Commentary on early survival gains from adding radiotherapy to ımmunotherapy in bone-metastatic NSCLC.

Dear Editor,
I read with interest the study performed by Beyon et al. on adding radiotherapy (RT) to immunotherapy (IO) in stage IV non–small cell lung cancer (NSCLC) patients who developed bone metastasis, published in your journal recently (Beyon et al. 2025). The authors showed an early survival advantage within 100 days, which is biologically plausible and recently supported with mechanistic insights.
Radiotherapy has been increasingly regarded as an immunomodulatory agent acting to enhance antigen release, dendritic cell activation, and cGAS–STING pathway activation to augment the abscopal effects of immune checkpoint (Zhang et al. 2022; Janopaul-Naylor et al. 2021). This immunologic underpinning provides a rationale for the early risk reduction observed in this study and is consistent with emerging evidence of synergy between RT and IO in metastatic NSCLC (Xia et al. 2020; Foster et al. 2019; Theelen et al. 2021).
This focus on bone metastasis is clinically relevant given that the bone is a highly immunosuppressive metastatic niche. Multiple studies have indicated that bone metastases contain myeloid-derived suppressor cells, osteoclast-mediated cytokine signaling, hypoxia, and chronic T-cell dysfunction, which collectively act to dampen IO responses (Arellano et al. 2022; Chen et al. 2024; Hiraga and Yoneda 2018). In addition, preclinical studies indicate that RT may re-educate the bone metastatic microenvironment in a transitory fashion to increase its immunogenicity (Guo et al. 2023; Asano et al. 2022; Takada et al. 2022). These results are consistent with the survival benefit seen early by the authors.
In spite of these strengths, some limitations require explanation. The study does not report RT-specific details, including dose, fractionation, stereotactic vs. conventional technique, and treated sites. These variables are important because SBRT leads to greater systemic immune activation and higher abscopal response rates compared with conventional RT. Without this information, it is unclear what proportion of the observed effect comes from bone-targeted RT compared to RT for other metastatic sites.
The subgroup analyses, particularly within squamous histology, seem to be underpowered based on the CIs being wide. These are hypothesis-generating results. Moreover, the small median OS benefit of 7.1 months should be read in light of new evidence suggesting that long-term IO efficacy results from persistent immunoreprogramming rather than early local control (Liu et al. 2023).
Residual confounding by systemic inflammatory and nutritional markers (e.g., albumin), which have been observed to independently affect IO outcomes, may also explain, in part, the survival differences (Horstman et al. 2024; Veccia et al. 2024).
These biomarkers need to be considered in the context of real-world data.Overall, Beyon et al. offer real-world evidence supporting early RT and IO integration in NSCLC with bone metastasis. Prospective future trials integrating specific radiation parameters and translational immune biomarkers will be crucial to enable patient selection and the optimal utilization of combined RT IO strategies.
Sincerely,
Pınar Peker, MD