A retrospective study of characteristics and survival in patients with breast cancer brain metastases classified by subtype using NCI SEER registry.

Abstract

1031 Background: Breast cancer brain metastasis (BCBM) de novo is associated with the worst prognosis among all types of metastases in breast cancer (BC). Analysis of factors associated with BCBM stratified by subtype of BC could lead to earlier identification of metastasis. Methods: 1,268 patients with BCBM at the time of BC diagnosis and known clinical subtype (580 HR+/HER2-, 225 HR+/HER2+, 176 HR-/HER2+, and 287 HR-/HER2-) who were ≥ 20 years of age from 2010 to 2017 were identified using the NCI’s Surveillance, Epidemiology, and End Results (SEER) Program 18 registry. Baseline characteristics and survival were analyzed using Chi-Square and Kaplan-Meier methods. Results: Patients with HR-/HER2+ BC were the most likely to present with BCBM, compared to all BC patients (prevalence of 13.9% vs. 4.7%; p<0.001). Further analysis demonstrated that HER2+ patients had an odds ratio of presenting with BCBM of 2.52 (95% CI: 2.24-2.84) compared to HER2- patients. Interestingly, in patients ages 20-39 with HR-/HER2+ BC, higher rates of brain metastases are noted within the BCBM group compared to all HR-/HER2+ breast cancer cases (28% vs. 7.6%; p<0.001). The same trend is seen within the HR-/HER2+ African American population, with those in the BCBM group experiencing higher rates of brain metastases compared to all BC cases with the same subtype (14.3% vs. 5.9%; p<0.001). Upon exploring insurance demographics, uninsured patients with HR-/HER2+ BCBM had much higher rates of brain metastases compared to all HR-/HER2+ BC cases (14.8% vs 6.4%; p=0.001). When examining TNM status, significant associations were noted between brain metastases and increased tumor and nodal status. Patients with T4 or N3 status with HR-/HER2+ BCBM exhibited much higher rates of metastasis compared to all BC cases with the same subtype (p<0.001). Analysis of survival outcomes showed a median overall survival of 12 months for patients with HR-/HER2+ BCBM. The results displayed in the table below show that HR-/HER2- BCBM patients had the lowest 5-year percent survival, while HR+/HER2+ BCBM patients had the highest 5-year survival. Conclusions: This SEER database study provides insight into the demographics, clinical variables, and outcomes for BC clinical subtypes, specifically HR-/HER2+, from 2010 to 2017 in the United States. HR-/HER2+ breast cancer patients within the noted high-risk populations should be made aware of the increased rates of brain metastases compared to the general BC population, as earlier identification of brain metastases within the HR-/HER2+ cohort could improve patient survival.[Table: see text]

Novel Therapies for the Treatment of HER2-Positive Advanced Breast Cancer: A Canadian Perspective

“…According to the ASCO 2018 guidelines for the treatment of patients with HER2-positive metastatic breast cancer, clinicians With improvement to systemic therapies for patients with HER2-positive breast cancer resulting in longer survival, the incidence of brain metastases has increased, developing in up to half of the patients during the course of their disease [49][50][51][52]. Moreover, patients with HER2-positive breast cancer are close to three times as likely to be diagnosed with brain metastases [53]. However, the role of brain imaging in a patient with recurrent disease is controversial, and there is no consensus.…”

Current and future landscape of targeted therapy in HER2-positive advanced breast cancer: redrawing the lines

“…12,13 Improved systemic control has led to an increased prevalence of brain metastases, possibly due to variable penetrance of MoAbs across the blood–brain barrier. 14 Patients with hormone receptor negative, HER2-positive BC are nearly three times more likely to present with brain metastases, 15 and approximately half of patients with metastatic HER2-positive BC are expected to develop brain metastases over the course of their illness. 16–18…”

“…12,13 Improved systemic control has led to an increased prevalence of brain metastases, possibly due to variable penetrance of MoAbs across the blood-brain barrier. 14 Patients with hormone receptor negative, HER2-positive BC are nearly three times more likely to present with brain metastases, 15 and approximately half of patients with metastatic HER2-positive BC are expected to develop brain metastases over the course of their illness. [16][17][18] Currently, the recommended first-line treatment for most patients with advanced HER2-positive BC is trastuzumab plus pertuzumab and a taxane based on results from CLEOPATRA, [19][20][21] with the ADC trastuzumab emtansine (T-DM1) consisting of the humanized MoAb trastuzumab covalently linked to the cytotoxic agent DM1, a standard second-line option based on the EMILIA trial.…”