Leukemia is the most common form of cancer in childhood. The term leukemia refers to cancers of the white blood cells, which are also referred to as leukocytes or WBCs. When a child has leukemia, large numbers of abnormal white blood cells are produced in the bone marrow. These abnormal white cells crowd the bone marrow and flood the bloodstream, but they cannot perform their proper role of protecting the body against disease because they are defective. Childhood leukemia accounts for about 30 percent of childhood cancers. Generally there are two types of leukemia, namely acute(tapidly developing ) and chronic(slowly developing) forms. In children about 98% of leukemias are acute. Acute childhood leukemias are divided into acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML), depending on whether specific white blood cells called lymphyocytes (or myelocytes).
There are several research ongoing in the area of childhood leukemia. Now the researchers at The Royal Melbourne Hospital and the University of Melbourne in Australia have found that targeting T cell, Acute Lymphoblastic Leukemia(T-ALL), may perk up treatments for this disease and help prevent relapse. According to the team, the discovery was made while studying mice prone to developing this leukemia. And with irradiation treatment in animal models, over 99 percent of cells in the thymus were killed. However, the stem cell-like cells persisted and rapidly recovered. This suggest that this cells may survive therapy and be responsible for relapsed disease following treatment.At present, the children with T-ALL are given extended therapy over two to three years in an attempt to stop a relapse. Further targeted therapy on the thymus cells could reduce the length and toxicity of treatment and prevent relapse.
The team was led by Dr Matthew McCormack and Dr David Curtis of the Rotary Bone Marrow Research Laboratories and the University’s Department of Medicine at The Royal Melbourne Hospital. Dr McCormack said, “The cellular origins of this leukaemia are not well understood. Our discovery that these cells are similar to normal stem cells explains why they are capable of surviving for long periods. It also explains why they are remarkably resistant to treatment.” “The identification of these cells provides an important target for the development and testing of new treatments for patients with T cell Acute Lymphoblastic Leukaemia.” said Dr Curtis, a Clinical Haematologist and head of the Leukaemia Research Program at The Royal Melbourne Hospital. The research was supported by the National Health and Medical Research Council of Australia, Cancer Council Victoria, Leukaemia Foundation of Australia and the Fight Cancer Foundation (BMDI). The research team aims to focus on novel treatments capable of killing these cells, which may lead to clinical trials within the next five years.