Impact of the environment on childhood cancer clinical outcomes.

Incidence rates of several childhood cancers have increased in the past decades in high- and middle-income countries, and epidemiologic studies worldwide have documented the important role of several environmental factors contributing to these trends, such as sources of air pollution and pesticides. What is less known is whether these chemicals also affect clinical outcomes in childhood cancer patients and survivors, via biological pathways involving DNA damage, epigenetic changes, oxidative stress, pro-inflammatory and immune responses which may operate across the cancer continuum from etiology, response to treatment, survival and survivorship. Despite overall improvement in cancer cure rates, children of color and underserved backgrounds still experience poorer prognosis than their white and affluent counterparts. While social determinants largely explain these observations, the independent effect of chemical exposures is not well-characterized. Drawing from adult studies, we present emerging evidence from epidemiologic childhood cancer studies on the impact of pre- and post-natal exposures to ubiquitous chemicals such as tobacco smoke, traffic-and industry-related air pollution, and pesticides on the health of childhood cancer patients and survivors. Data presented in this review provide the foundation to consider integrating environmental health into the treatment plan for childhood cancer patients and survivors, alongside other known therapeutic and modifiable prognostic factors.