Childhood cancer survivors have a significantly higher risk of suicidal ideation compared with their peers without cancer, according to a systematic review and meta-analysis.

Led by Jia Yang Tan of the Yong Loo Lin School of Medicine at the National University of Singapore, the researchers analyzed 16 studies published from January 1, 2000, to November 17, 2024, and found that while the prevalence of suicide among childhood cancer survivors (CCSs) was 0.30%, suicidal ideation (SI) was reported in 9% of cases, with an increased relative risk (RR) of 1.67 (95% confidence interval [CI] = 1.39-2.01) compared with controls. The study followed PRISMA guidelines with prospective PROSPERO registration.

In the meta-analysis, which included 148,869 participants for suicide prevalence and 20,140 for SI, researchers did not find a statistically significant increase in suicide risk among CCSs compared with controls (RR = 1.50, 95% CI = 0.63-3.62). However, subgroup analyses suggested that CCSs were more likely to experience SI during active cancer treatment than in later years (14% vs. 8%).

Previous research has found that several risk factors are associated with suicidality outcomes, including preexisting mental illness, poor physical health, male sex, being single, older age, and cancer type—such as pancreatic and esophageal cancer compared with patients with prostate cancer; or survivors of central nervous system tumors, testicular cancer, leukemia, and bone or soft tissue sarcomas. Nodal Hodgkin lymphoma, brain cancer, and kidney cancer had lower suicide risk compared with survivors of thyroid cancer and patients with acute lymphocytic leukemia. However, the researchers noted, the current study was not able to draw conclusions about suicidality and cancer type because the studies included in their analysis were not stratified for that information. 

As far as other factors, the researchers observed the following for suicidality among CCSs:

• Age: "Older children likely have a greater awareness of their condition and the implications on other aspects of life, such as the disruption of schooling."
• Sex: "The expectations society has set for men, where showing emotions is frowned upon, create unhealthy habits of regulating emotions....male CCSs are at a higher risk of SI as the cancer diagnosis could pose a threat to one’s masculine identity as it entails a lack of control over one’s body, as shown in some studies."

Study limitations included the small number of studies available for certain analyses, heterogeneity across studies due to varied populations with diverse sociocultural backgrounds, and the potential underreporting of suicide-related behaviors due to social stigma.

"To our knowledge, this is the first systematic review and meta-analysis that investigated the prevalence and risk of suicide and SI among CCSs," the researchers wrote in JAMA Network Open. "The difference in prevalence of SI (9%) compared with suicide (0.30%) suggests that while some CCSs have suicidal thoughts, only a subset acted on them. This finding highlights the urgency for early interventions to mitigate any suicide."

Given the elevated SI risk, they concluded, enhanced psychosocial support for CCSs, such as future longitudinal studies to better capture the temporal dynamics of suicide risk throughout survivorship, stratification of CCSs by cancer type, and demographic factors to better understand risk variations and inform targeted support policies, are needed.

No conflicts of interest were disclosed in the study.