Study Finds Link Between Germ-Free Childhood And Leukemia

Two children with cancer walk down a hospital hallway.
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A paper published this past Monday in the journal Nature Reviews Cancer suggests that children who live in sterile environments and go on to suffer from infections later in life may be at risk for developing childhood leukemia, reported CNN.

The study looked at the most common of childhood cancers, acute lymphoblastic leukemia, discovering that the onset of the disease happens in two distinctive steps. The first step is a genetic predisposition that occurs before the child is born while the second involves being born into and raised in a germ-free environment and then going on to develop infections after being exposed outside of the home. The specific conclusion that the paper drew was that children who are exposed to cleaner households during their first year of life, coupled with little interaction with children outside the home, are more likely to be diagnosed with the cancer.

The cancer in question, also known as ALL, is a blood cancer that typically appears sometime during the first four years of life. It is an aggressive cancer that spreads quickly, making its way to other parts of the body including the lymph nodes, liver, and nervous system. Although a genetic predisposition plays a role in the development of the disease, only about one percent of those who have the gene mutation go on to develop it.

The author of the paper, Professor Mel Greaves from the Institute of Cancer Research, spoke about the findings, commenting that after reviewing more than 30 years of research, acute lymphoblastic leukemia might be more preventable than previously thought.

“This body of research is a culmination of decades of work, and at last provides a credible explanation for how the major type of childhood leukaemia develops. The research strongly suggests that (this cancer) has a clear biological cause, and is triggered by a variety of infections in predisposed children whose immune systems have not been properly primed.”

Previously, scientists believed that electromagnetic waves and other environmental factors were linked to the disease, although Greaves dismisses this possible correlation. The professor insists that research does not back up this prior claim and that any research with substantial findings includes studies looking at infection in early infancy.

Dr. Donna Lancaster, consultant pediatric oncologist at the Royal Marsden NHS Foundation Trust, cautions that further studies need to be done to determine if there are any specific infections linked to the development of the disease.

“There is no proven link yet with a specific infection. This [new study] still needs further investigation and any exposure of young children to infection has to be balanced with the risk of the infection.”