Despite advances that have made treatments safer and more effective, childhood cancer survivors don't appear to have experienced gains in long-term health outcomes, a new study suggests.
Their survival odds are better, but as adults they may have chronic medical problems linked to cancer and tumor treatments, the study found.
Up to one in four childhood cancer survivors report health problems in their 20s and 30s, researchers report in the Annals of Internal Medicine.
"They have chronic conditions at higher rates than siblings and the general population and they perceive their health as worse," said lead study author Kirsten Ness of St. Jude Children's Research Hospital in Memphis, Tennessee.
Childhood cancer survivors' "adverse health outcomes increase with age - like the rest of the population - but several decades sooner," Ness added by email.
Ness and her colleagues compared 14,566 adult survivors of childhood cancer treated in the 1970s, 80s and 90s to their siblings without a history of malignancies.
Over the past generation, there has been an overall reduction in radiation exposure and chemotherapy doses. Because the study includes survivors treated in a more recent era of more targeted and less toxic medicines, researchers expected survivors who were treated more recently to report better outcomes.
"We expected their perceived health to be better - but it was not," Ness said.
The proportion of survivors with severe, disabling or life-threatening conditions did go down, from about 33 percent in the 1970s to about 21 percent among those treated in the 90s.
But compared to people treated in the 70s, survivors from the 90s were more likely to report poor general health and cancer-related anxiety, the study found.
By the 90s, survivors of leukemia, a blood cancer, were more likely to report poor general health and survivors of osteosarcoma, a bone cancer, were more likely to report persistent pain.
Changes in radiation or drug doses over time weren't associated with changes in the proportions of cancer survivors reporting health problems, the study also found.
No matter when they were treated, survivors were also more likely to report poor health when they smoked, didn't exercise enough or were unusually underweight or obese.
Certainly, changes in treatment and survival outcomes over time may have allowed people who would have died from cancer in the 70s to live long enough to complain of other health issues in the 90s, the authors note.
It's also possible that some personal risk factors patients had for certain health problems might have preceded cancer, rather than being an outcome of tumors or treatment.
"While the quantity of survival has improved, it remains to be seen whether the quality of survival has improved," said Dr. Saro Armenian, director of the Childhood Cancer Survivorship Clinic at City of Hope Comprehensive Cancer Center in Duarte, California.
"Research on childhood cancer survivorship issues during the past two decades has highlighted the high burden of chronic health conditions in this aging population," Armenian, who wasn't involved in the study, added by email.
While it can be difficult for patients and families to focus on other health issues when their main concern is cancer, leading a healthy lifestyle with good diet and exercise habits may help minimize the risk of additional medical problems, said Dr. Joann Ater, of the childhood cancer survivor program at the University of Texas M.D. Anderson Children's Cancer Hospital in Houston.
Avoiding obesity, high cholesterol, and high blood pressure can decrease risk of cardiac side-effects and possibly second cancers, Ater, who wasn't involved in the study, said by email. She added, "Children should also participate in all preventive health measure such as not smoking or using tobacco, HPV vaccine, wearing sun screen to prevent skin cancer, and following recommended adult cancer screening, such as Pap smears for young women."