There were found out the connections of the activity of the Sun and smoke of forest fires with the incidence of various forms of benign and malignant neoplasms in the population of young children 0-4 years old, in Khabarovsk Region, Russia. Thus, it was determined that so-called "sporadic" fluctuations in the incidence of neoplasms in the child population are not random. They are caused by long multi-year cycles of changes in the complex of environmental factors. The authors identified this phenomenon as "Alternative oncogenesis", meaning by it the predominant occurrence of various forms of neoplasms in a certain period of time due to a change in the parameters of the complex of environmental factors. A proposed hypothesis is: ecologically linked oxidative stress as a cause of the epigenomic modulation leading to an imbalance between semaphorins and integrins that brings to oncogenesis. © The Authors, published by EDP Sciences, 2020.