Malignant disease - Leukaemia

Question 1

Malignant disease in children

Answer 1

• Uncommon, but affects 1 in 500 by 15 years of age
• The overall 5-year survival rate is 75%
• Presents with a localised mass or its pressure effects or disseminated disease
• Treatment may involve chemotherapy, surgery, radiotherapy or high-dose therapy with bone marrow rescue
• Fever with neutropenia must be investigated and treated urgently
• Measles and varicella zoster infection are potentially life-threatening
• Requires a multidisciplinary team to provide supportive care and psychosocial support
• Supportive care – includes not only management of side-effects but also pain management and fertility preservation
• Psychosocial support – includes not only the patient and parents but also siblings and other family and community members.

Question 2

Leukaemia

Answer 2

• Acute lymphoblastic leukaemia (ALL) accounts for 80% of leukaemia in children.
• Most of the remainder is acute myeloid/acute non-lymphocytic leukaemia (AML/ANLL). Chronic myeloid leukaemia and other myeloproliferative disorders are rare.

Question 3

Leukaemia (ALL)

(Acute lymphoblastic leukaemia)

Investigations

Answer 3

• Full blood count – in most but not all children, the blood count is abnormal, with low haemoglobin, thrombocytopenia and evidence of circulating leukaemic blast cells
• Bone marrow examination is essential to confirm the diagnosis and to identify immunological and cytogenetic characteristics which give useful prognostic information.
• Chest X ray is required to identify a mediastinal mass characteristic of T-cell disease.
• Immunological phenotyping further subclassifies ALL; the common (75%) and T-cell (15%) subtypes are the most common. Prognosis and some aspects of clinical presentation vary according to different subtypes, and treatment intensity is adjusted accordingly

Question 4

Leukaemia

Management of acute lymphoblastic leukaemia

Answer 4

• A number of factors contribute to prognosis in ALL and dictate the intensity of therapy

Remission induction

Before starting treatment of the disease, anaemia may require correction with blood transfusion, the risk of bleeding minimised by transfusion of platelets, and infection must be treated

Intensification

A block of intensive chemotherapy is given to consolidate remission. This improves cure rates but at the expense of increased toxicity

Central nervous system

Cytotoxic drugs penetrate poorly into the CNS. As leukaemic cells in this site may survive effective systemic treatment, additional treatment with intrathecal chemotherapy is used to prevent CNS relapse.

Continuing therapy

Chemotherapy of modest intensity is continued over a relatively long period of time, up to 3 years from diagnosis. Co-trimoxazole prophylaxis is given routinely to prevent Pneumocystis carinii pneumonia

Treatment of relapse

High-dose chemotherapy, usually with total body irradiation (TBI) and bone marrow transplantation, is used as an alternative to conventional chemotherapy after a relapse