Abscopal effect in metastatic breast cancer treated with stereotactic body radiotherapy in the absence of immunotherapy

Frontiers in Oncology

Oncology

Ah Ram Chang¹  Jae Sik Kim¹ 

[1] Department of Radiation Oncology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, Republic of Korea;

关键词: abscopal effect;    breast cancer;    metastasis;    neutrophil-to-lymphocyte ratio;    stereotactic body radiotherapy;   

DOI  :  10.3389/fonc.2023.1243053

 received in 2023-06-20, accepted in 2023-09-14,  发布年份 2023

来源: Frontiers

【 摘 要 】

PurposeIn this study, we aimed to assess the abscopal effect (AE) after CyberKnife stereotactic body radiotherapy (SBRT) in metastatic breast cancer patients without immunotherapy.MethodsWe reviewed breast cancer patients who received SBRT with a fraction size of ≥ 6 Gy for metastatic lesions between July 2008 and December 2021. We selected patients who had at least one measurable extracranial lesion in addition to SBRT target lesions and were not treated with immunotherapy. A total of 40 SBRT cases from 34 patients were included in the analysis. The AE was defined as occurring before the overall progression of the disease, regardless of the use of systemic treatment.ResultsThe median follow-up duration was 16.4 months. Among 40 SBRT cases, the AE was observed in 10 (25.0%) with a median interval of 2.1 months. Of these lesions, 70.0% did not progress for one year. In multivariate logistic regression analysis, no change in systemic treatment after SBRT was significantly associated with an increase in the AE (odds ratio [OR] = 1.428, 95% confidence interval [CI] = 1.108 – 1.841, p = 0.009). A post-SBRT neutrophil-to-lymphocyte ratio (NLR) of < 2 marginally increased the AE (OR = 1.275, 95% CI = 0.998 – 1.629, p = 0.060). However, a high SBRT dose and large planning target volume did not (p = 0.858 and 0.152, respectively) in univariate analysis.ConclusionsOne out of four patients experienced the AE after SBRT in the absence of immunotherapy. The AE could occur more frequently when systemic treatment remains unchanged, and patients have a low NLR after SBRT.

【 授权许可】

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Copyright © 2023 Kim and Chang