Evolution of paediatric oncology over the years: overview with a focus on sub-Saharan Africa and examples from the Kenyan experience.

In this paper on "The Evolution of Paediatric Oncology Over the Years", a historical perspective is outlined regarding the subspecialty of paediatric oncology on a global basis. The evolution of paediatric oncology units and their role in the progress of cancer management in children is highlighted. It is noted that success in the management of cancer in adults has followed the footsteps of breakthroughs and success in paediatric oncology. The epidemiology of cancer in children in sub-Saharan African and the development of paediatric oncology are also highlighted. The development of a paediatric oncology unit at the Kenyatta National Hospital in Nairobi, Kenya has been focused on, pointing out challenges, constraints and success that are associated in the initiation and nurturing of such units in developing countries. Lastly, Burkitt's lymphoma is singled out for discussion to illustrate problems that are abound in cancer management in children in sub-Saharan Africa.

PIP: Childhood cancers differ from adult cancers in the pattern and frequency of the various types; childhood malignancies may have different etiological factors of prominent genetic component and they respond to therapy better than malignancies in adults. Success in managing cancer in adults has followed breakthroughs in pediatric oncology. A historical overview is presented on a global basis of this subspeciality of pediatric oncology. Sections consider pediatric oncology units and data collection, the general management of pediatric tumors, and the treatment of pediatric malignancy in Kenya. The author specifically highlights the evolution of pediatric oncology units and their role in the progress of cancer management in children, and the epidemiology of cancer in children in sub-Saharan Africa. The etiology and care of Burkitt's lymphoma is considered as an example of the serious problems that may be encountered in managing cancer in children in sub-Saharan Africa. The experience of developing a pediatric oncology unit at Kenyatta National Hospital in Nairobi, Kenya, is also cited as an example of the challenges, constraints, and successes associated with such activities in developing countries. Finally, while much progress has been made in the field of pediatric oncology, further advances remain to be made.

Childhood aplastic anaemia in Kenya.

Forty two children with aplastic anaemia were seen at Kenyatta National Hospital, Nairobi, over a period of 8 years (1980-1988). These have been analysed with respect to sex, age and area of geographical origin. The overall male:female ratio is 1:1 with a preponderance of Kikuyu patients. Repeated transfusions was the commonest presenting feature and rapid onset was associated with poor prognosis. Exposure to herbicides/pesticides and other agrochemicals is implicated in the aetiopathogenesis of childhood aplastic anaemia in Kenya.

Malnutrition and infections as causes of childhood anemia in tropical Africa.

Anemia is the most common disorder in hospital patients in tropical Africa, and it is demonstrated in up to 70% of inpatients. Community studies indicate that as many as 40% of the children younger than 15 years of age, 63% of these being younger than 3 years, are anemic. Although the anemia is multifactorial in etiology, the interplay between malnutrition and infection is still the most important element in causing the morbidity and mortality attributed to childhood anemia in Africa. Although iron deficiency is the most common cause of nutritional anemia, P. falciparum malaria is the leading cause among the anemias of infectious origin. The role of other causative agents is highlighted in the discussion. The fact that effective treatment depends on accurate diagnosis is also emphasized.

Childhood Leukaemia: Is it a Problem in Tropical Africa?

This is a report on the frequency and biogical aspects of childhood leukaemia in tropical Africa based on experience from Kenya and the literature. Out of the 934 cases of leukaemia diagnosed, treated and followed up at Kenyatta National Hospital between 1976 and 1985, 347 occurred in children below the age of 15 years and comprised 37% of leukaemia in all ages. Childhood acute leukaemia formed 52.3% of all the acute leukaemias. Acute non-lymphocytic (ANLL) and acute lymphocytic leukaemias (ALL) occurred. in almost equal proportions 42 % and 46 % respectively. FAB ANLL, M4 and FAB, ALL, L1 subtypes predominated although ALL, L2 (45%) was encountered almost as frequently as ALL, L1 (50%). The acute leukaemias had a peak occurrence in the 5-9 age group at a median frequency of 41 74. These observations are generally true for childhood leukaemia patterns in sub-Saharan Africa. T-cell ALL phenotype was the most commonly diagnosed, being 46'x of ALL. Clinically advanced disease, severe malnutrition and common ocular chloromata were notably prominent. Remission induction and survival results were noted to be inferior to those obtained in Western countries and are attributed to the presence of many risk factors and unsatisfactory management facilities.

The role of needle aspiration cytology in the differential diagnosis of accessible paediatric tumours.

In the period 1985-88, 171 fine needle aspirates from paediatric patients with malignant and non-neoplastic masses were processed and evaluated in the Department of Haematology, Kenyatta National Hospital, Nairobi. Sixty-five needle aspirates had the diagnosis corroborated by histological reports. The rest had relevant clinical and laboratory information to support the cytological diagnosis. The histological diagnosis confirmed cytological diagnosis in 100% for neuroblastoma, 96% for Burkitt's lymphoma, 75% for carcinoma, 68% for sarcoma cases, 53% non-Hodgkin's lymphoma and 50% for Hodgkin's lymphoma. There were no false positives. It is therefore concluded that fine needle aspiration is a useful tool. It may obviate diagnostic surgery, help in planning the course of management of patients and it is diagnostic in Burkitt's lymphoma and neuroblastoma. Fine needle aspiration cytology is an easy, cheap and quick investigation compared to surgical biopsy.

Ultrastructure of bone marrow in patients with visceral leishmaniasis.

Ultrastructural studies were performed on bone marrow aspirates from three patients with visceral leishmaniasis. The patients were moderately anaemic but showed a suboptimal increase in the absolute reticulocyte count. Serum and red cell folate concentrations and serum vitamin B12 concentrations were normal in all three cases, and serum ferritin concentrations were normal or increased. The bone marrows were hypercellular and showed erythroid hyperplasia; a high proportion of the erythroblasts showed dyserythropoietic changes. Amastigote forms of Leishmania donovani were found within bone marrow macrophages and within occasional neutrophil and eosinophil granulocytes. Electron microscopy showed the presence of many abnormal cells, which probably represented immature erythroblasts with giant lysosomes. These cells were often large, usually contained immature nuclei with relatively little condensed chromatin, had 1-20 electron dense cytoplasmic granules with an average diameter of 0.5 micron, and regularly displayed substantial rhopheocytotic activity. A few abnormal cells and intermediate and late erythroblasts appeared to have been phagocytosed by macrophages. The data indicate that dyserythropoiesis and ineffective erythropoiesis have a role in the pathogenesis of the anaemia of at least some cases of kala-azar.

Possible viral etiology of childhood acute lymphosarcoma-cell leukaemia in Kenya.

Childhood acute lymphosarcoma-cell leukaemia (CALSCL) accounts for 13-14% of all childhood leukaemias in Kenya. It occurs in temporal clusters in children aged 5-9 years, and an environmental leukaemogenic factor is therefore suspected. A study of children with acute leukaemia was carried out, and suggested that CALSCL is a specific clinical entity amongst the acute lymphocytic leukaemias. Whether human T-cell leukaemia virus (HTLV) may play a role in its etiology remains to be determined.