Trends in Incidence of Childhood Lymphoma in Khon Kaen, Thailand, 1985-2008


Background: Lymphoma is the second most common of childhood cancer in Thailand, but data on trendsover time are limited.
Objective: To perform a statistic assessment of the incidence trend of childhood lymphomain Khon Kaen, Thailand, between 1985 and 2008.
Method: All children aged < 15 years newly diagnosed withlymphoma according to International Childhood Cancer Classification (ICCC) during January 1, 1985- December31, 2008 were collected from data base of Khon Kaen Provincial Registry. Aged-adjusted incidence rates (ASRs)were calculated by standard method and trends were calculated using the generalized linear model method, which utilizes incidence-rate-base logarithms.
Results: During 1985-2008 there were 72 children (47boys and 25 girls) who were diagnosed with lymphoma in Khon Kaen province. The peak age-group of diseasewas in the 5-9 year olds for both sexes. All cases were pathologically proven. Non-Hodgkin lymphoma (NHL)was more common than Hodgkin disease (ratio 7:1). The overall ASR was 6.04 per million (95%CI: 4.64 to 7.45)and the ASR was 7.64 per million (95%CI: 5.44 to 9.84) in boys and 4.37 per million (95%CI: 2.64 to 6.10) ingirls. Significant increases were observed for boys, since the 2006 to 2008 ASR was 15.3 per million (95%CI:5.73 to 25.0). Trend analyses during 1985 - 2008 showed that incidence among boys for lymphoma increasedby 1.38 percent per year (95%CI:- 4.6-8.3) while the incidence among girl decreased by 2.6 percent per year(95%CI:- 12-6.8).
Conclusions: Our data showed that the incidence of childhood lymphoma in Khon Kaenprovince was similar to the one of Thailand but lower than those of western countries. During the past 24 years,the incidence trend seems to be increasing in boys but decreasing in girls. Interpretation is difficult without abetter understanding of what underlies the reported changes.