Patterns of distribution of childhood cancer in Africa.

BACKGROUND Very little is known about the regional variation in the incidence of childhood malignancies in Africa. The aim of the study was to perform a comprehensive analysis of the distribution of childhood cancer in Sub-Saharan Africa and compare the results to the Globocan estimations. METHODS A letter of invitation to participate was sent to all registry centers in Africa registered with the International Agency for Research on Cancer and to all African centers registered with AORTIC and SIOP Africa, requesting similar information as in CanReg 4. Childhood cancers were defined as those occurring below the age of 15 years. The data requested was from 2000 to 2010. The malignancies were classified and coded according to the International Classification of Childhood Cancer, 2004 system. Data obtained were analyzed using EpiInfo and Statistica 10 software. Information regarding the estimation of the numbers and incidence of the top 5 childhood cancers in specific countries was obtained from Globocan Web site. RESULTS There were 21 centers included in the study from 18 Sub-Saharan African countries. The data analyzed differed from center to center and included cases from 1985 to 2011. The proportion of childhood cancer out of all cancers ranged between 1.4% in Ghana to 10.0% in Rwanda. In Southern Africa, Kaposi sarcoma was the most common malignancy in children in Mozambique (15.8% of all cases) and the second most common in Zambia (15.6%) and in Malawi (12.4%). In Eastern Africa, Uganda recorded Kaposi sarcoma as the most common tumor in children (22.0%), while two Kenyan centers reported mainly Burkitt lymphoma (25.1 and 37.1%, respectively). In Central Africa, Congo classified retinoblastoma as the most common childhood cancer with an incidence of 20.1%. In Western Africa, Non-Hodgkin lymphoma was the most common in Ghana (53.6%), in Ivory Coast (73.6%) and in Mali (32.7%). Nephroblastoma remains the most common solid tumor in Africa exceeding 10% of total pediatric cancers in many countries (Rwanda 21.3%, Senegal 22%, Ivory Coast 14.5%, Mali 17.6%, Congo 15.5%, etc). CONCLUSION Unlike developed countries, lymphomas, nephroblastoma, Kaposi sarcoma and retinoblastoma were the most common pediatric tumors in Africa. Globocan estimations despite bringing significant contribution to the registration map cannot replace the data from local hospital and population-based registries. All efforts should be directed in developing functional and reliable childhood cancer registries across the African continent.