Childhood Cancer Survivors Are at Higher Risk for Gastrointestinal Cancers
Treatment advances have extended the lives of most children diagnosed with cancer into adulthood. Although this is a triumph over once deadly diseases, studies have suggested that childhood cancer survivors may develop gastrointestinal (GI) cancers more often and at an earlier age than the general population.
A new study* has confirmed these findings and identified many of the risk factors that contribute to secondary GI cancers. Tara Henderson, MD, MPH, assistant professor of pediatrics and director of the Childhood Cancer Survivors Center at The University of Chicago (UChicago) Medicine, and colleagues analyzed treatment and outcome data for 14,358 survivors of a range of pediatric cancers diagnosed before age 21. Not only were survivors developing GI malignancies at a rate nearly five times that of the general population, the cancers were appearing as soon as 5.5 years after the primary cancer diagnosis.
The results from the study, which was published in Annals of Internal Medicine, coincided with earlier findings suggesting that radiation exposure is a substantial risk factor for second cancers in cancer survivors. Those exposed to abdominal radiation were at the greatest risk–– 11.2 times that of the general population.
Yet, even study participants who did not receive radiation treatment for their primary cancer were at increased risk, which the researchers speculate may be related to a genetic predisposition. Independent of radiation exposure, treatment with high doses of procarbazine and cisplatin chemotherapies was also associated with secondary GI cancers.
Dr. Henderson said, “These findings will hopefully allow us to identify at-risk patients and implement better surveillance in clinical practice.”
The researchers indicated that curing the primary childhood cancer should always be the top priority, so they do not recommend altering existing treatment protocols to decrease the long-term risk for gastrointestinal cancers. However, newer effective therapies associated with a lower risk may be available for some diseases.
In addition, Dr. Henderson and her colleagues advise screening childhood cancer survivors for GI cancer earlier than current general guidelines, particularly among those with increased risk factors. They recommend this population be screened every five years, beginning 10 years after radiation treatment, or at age 35, whichever is later.
“We can’t yet predict which patients will face a subsequent cancer, but we can and should devise surveillance guidelines that take all the risk factors into account,” said Dr. Henderson. “Waiting until these patients are 50 is simply not enough.”
*This research study was supported in part by grant numbers U24 CA55727 and K07 CA134935 from the National Cancer Institute of the National Institutes of Health.