Prevalence of diabetes mellitus in long-term cancer survivors treated with craniospinal irradiation

Background Childhood, adolescent and young adult cancer survivors (CAYA) are at an increased risk for metabolic disorders such as diabetes mellitus (DM). While this risk has been well-documented for leukemia survivors and those exposed to abdominal radiotherapy, the metabolic risk profile for brain tumor survivors remains largely unexplored. Methods This study assessed the prevalence of diabetes and dysglycemia in two CAYA survivor cohorts. The first included medulloblastoma and ependymoma survivors (HIT-MED), with data collected via self-reported online questionnaires. The second (CLI) was a retrospective analysis of an unselected cohort from our late effects clinic. In this cohort dysglycemia was defined using HbA1c measurements alone, without additional glucose-based diagnostic criteria. Results In the HIT-MED group, 37% (197/527) participated in an online-based questionnaire, revealing a DM prevalence of 3.05%. 122 were male and 75 female, mean age was 27.1 ± 4.5 years (range;19,41). In comparison to an age-matched general population, there was no significant difference (p=0.468). Among survivors in the CLI group who received craniospinal irradiation (mean age 38 years at assessment), 34.6% (9/26) exhibited dysglycemia, including 7.7% (2/26) with diabetes mellitus and 26.9% (7/26) with prediabetic glucose levels. This represented the second highest prevalence of impaired glucose regulation among all irradiation subgroups. Conclusion CAYA brain tumor survivors exposed to craniospinal radiotherapy have an elevated risk of dysglycemia compared to other survivor cohorts. These findings support the need for structured, risk-adapted long-term metabolic monitoring to enable early intervention and reduce long-term morbidity.