The breast graded prognostic assessment is associated with the survival outcomes in breast cancer patients receiving whole brain re-irradiation

Abstract

Whole brain (WB) re-irradiation for breast cancer patients with progressive brain metastasis after first-course WB radiotherapy (WBRT) is controversial. In this study, we sought to investigate the association between the molecular sub-classifications and breast-specific Graded Prognostic Assessment (GPA, which includes the Karnofsky performance status, molecular subtypes, and age as its indices) and the outcomes of breast cancer patients who received WB re-irradiation. Twenty-three breast cancer patients who received WB re-irradiation for relapsed and progressive intracranial lesions after first-course WBRT between 2004 and 2016 were retrospectively reviewed. Patients were divided according to the 4 molecular subtypes of luminal A/B (hormone receptor [HR]+/human epidermal growth factor receptor 2 [HER2]-), luminal HER2 (HR+/HER2+), HER2 (HR-/HER2+), and triple negative (HR-/HER2-). The clinical and radiological responses and survival rates after WB re-irradiation were analyzed. At 1 month after WB re-irradiation, 13 of 23 patients (56.5%) exhibited disappearance or alleviation of neurological symptoms. The median survival time after WB re-irradiation was 2.93 months (95% confidence interval [CI], 1.79-4.08). After WB re-irradiation, patients with HER2-negative tumors had poorer median survival times than those with HER2-positive tumors (2.23 vs. 3.0 months, respectively; p = 0.022). Furthermore, patients with high breast GPA scores (2.5-4.0, n = 11) had longer median survivals than those with low-scores (0-2.0, n = 12) after WB re-irradiation (4.37 vs. 1.57 months, respectively; p < 0.005). WB re-irradiation may be a feasible treatment option for certain breast cancer patients who develop brain metastatic lesions after first-course WBRT when these lesions are ineligible for radiosurgery or surgery.