By Lisa Rappaport
(Reuters Health) - Adult survivors of childhood cancer who are exercise intolerant are also more likely to have mental health problems, a recent study suggests.
Researchers examined cross-sectional data on 1,041 adult survivors of childhood cancer as well as 286 community controls in the St Jude Lifetime Cohort. Overall, 634 survivors (60.9%) and 75 controls (26.2%) had exercise intolerance, defined as relative peak oxygen uptake of less than 85% of age- and sex-estimated levels for maximal cardiopulmonary exercise testing.
After adjusting for age at cancer diagnosis, age at assessment with cardiopulmonary exercise test, race/ethnicity, smoking, and physical activity, people with exercise intolerance were more likely than counterparts who didn't struggle with physical activity to experience anxiety (prevalence ratio rate 1.95), somatization (PRR 1.86), depression (PRR 1.31), and global emotional distress (PRR 1.50).
People with exercise intolerance were also more likely to be unemployed (PRR 1.76) and unmarried (PRR 1.33), and less likely to have a college degree (PRR 0.67).
In addition, exercise intolerance was associated with worse physical function (PRR 5.54), more bodily pain (PRR 2.14), and worse general health (PRR 2.31) after adjusting for treatment exposure and chronic health conditions.
"Exercise intolerance in childhood cancer survivors is associated with both cognitive outcomes, chronic disease and mortality, however, we did not specifically know how it impacted perceived well-being in daily life," said senior study author Kirsten Ness of St. Jude Children's Research Hospital in Memphis, Tennessee.
"This study indicates that exercise intolerance is associated with emotional health and with the survivor's own perception of their daily quality of life," Ness said by email.
Compared with childhood cancer survivors, community controls were more likely to be white (90.2% v 85.2%); younger (mean age 34.5 v 35.5 years); and to get at least 150 minutes a week of moderate intensity or vigorous physical activity (62.6% v 51.0%).
Community controls were also less likely to have cardiac (6.6% v 23%), pulmonary (7% v 30.4%), or neurosensory (5.2% v 25.7%) conditions.
Among adult survivors of childhood cancers, exercise intolerance was most prevalent among people with central nervous system tumors (81.5%), followed by bone (70.3%) and Wilms (58.8%) malignancies.
One limitation of the study is that researchers couldn't assess any temporal associations between exercise intolerance and social and emotional outcomes.
The analysis also didn't include information about childhood cancer survivors with the most impairments, and may underestimate the impact of exercise intolerance on emotional distress and social outcomes, the study team writes in JAMA Oncology.
Even so, the findings underscore how important it is for clinicians to consider the impact of exercise intolerance on patients' daily lives, said Dr. Jennifer Mack, an associate professor of pediatrics at Harvard Medical School and clinician at Dana-Farber Cancer Institute and Boston Children's Hospital.
"Clinicians can discuss the role of exercise tolerance in health-related quality of life with patients, encourage physical activity, and think collectively about ways to decrease the impact of treatment on exercise tolerance, while also maintaining cure rates for childhood cancer patients," Dr. Mack, author of an editorial accompanying the study, said by email.
"For patients who have experienced significant treatment toxicity and have limited exercise tolerance, there may also be a role for considering ways to promote physical activity in a way that is tolerable," Dr. Mack added. "All of this needs more study, but being aware of these findings and discussing them with patients is a great way to start."
SOURCE: https://bit.ly/2VsVL3w and https://bit.ly/2CWjqmN JAMA Oncology, online June 25, 2020.