Sci Rep. 2025 Jul 9;15(1):24600. doi: 10.1038/s41598-025-08974-4.ABSTRACTBACKGROUND: The use of immune checkpoint inhibitors (ICIs) is increasingly important in melanoma management. While ICIs are associated with immune-related adverse events (irAEs), little is known about skeleton irAEs and they are felt to be poorly described.METHODS: We conducted a real-life, retrospective cohort study to monitor bone mineral density (BMD) evolution over 2 years using routine Computed Tomography (CT) in melanoma patients treated with ICIs and to identify associated factors. This single-center study included 165 patients (mean age: 65 years; 44.2% women) treated with ICIs between 2014 and 2023. BMD was measured at baseline (T0), 1 year (T1), and 2 years (T2) on L1 vertebrae. Vertebral fractures were assessed on sagittal slices. Paired t-tests compared BMD values at the different time points, and we analyzed risk factors for BMD changes with regression models.RESULTS: BMD significantly decreased over 2 years (mean difference: 14.02 Hounsfield Units (HU), 95% CI 10.31-17.74, p < 0.001), with bone loss rates of 5.15% and 11.91% at 1 and 2 years, respectively. Male sex (β 8.25, p = 0.002) and younger age (β -0.34, p = 0.001) were linked to greater BMD decline at 1 year. Disease progression or partial response correlated with greater reductions at 2 years. Multivariable analysis confirmed male sex as an independent risk factor for BMD loss.CONCLUSION: ICIs are associated with significant BMD loss, particularly in men. These findings emphasize the importance of osteoporosis prevention and routine BMD monitoring during ICI therapy.PMID:40634374 | DOI:10.1038/s41598-025-08974-4