Medical experts, studying childhood cancer statistics, are becoming increasingly convinced that common infections affecting mother and baby could play a key role in triggering certain diseases. The researchers, led by Dr Richard McNally from the University of Newcastle upon Tyne, analyzed cancer cases diagnosed in young children and found that a pattern emerged where two types of cancer - leukemia and brain tumors - repeatedly occurred at similar times and geographical locations.
This "clustering" pattern of cases is typical of diseases caused by infection, leading the researchers to speculate that outbreaks of infectious viruses could be a contributory cause of cancer. The researchers say that environmental factors can be discounted as they tend to produce clusters of cases in one place over a much longer time period.
"We found that place of birth was particularly significant, which suggests that an infection in the mother while she is carrying her baby, or in a child's early years, could be a trigger factor for the cancer. These could be minor, common illnesses that are not even reported... such as a cold, mild flu or a respiratory virus," said Dr McNally.
But Dr McNally added that people should not worry about "catching cancer", as the infection is only likely to lead to cancer in a very small number of individuals who are already genetically susceptible. "[Infections] would only lead to cancer in individuals who already carry mutant cells in their body. The virus would hit this mutant cell and cause a second mutation, prompting the onset of cancers like leukemia or brain tumors," he explained.
Cancer Research UK's medical director, Professor John Toy, said people should be cautious about interpreting the study's results. "These findings provide more clues to a link between viruses and some types of childhood cancer, but we need more evidence before we can be sure. Reassuringly for moms, children who are introduced to day-care or who are more socially active during their first year of life have been found to be at lower risk of childhood leukemia. This may be because their immune systems have been strengthened by being exposed to a wide variety of infections at an early age," he noted.
Source: University of Newcastle upon Tyne
