1 St. Jude Children's Research Hospital, Memphis, TN, United States.
2 Concordia University, Montréal, QC, Canada.
3 Fred Hutchinson Cancer Research Center, Seattle, WA, United States.
4 The Hospital for Sick Children, Toronto, ON, Canada.
5 University of Calgary, Calgary, AB, Canada.
6 National Cancer Institute, Rockville, MD, United States.
7 University of California, San Francisco, CA, United States.

Although survivors of childhood cancer are at an increased risk, little is known about the prevalence of chronic pain, associated interference, and daily pain experiences. Survivors (N = 233; mean age = 40.8 years, range 22-64 years; mean time since diagnosis = 32.7 years) from the Childhood Cancer Survivor Study completed pain and psychosocial measures. Survivors with chronic pain completed 2-week, daily measures assessing pain and psychological symptoms using mHealth-based ecological momentary assessment. Multivariable-modified Poisson and linear regression models estimated prevalence ratio estimates (PR) and mean effects with 95% confidence intervals (CI) for associations of key risk factors with chronic pain and pain interference, respectively. Multilevel mixed models examined outcomes of daily pain and pain interference with prior day symptoms. Ninety-six survivors (41%) reported chronic pain, of whom 23 (24%) had severe interference. Chronic pain was associated with previous intravenous methotrexate treatment (PR = 1.6, 95% CI 1.1-2.3), respiratory (PR = 1.8, 95% CI 1.2-2.5), gastrointestinal (PR = 1.6, 95% CI 11.0-2.3), and neurological (PR = 1.5, 95% CI 1.0-2.1) chronic health conditions, unemployment (PR = 1.4, 95% CI 1.0-1.9) and clinically significant depression and anxiety (PR = 2.9, 95% CI 2.0-4.2), as well as a diagnosis of childhood Ewing sarcoma or osteosarcoma (PR = 1.9, 95% CI 1.0-3.5). Higher pain interference was associated with cardiovascular and neurological conditions, unemployment and clinical levels of depression and/or anxiety, and fear of cancer recurrence. For male, but not female survivors, low sleep quality, elevated anxiety, and elevated depression predicted high pain intensity and interference the next day. A substantial proportion of childhood cancer survivors experience chronic pain and significant associated interference. Chronic pain should be routinely evaluated, and interventions are needed.