Accelerated Aging: A Challenge to Childhood Cancer Survivors

By Thomas Crocker
Saturday, October 1, 2016

Childhood cancer survivors living with chronic conditions as adults may experience a kind of accelerated aging due to the late effects of cancer treatment. However, survivors with no chronic conditions enjoy a quality of life similar to that of individuals with no history of cancer, according to a recent study.

The American Childhood Cancer Organization estimates nearly 16,000 children younger than age 19 are diagnosed with cancer each year in the United States. Improvements in diagnosis and treatment mean more than 80 percent of these children can expect to survive at least five years after diagnosis, but they typically face a new challenge: coping with a long-term illness. The rate of childhood cancer survivors who develop at least one chronic condition may exceed 90 percent, according to the National Cancer Institute. This patient population is susceptible to a variety of treatment-related diseases, researchers have found, including heart disease, endocrine dysfunction, kidney disease, and musculoskeletal and cognitive abnormalities.

Young and hurting

Lisa Diller, MD, Chief Medical Officer of the Dana-Farber Boston Children’s Cancer and Blood Disorders Center and Professor of Pediatrics at Harvard Medical School, and Jennifer Yeh, PhD, a research scientist in the Center for Health Decision Science at Harvard University’s T.H. Chan School of Public Health, led a team of 10 investigators who quantified the effects of chronic conditions on childhood cancer survivors’ well-being using a summary measure of health-related quality of life. They compared the results with those for individuals in the general population. The findings appeared in the Journal of the National Cancer Institute.

The researchers compared 7,105 childhood cancer survivors and 372 of their siblings from the Childhood Cancer Survivor Study cohort with 12,803 individuals in the general population from the Medical Expenditures Panel Survey. Based on participants’ self-reported information, the researchers used a standardized measure of health-related quality of life to assign them a utility score ranging from 0, representing death, to 1, signifying perfect health.

“Our study is the first to use an overall measure of health to understand how health-related quality of life may vary between survivors of childhood cancer and individuals without a history of cancer,” says lead author Yeh. “We found that survivors with chronic conditions had lower quality of life than individuals in the general population. In contrast, survivors without any chronic conditions were similar [to the general population] in terms of well-being. This is encouraging for the latter set of survivors.”

Childhood cancer survivors had an average utility score of approximately 0.77, whereas the average score for siblings and individuals in the general population was about 0.81. Most strikingly, young survivors’ scores resembled those of people in the general population who were decades older.

“Most clinicians who see 18-year-olds in clinic wouldn’t think about screening them for chronic conditions. Young adult childhood cancer survivors ... may have a spectrum of health issues that approximate [those of] people in their 30s or 40s. Clinicians can’t always use chronologic age as a basis for treatment decision-making in these patients.”
— Eric chow, md, MPH, Medical Director of the Cancer Survivorship Program at Seattle Children’s Hospital

“Normal people, as they age, see their utility scores go down; they get more aches and pains and are less and less able to do things independently,” says Dr. Diller, the study’s senior author. “The utility scores we observed in a relatively young population of patients, 18 to 29 years old, were comparable to those of individuals in the general public ages 40 to 49. What we saw that most impacted the utility score was the presence or absence of chronic illness that we assume is related to participants’ childhood cancer. Most 18- to 29-year-olds don’t have chronic illnesses.”

When researchers looked at survivors who didn’t report chronic illnesses, their utility score was right for their age.

“If you don’t get a chronic illness as a result of your childhood cancer treatment, the fact you had cancer in and of itself doesn’t change your health-related quality of life,” Dr. Diller adds. “You don’t see yourself as a debilitated person. This is a nice message because it gives me my charge to help find therapies for childhood cancer that result in as good cure rates as we have now but with fewer chronic illnesses in the future.”

One Problem, Many Solutions

For clinicians, crafting treatments for childhood cancer that cause fewer sequelae is one important way of addressing the problem of therapy’s late effects. Another is ensuring survivors are aware of the increased risks they face for chronic conditions. To start the conversation, clinicians may wish to gauge how much survivors know about their former malignancy and its treatment. The literature suggests a dearth of such knowledge among survivors because of their youth at the time of treatment and a historical lack of emphasis among providers on informing patients about their treatment and its possible late effects, according to Eric Chow, MD, MPH, Medical Director of the Cancer Survivorship Program at Seattle Children’s Hospital. Dr. Chow advocates better patient information and communication.

“We think, for example, there is a fair number of young adult survivors who have borderline hypertension and maybe borderline diabetes who probably aren’t being screened or treated as aggressively as they should be,” says Dr. Chow, who was not involved with the above study. “One proposal is to see if we can enhance treatment of these conditions [in this patient group] because we know they predispose to heart disease later on.”

Dr. Diller suggests clinicians also need to be better informed.

“As [childhood cancer survivors with chronic conditions] age, they’re sort of prematurely aging,” she says. “They may need the type of health care older people get as they age. Survivors can’t be cared for by pediatric oncologists. The appropriate thing is for them to be cared for by primary care physicians and internists, but these clinicians need specialized literature that helps them understand the differences between a 29-year-old survivor who says he can’t walk up stairs versus a 29-year-old [with no history of cancer] who says he can’t walk up stairs. The non-survivor may just need to exercise. The survivor may have heart disease.”