A research team led by a St. Jude Children’s Research Hospital epidemiologist has conducted the largest analysis to date of how adult survivors of childhood cancer view their health risk. The scientists found that a surprisingly high number of survivors showed a lack of concern for their future well-being. The analysis of questionnaire data from 15,620 survivors found that 31 percent said they were not concerned about their future health and 40 percent were unconcerned about developing new cancers.

The finding is significant because advances in childhood cancer treatment have produced a growing number of long-term survivors, now numbering more than 420,000 in the U.S. alone. What’s more, these survivors are at increased risk of new cancers; other medical, cognitive and psychological problems; and death.

The researchers, led by Todd Gibson, Ph.D., of the St. Jude Department of Epidemiology and Cancer Control, published their findings in the scientific journal Cancer. The researchers drew on data from questionnaires administered to patients in the large-scale Childhood Cancer Survivor Study, in which the participants answer extensive questions about their attitudes and health status.

“The medical community has learned a lot about the risks faced by this group of survivors, but very little was known about how the survivors themselves perceived their risks of these late effects,” Gibson said. Previous studies had focused on the psychological impact of patients’ worries about such long-term issues, he said.

The researchers also compared the survivors’ responses to those from 3,991 siblings of survivors.

“This feature is a real strength of the analysis, in that we can assess whether the responses of the survivors are similar to those of siblings, who were like the survivors in most respects, but were not exposed to cancer and cancer treatments,” Gibson said. “So, we can hypothesize that any differences we see in the survivor group are related to this unique experience of cancer and cancer treatment.”

In fact, the researchers found that the siblings’ concern with their future health was only slightly lower, at 31 percent, than that of survivors. And, siblings’ concern about developing subsequent cancer was about the same.

“That similarity was really the major surprise in our findings,” Gibson said. “Despite the fact that survivors have such a greatly increased risk of both second cancers and other health problems, their perception of risk was not always commensurate with their actual risk.”

Gibson said his clinical colleagues were also surprised at the findings, especially given that they are so intimately involved in treatment and in communicating with patients. Gibson said he and his colleagues are unsure of the underlying cause for the lack of concern.

“At this point, we can only speculate, but the most obvious reason would be that survivors may not fully understand their risks,” he said, despite concerted efforts to educate patients about their treatments, future risks and how to minimize them. “We do know from prior studies that not all survivors are fully aware of the specific treatments they received and how those might increase their risks of late effects.”

“Other possibilities include that some survivors may actually be aware of their increased risks and choose not to be concerned,” he said. “Or, it may even be that some survivors are, indeed, following health guidelines and working with health care providers, leading to their lack of concern.”

Gibson said further research will seek to understand the motivations behind survivors’ lack of concern. Such studies will aim to understand whether the lack of concern is meaningful in terms of survivors’ health behavior. Further studies can also test the effectiveness of different educational approaches on survivors’ health concern and behaviors.

“If, however, survivors are aware, but not motivated or sufficiently aroused to be concerned, then more motivational education will have to be developed,” he said. “In any case, these findings offer a teaching point that we can use to emphasize to all survivors that they need to understand their risks.”

“These findings may also provide insight for the cancer survivorship community, that despite their considerable educational efforts, there may remain some subgroup of survivors that remain not particularly concerned about their risks of late effects.”