Ecological factors associated with fluctuations in the incidence of neoplasms in children

Introduction: Despite the increasing volume of knowledge on oncogenesis, the year-to-year fluctuations in the incidence of neoplasms remain poorly explained. Neoplasms in children <5 years have primarily prenatal origin. However, the number of studies form Russia on this topic is limited. Aim: To study associations between fluctuations in the incidence of neoplasms among children <5 years and selected environmental factors (EF). Methods: Firstly, we studied associations between the overall incidence of malignant-(MT) and benign tumors (BT) in the 11 cohorts of under 5 children born in 1976-1986 in the city of Khabarovsk using Pearson’s correlation coefficients with lags from-3 to +3 years. Secondly, we studied correlations between specific forms of BT and MT with EF in the 17 cohorts in the Khabarovsk region. Thirdly, we assessed correlations between solar activity and the incidence of non-Hodgkin lymphomas (NHL) in 0-14 years old children 0-14 in Russia over 22 years (1997-2018). Results. An inverse correlation (r =-0.705, p = 0.015) was observed between the incidence of BT and MT in cohorts 1 year older sug-gesting that their fluctuations were in an antiphase. In cohorts with greater incidence of BT the incidence of MT was lower and vice versa. Significant correlation between the solar activity with lag 1 and the incidence of non-Hodgkin lymphomas (NHL) was observed in the 17 cohorts of children in the Khabarovsk Territory (r = 0.644, p = 0.032). Corresponding correlation coefficient for the 0-14-year-old children using national data was 0.621, p = 0.010 with a lag of 5 years. Conclusions. Annual fluctuations in the incidence of BT and MT are unlikely to be completely sporadic. An inverse association between the incidence of BT and the incidence of MT was observed potentially reflecting an alternative scenario of oncogenesis in these diseases influenced by a constellation of environmental factors. © 2021, Northern State Medical University. All rights reserved.