Incidence and frequency rates of childhood cancer in Namibia.

OBJECTIVE To estimate the extent of paediatric malignancy in an African country and to compare these findings with paediatric cancer rates in other countries. DESIGN A retrospective descriptive study which calculated incidence and frequency rates from the data obtained from a 6-year survey of childhood cancer in Namibia. SETTING Children from the general community who were referred by primary care physicians or clinics and diagnosed in peripheral district hospitals or a tertiary care institution. PATIENTS A total of 163 children less than 15 years of age diagnosed with any malignant neoplasm, intracranial tumour or histiocytosis between 1983 and 1988. INTERVENTION None. MAIN OUTCOME MEASURES The minimum overall incidence of childhood cancer recorded in Namibia was lower than the rates usually reported by economically privileged countries. The rates of certain malignancies corresponded to the rates recorded in other African countries. RESULTS The overall incidence of childhood cancer was 55.5 per million. Tumours of the central nervous system occurred most commonly (18%), followed by renal tumours (14%), leukaemia (12%) and lymphoma (11.5%). The 5.8 per million incidence rate of retinoblastoma was similar to the rates recorded in other African countries but higher than in the UK or the USA. The incidence rates per million children for renal tumours, malignant bone tumours and soft-tissue sarcomas were 7.4, 4.8 and 5.2, respectively, which correspond with the rates in Western Europe and the USA. The incidence rate of CNS tumours was only 9.3 per million. Both leukaemia (6.5 per million) and lymphoma (6.3 per million) had rates far lower than those recorded in central Africa or developed Western countries. CONCLUSION The incidence pattern of childhood cancer in Namibia demonstrates features of both the patterns described as typical for Africa and those described for industrialised countries.