2022 ASCO Annual Meeting , Illinois, United States Of America, 3 - 07 June 2022, pp.14002
Background: Breast cancer is the most common malignancy in females. Brain metastasis is a poor prognostic factor in breast cancer. Brain metastasis can develop in about half of the HER2- positive metastatic breast cancer patients. The study was aimed to determine outcomes and prognostic factors in HER2 positive metastatic breast cancer patients who had brain metastasis. Methods: We evaluated the HER2-positive metastatic breast cancer patients with brain metastasis between 2008 and 2018. Data of the patients were recorded retrospectively. Kaplan Meier and Cox regression analysis were used for survival analysis and prognostic factors. Results: Eighty-three patients were included in the study. The median age was 49 (range, 25-76). Thirty-two (38.6%) patients had de-novo metastatic disease at diagnosis. The most common histopathological type was invasive ductal carcinoma (88.4%). The estrogen receptor and progesterone receptor positivity ratios were 42.2% and 28.9%, respectively. At the beginning of brain metastasis, the median number of extra-cranial metastasis was 2 (range, 0-4). The most common extra-cranial metastasis sites were bone (63.9%), liver (41%), and lung (34.9%), respectively. Twenty-eight patients (41.8%) had solitary brain metastasis. The median size of brain metastasis was 16 mm (range, 5-63) at diagnosis. All patients had treated with trastuzumab-based chemotherapy, 29 patients (34.9%) TDM-1, and 73 patients (88%) lapatinib+capesitabine combination. Seventeen patients (20.5%) had undergone craniotomy, and 82 patients (98.8%) received brain radiotherapy. The patients also received hormonotherapy (41%) and bisphosphonates (56.6%). At a median follow-up of 36 months (range 5.9-177.7) from beginning metastasis, the median overall survival was 34.9 months (95% CI, range 24.6-45.2). In multivariate analysis, age at diagnosis (p = 0.005), presence of five and over brain metastasis (p = 0.016), the number of chemotherapy used with trastuzumab (p = 0.017), and receiving three different HER2-targetted therapy (p = 0.032) were statistically significant for overall survival. However, size of brain metastasis (p = 0.091), lung metastasis (p = 0.428), liver metastasis (p = 0.338), bone metastasis (p = 0.132), and hormone positivity of tumor (p = 0.238) were not. Conclusions: Real-life outcomes of HER2-positive breast cancer patients with brain metastases were presented in this study. We showed that age at diagnosis, number of brain metastasis, number of chemotherapy received with trastuzumab, and had received three different HER2 targetted therapy was prognostic factors for overall survival.