Of the excess of mortality and the cause of death in the remains
In addition to the importance of potentially modifiable risk factors, this report is the first to demonstrate that the primary causes of death in long-term survivors are similar to the primary causes of death in the US population, previously occurring in survivors.
“We identified that long-term survivors of childhood cancer experience a large number of deaths in excess of what would occur for the general, aging population,” said first and corresponding author Stephanie Dixon, MD, MPH; St. Jude Department of Oncology. “We are the first to find that decades after treatment, these excess deaths are prevalent from the same leading causes of death as in the general population, including secondary cancers, heart disease, cerebrovascular disease/stroke, chronic liver and kidney disease, and infectious diseases. experienced at a younger age and at an older age, surviving childhood cancer,” Dixon said.
Treatments for childhood cancers have improved to the point where over 85% of US patients are effectively cured of their first tumor after frontline treatment. As more patients overcome their childhood cancer, the number of adult survivors is increasing. Comparing the CCSS cohort to the general population, researchers found that decades after treatment, survivors still experienced four times the expected risk of death.
The largest group of cancer survivors supports the discovery
Researchers were able to understand the problems that affected survivors using detailed health data from thousands of CCSS participants. The CCSS is the largest cohort of cancer survivors in North America, representing an estimated 20% of all childhood cancer survivors in that country. Scientists have been able to take this huge file of data to statistically calculate the variables affecting the mortality rate of the survivors. The group showed that even when common confounders, such as sociodemographic characteristics, were controlled, the difference in mortality between survivors and the general population persisted, but the protective effect of healthy life.
“What was most exciting to see was that, independent of prior treatment and sociodemographic factors, a healthy lifestyle and the absence of hypertension or diabetes were each associated with a reduced risk of health-related mortality,” Dixon said. “This suggests that while continued efforts to reduce the intensity of treatment, maintaining (or improving) 5-year survival are required, future research should also focus on interventions for modifiable lifestyle and cardiovascular risk factors, which can be specifically targeted at residuals with the goal of reducing the development of chronic disease and the developmental course of childhood cancer survivors.
Intensive treatments continue to tax the remnants of childhood cancer
Patients treated with more intensive therapies continued to experience higher mortality than the remaining survivors. Much research has focused on minimizing the harm of the therapy, but many survivors were treated with CCSS before the improved technique was popularized. This study shows that clinicians and researchers need to consider interventions that can reduce risk for the vulnerable population of survivors who were treated with aggressive therapies in their youth.
“Childhood Cancer Survivorship Research continues to provide key insights into the long-term outcomes of the growing number of children treated for cancer,” said co-author Leslie Robison, emeritus. St. Jude Department of Epidemiology and Cancer Control chair. “The findings from the current analysis need to be further emphasized in order to increase our efforts to reduce acute, chronic and late toxicities of treatment, especially those toxicities that directly or indirectly result in premature mortality.”
Authors and funding
The other authors of the study are Matthew Ehrhardt, Kirsten Ness, Kevin Krull and Yasui Yutaka, cf. St. Jude; Qi Liu, University of Alberta; Eric Chow and Wendy Leisenring, Fred Hutchinson Cancer Research Center; Kevin Oeffinger, Dean of the University; Paul Nathan, Hospital for Sick Children, University of Toronto; and Rebecca Howell, The University of Texas at MD Anderson Cancer Center and Ann C. Mertens, Emory University School of Medicine.
The study was supported by grants from the National Cancer Institute (CA55727); St. Jude Children’s Research Hospital Cancer Center Support (CORE) grant (CA21765) and ALSAC, a foundation and awareness organization St. Jude.