Research presented at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting indicated that the following prognostic factors impact overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer and brain metastases:
- Age at diagnosis
- Number of brain metastases
- Amount of chemotherapy received with trastuzumab
- Receipt of 3 different HER2-targeted therapies
Brain metastasis is an indicator of poor survival in patients with breast cancer. Researchers retrospectively assessed 83 patients (median age, 49 years; range, 25-76 years) with HER2-positive metastatic breast cancer and brain metastases between 2008 and 2018. More than one-third of the patients (n=32; 38.6%) had de novo disease at diagnosis. Most patients (88.4%) had invasive ductal carcinoma. Some patients had estrogen receptor-positive (42.2%) or progesterone receptor-positive (28.9%) tumors.
Median number of extra-cranial metastasis was 2 (range, 0-4), most commonly occurring in the bone (63.9%), liver (41%), and lung (34.9%). A total of 28 patients (41.8%) had solitary brain metastasis. At diagnosis, median brain metastasis size was 16 mm (range, 5-63 mm).
All patients had received trastuzumab-based chemotherapy, 29 (34.9%) received trastuzumab emtansine, and 73 (88%) received combination lapatinib and capecitabine. A total of 17 patients (20.5%) had undergone craniotomy, and 82 (98.8%) received brain radiotherapy. Some patients also received hormonotherapy (41%) and bisphosphonates (56.6%).
After a median follow-up of 36 months (range, 5.9-177.7 months) from beginning of metastasis, median OS was 34.9 months (95% CI, 24.6-45.2). The following factors were significant predictors of OS: age at diagnosis (P=.005), presence of 5 or more brain metastasis (P=.016), amount of chemotherapy used with trastuzumab (P=.017), and receipt of 3 different HER2-targeted therapies (P=.032). Size of brain metastasis (P=.091), lung metastasis (P=.428), liver metastasis (P=.338), bone metastasis (P=.132), and tumor hormone positivity (P=.238) did not appear to impact survival.
Dogan I, Yirgin IK, Ozkurt S, et al. Outcomes and prognostic factors in patients with HER2-positive metastatic breast cancer with brain metastasis. Abstract #e14002. Presented at the 2022 American Society of Clinical Oncology Annual Meeting; June 3-7, 2022; Chicago, IL.