Seasonal Variation of Childhood Acute Lymphoblastic Leukaemia is Different Between Girls and Boys

Abstract

The aim of this study was to investigate seasonal trends in the incidence of acute lymphoblastic leukaemia (ALL) around the times of birth and diagnosis in children aged 0-4 years and also to examine gender specific effects. Children born in South Hungary during 1981-1997 were analysed. Registrations of first malignancies for children, diagnosed under age 5 years before the end of 2002 were obtained from the Hungarian Paediatric Oncology Group providing a representative sample of Hungarian children over a 17 year period of time. Data were available on the corresponding numbers of births for each month of the study period were obtained. Statistical analyses were performed using logistic regression with harmonic components. The study analysed 121 cases of children, aged under 5 years, who were diagnosed with ALL. We found no seasonal effect related to date of diagnosis. However, there was seasonal variability for ALL related to date of birth. Maximal rates were seen in children born in February and August in the simple harmonic regression model for all children diagnosed with ALL. Analysis by gender found evidence of seasonality related to month of birth with peaks in February and August in boys, but different seasonal effects were seen for girls (peak in November, nadir in May). Our study provides some evidence that male specific immune responses to infections around the time of birth could explain the male predominance in the incidence of ALL.

Clinical characteristics of acute lymphoblastic leukemia in male and female patients: A retrospective analysis of 705 patients

“…3), indicating that seasonality may affect the morbidity of ALL. However, controversy remains over the effect of seasonal factors in the incidence, diagnosis and treatment of ALL (7,24,29). Gao et al (12) performed an international survey in Singapore, the USA and Sweden to provide evidence for the seasonal diagnosis of ALL.…”

Exposure to Infections and Risk of Leukemia in Young Children

“…Four studies have suggested seasonal variation in births for leukemia, and three of the four have suggested that the birth peak occurs in late winter or spring(February (26), March (27), and April(28)), while the fourth suggested two distinct peaks in February and August(29). The variation seen in previous studies may be due to variations between community burden of infections between countries or variation in timing of infection seasons from year to year.…”

Perinatal risk factors for acute myeloid leukemia

“…Infectious etiologies have been hypothesized for both ALL and AML (9) because of the high incidence of these cancers in early childhood, coinciding with common early infections and immune system immaturity (10). This hypothesis has been supported for ALL by some (11–15) but not all (16–18) studies reporting associations with season of birth, a proxy for perinatal infectious exposures. However, season of birth has rarely been studied in relation to AML risk, and has never been examined in large population-based cohort studies with the potential to provide more robust and generalizable risk estimates.…”