most patients in this study could be discharged and managed as outpatients within five days of diagnosis.
Associate Professor Allen Yeoh, Principal Investigator of the study and Senior Consultant, Division of Paediatrics Haematology-Oncology, NUH said, “Leukaemia treatment creates a conundrum. On one hand, leukaemia is a rapidly fatal cancer if not treated correctly. On the other hand, chemotherapy drugs cause significant side effects that worry both doctors and parents. By personalising the dose of the chemotherapy drugs, we were able to deliver the optimal doses to maximise each child’s potential for cure.”
Associate Professor Yeoh is also a Senior Consultant at the National University Cancer Institute, Singapore.
As a result, 81% of the patients were cured. For patients treated at the UMMC, this represents a 45% improvement in cure compared to their previous study. The Ma-Spore ALL 2003 study was the largest of its kind in the ASEAN region and findings indicate that the cure rates achieved are among the best in Asia and the rest of the world.
Hope for childhood leukemia patients
Associate Professor Tan Ah Moy, Senior Consultant, Haematology-Oncology Service at KKH said, “Many children in Singapore and Malaysia have benefited from this study, getting a good cure with reduced late effects caused by the chemotherapy.
Acute Lymphoblastic Leukemia is the commonest childhood cancer, and while science has an important role in administering the appropriate chemotherapy combination and monitoring the disease, we must not forget the significance of a holistic approach with psychosocial support in contributing to improved cure rates and success.
Continued collaboration among paediatric oncologists, as undertaken for this study, will continue to contribute to better management and addressing issues of childhood cancer that are unique to this part of the world.”