Research Article: Efficacy and safety of stereotactic radiotherapy in patients with HER2-positive breast cancer brain metastases following intracranial oligoprogression
Abstract:
Tyrosine kinase inhibitors (TKIs) demonstrate clear therapeutic effects in patients with HER2?positive breast cancer complicated by brain metastases. However, the efficacy and safety of salvage stereotactic radiotherapy (SRT) for intracranial oligoprogression after TKI therapy remain unclear. This single-center retrospective cohort study aimed to evaluate the clinical value of SRT in this specific population, enrolling 40 HER2-positive breast cancer patients with brain metastases who received SRT for intracranial oligoprogression after TKI therapy at the Department of Radiotherapy, Fourth Hospital of Hebei Medical University between January 2020 and January 2025. Patients were stratified into the MRI-stable disease (SD) group and MRI-progressive disease (PD) group according to intracranial oligoprogression features. The main outcome measures included post?radiotherapy intracranial progression?free survival (poRT?iPFS), time to next systemic treatment (NEST), overall survival (OS), and treatment safety. The median follow-up duration was 10.7 months (interquartile range [IQR] 7.0–20.8 months), with a median poRT-iPFS of 6.4 months (95% confidence interval [CI] 6.3–8.3 months), median NEST of 5.2 months (95% CI 4.7–6.5 months), and median OS of 9.5 months (95% CI 8.6–10.6 months). Stratified analysis revealed a significantly longer median poRT-iPFS in the MRI-SD group than in the MRI-PD group (7.9 months, 95% CI 7.5–8.3 vs. 5.5 months, 95% CI 4.6–6.4; P < 0.001). The main grade ? 3 treatment-related adverse events (TEAEs) were diarrhoea (20%), anaemia (20%), leucopenia (18%), nausea (15%), and thrombocytopenia (13%); Only 2 patients (5%) developed grade 1 radiation necrosis, and no interstitial pneumonia was reported. In conclusion, SRT provides considerable survival benefits and a manageable safety profile for HER2-positive breast cancer patients with brain metastases who develop intracranial oligoprogression after TKI therapy. MRI-stable intracranial lesions accompanied by increased peritumoural oedema may serve as a valuable indicator for initiating proactive radiotherapy intervention.
Introduction:
Breast cancer ranks second only to lung cancer as the most common malignancy associated with brain metastasis ( 1 ). Statistics indicate that roughly one-third of breast cancer patients develop brain metastasis during the disease course, and this proportion reaches nearly half among those with the human epidermal growth factor receptor 2 (HER2)-positive subtype ( 2 ). Local radiotherapy and surgical resection are well-established standard treatments for breast cancer-related brain metastases ( 3 ). Nevertheless,…
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