Childhood Cancer 2016
Can we reduce exposure to risk factors associated with childhood leukaemia and other cancers?
Dr Mark Miller - UCSF, San Francisco, USA
We’ve had an opportunity at this meeting to review the dramatic progress in treatment of childhood leukaemia which truly is spectacular and from the presentations that we’ve heard the progress continues to this day. What I’m talking about is potential contributors to the risk for getting childhood leukaemia. Wouldn’t it be wonderful if we could prevent just a fraction of those children that get childhood cancer and I believe that this is possible.
Could you tell us more about the study?
We conducted a survey of paediatric oncology providers in the United States to look at what their attitudes and practices were regarding potential exposures to environmental hazards and what their training was. One of the things that stood out was that the majority felt that environmental exposures were in fact important contributors to risk for childhood cancer. The vast majority said that they had questions from parents that they had to field about these exposures but more than half of them said that they were quite uncomfortable dealing with these questions. In addition, and quite hopefully, 92% said that they really would like to learn more about environmental health and contributors to childhood cancers.
What sorts of environmental factors have you looked at?
Ones that I’m most concerned about for which there’s the strongest level of evidence is exposure to air pollution and particularly traffic related air pollution; exposure to pesticides in the home as well as potentially occupational exposure to pesticides and tobacco smoking. Tobacco is an exposure issue for the father and includes the pre-conception time period, so we’re not used to thinking in terms of that, and tobacco control efforts have not highlighted the importance of young men who may in the near future be fathering children not smoking to reduce the risk of health consequences in their children.
In addition to risk factors that have been identified there are factors that are protective and one that’s particularly important to me is folate vitamin or vitamin supplementation with folate. We see women who have had a diet that’s high in folate or folate supplement in the very early period of pregnancy, before they usually go to see an obstetrician for healthcare, that if they receive that there’s a really significant reduction in risk of their children developing childhood leukaemia.
What do we do with this information?
We now have a stronger level of evidence than we have previously because of a large multinational collaboration, the Childhood Leukaemia International Consortium. This is a group of 23 studies from all around the world that have looked at childhood leukaemia and by pooling the data from all of these studies we’re able to have much stronger results and be able to look at more detailed specific populations that may be at risk and forms of leukaemia that are more rare than just the grouped overall leukaemia risk.
Moving forward, what I’d like to see is public health authorities beginning to address these exposures and reduction of these risks, exposures, in children. In fact, there are already programmes for a great many of these and we see that they are effective in some ways. For example, reductions in exposure to air pollutants in Los Angeles improved children’s growth of their lung function in childhood which translates to better lung function through life. Moving forward I’d like to see the paediatric oncology community at the table with these discretions. How do we move forward in ways that might benefit children’s health and how do we move forward in ways that can reduce exposures to things that we know are not healthy for children and the paediatric oncology community would be very helpful.