Changing patterns of acute lymphoblastic leukaemia in Nigeria

An increase in the number of Nigerian patients with acute lymphoblastic leukaemia (ALL), relative to those having acute myelogenous leukaemia, was predicted some years ago. This was expected to result from an enhanced socio-economic status of most members of the general population and improved nutrition. A review of the features of ALL patients seen in University College Hospital, Ibadan, during different periods over the past three decades revealed not only the predicted changes but also an increasing proportion of pediatric and female patients. Except for an unusual number of patients with the rare L3 morphological variant seen within the last 2 years, little else changed in the clinical and laboratory features of the disease. Atrophy of the thymus resulting from malnutrition is thought to inhibit the occurrence of common-ALL in the first decade of life. This inhibition is removed by improved nutrition, thus allowing more cases of common-ALL to develop in children. The trend in Nigeria has been observed earlier among Arabs in the Gaza Strip in the Sinai Peninsula. If the hypothesis is correct, undernutrition occurring for a long enough time in a previously well-nourished population should lead to changes opposite to those observed. The increasing percentage of patients who are either young, female or of high socio-economic class imply better prognosis for more Nigerian ALL patients.