(NaturalNews) Adults who underwent chemotherapy as children are at a significantly higher risk of developing cancer as adults, according to a study conducted by researchers from the Institute of Cancer Epidemiology in Copenhagen, Denmark, and published in the Journal of the National Cancer Institute.
Researchers examined the medical histories of 47,679 people from Denmark, Finland, Iceland, Norway and Sweden who had been diagnosed with cancer before the age of 20 between the years of 1943 and 2005. They found that those diagnosed with a childhood cancer ran three times the risk of developing cancer in adulthood as an adult of the same generation who had not had cancer as a child. This elevated risk held strong even into old age.
The generation most likely to develop second cancers was that diagnosed between 1975 and 2005, followed by those diagnosed between 1960 and 1975 or those diagnosed before 1970. Because the doses used in radiation treatment have steadily decreased over the years, while chemotherapy treatment has become steadily more aggressive, the researchers concluded that childhood chemotherapy is the most likely culprit for the increased risk of adult cancers.
"What we need now is two-fold: new treatment ideas to decrease the risk of later effects, and much better surveillance of childhood cancer survivors during adulthood," lead researcher Jorgen Olsen said. "Cancer treatments don't just increase the risk of other cancers, but can lead to all sorts of other problems -- from cardiovascular to reproductive."
Pediatric oncologist James Nicholson of Addenbrooke's Hospital in Cambridge agreed that survivors of childhood cancers need to be carefully monitored for new cancers throughout their lifetimes.
"A study like this does raise awareness of the problem," he said. "If it means alarm bells ring earlier when there are symptoms in people who were treated for cancer as a child that would be a very good thing."