Abstract P1-21-04: The real word study on clinical features and prognostic factors of Chinese breast cancer patients with brain metastasis

Abstract Purpose: we used the real-world data of Chinese patients to describe clinicopathological characteristics of patients with breast cancer brain metastases (BCBM) and to investigate survival after diagnosis of brain metastases (BM). Methods: The clinicopathological characteristics of 700 patients with BCBM at the fifth Medical Center of Chinese PLA General Hospital between 2003 and 2021 were retrospectively reviewed. Information was collected from the electronic medical records, including patient demographics, tumor characteristics, and dates of diagnosis of original breast carcinoma and subsequent metastases. Sites and number of metastatic lesions were also recorded, along with data on treatments and outcomes. The prognostic and predictive effects of these clinicopathological variables in BCBM were analyzed. Results: The median age at diagnosis of primary breast cancer was 44 years (range, 22-80 years) and all patients were female. Among the 700 patients with BCBM, 30.0%, 49.7%, 18.9%, 1.4% had Luminal, HER2 positive, triple-negative and unknown subtypes, respectively. Based on available clinical information, the proportions of extracranial metastasis at diagnosis included bone (63.7%), lymph nodes (61.6%), lung (55.1%), liver (50.1%), the soft tissues of the thoracic wall (26.1%) and bone marrow (4.9%).The median time from the diagnosis of breast cancer to the development of BM was 52.0 months [95% confidence interval (CI), 44.3-59.7], 36.0 months (95%CI, 31.9-40.1), and 29.0 months (95%CI, 22.4-35.6) for patients with Luminal, HER2 positive and triple-negative, respectively (p<0.0001) (Figure 1). The median time from the first recurrence to the diagnosis of BM was 18 months for Luminal subtype (95% CI, 15.3-20.7), 14 months for HER2 positive subtype (95% CI, 12.0-16.0), and 12 months for triple-negative subtype (95% CI, 9.0-15.0), respectively (p<0.0001) (Fig 2). The median survival after the diagnosis of BCBM in Luminal, HER2 positive and triple-negative patients was 11 months (95% CI, 8.7-13.2), 13 months (95% CI, 11.4-14.6) and 7 months (95% CI, 5.7-8.3), respectively(p<0.05) (Fig 3). Patients presenting with a solitary brain metastasis had a longer median survival after the diagnosis of BM than patients who presented with multiple brain metastases (14.0 months versus 9 months, p<0.0001). The median survival time of patients with and without anti-HER2 treatment was 14 months (95% CI, 12.2-15.8) and 9 months (95% CI, 6.1-11.9), respectively (p=0.01) (Fig 4). Patients presenting with leptomeningeal metastasis had shorter time after the diagnosis of BM than patients without leptomeningeal metastasis, which were 5 months (95% CI, 1.8-8.2) and 11 months (95% CI, 9.8-12.2), respectively (p=0.002). Conclusion: Despite the improvement noted with more recent year of diagnosis and treatment, survival following a diagnosis of BCBM remains poor and still needs attention. It is necessary to further explore the comprehensive treatment mode of patients with different types and degrees of brain metastasis in order to provide reference for clinical treatment. Table 1.patient characteristics (n=700)Parametern (%)Mean age, y, at diagnosis (range)44(22-80)Stage at initial diagnosis of cancerI89(12.7)II342(48.9)III167(23.9)IV69(9.9)unknown33(4.7)Molecular subtypesLuminal A/B211(30.0)HER2-positive347(49.7)TNBC132(18.9)Unknown10(1.4)Site of first metastasisBrain128(18.3)Others572(81.7)Number of BM at time of BM diagnosis1189(27.0)248(6.9)≥3454(64.9)Unknown9(1.3)Visceral metastases at diagnosis of BMliver351(50.1)lung386(55.1)bone446(63.7)lymph nodes431(61.6)the soft tissues of the thoracic wall183(26.1)bone marrow34(4.9) Citation Format: Tao Wang, Huiqiang Zhang, Feng Li, Xia Wu, Jinmei Zhou, Shao hua Zhang, Li Bian, Ze fei Jiang. The real word study on clinical features and prognostic factors of Chinese breast cancer patients with brain metastasis [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-21-04.