Number of tumor-infiltrating lymphocytes in breast cancer brain metastases compared to matched breast primaries.

Published

Conference Paper

2049 Background: Breast cancer brain metastasis (BCBM) is frequent in advanced disease, has limited therapies, and is associated with poor prognosis. Increased stromal tumor infiltrating lymphocytes (sTILs) are prognostic in triple-negative breast cancer (TNBC) and predictive of therapeutic response in early breast cancer (BC). However, little is known about sTILs in the metastatic setting. We compared %sTILs between the largest known cohort of matched primary tumors and BCBM and correlated the results with clinical endpoints. Methods: We retrospectively investigated 37 matched primary tumors and BCBM tissue from three institutions. In addition, we identified 29 primary tumors from patients later diagnosed with BCBM. H&E-stained sections were manually measured for %sTILs using standard criteria. Wilcoxon signed rank tests assessed for changes in %sTILs between primary and metastatic lesions. A Cox proportional hazards model was used to determine if %sTILs in the breast tissue predicts time from primary tumor biopsy to diagnosis of brain metastasis (TTDBM) while adjusting for clinicopathologic features. Results: Average age at time of BCBM diagnosis was 53.6 (SD 12.3). 52% (34/66) of primary tumors were hormone receptor (HR) positive. Of 60 patients with known HER2 status, 28% (17) were HER2 positive and 40% (24) TNBC. Median %sTILS was significantly different between all primary tumors (15, IQR 5-20) and brain metastases (10, IQR 5-10), p = 0.001. The TNBC subtype (n = 11) showed the largest decrease in %sTILs between primary tumors (20, IQR 10-20) and brain metastases (5, IQR 5-10), p = 0.022. Comparing primary tumors and brain metastases, there was a 5% decrease in %sTILs in HR-/HER2+ (n = 5, p = 0.13) and HR+/HER2- (n = 7, p = 0.13), and a 5% increase in %sTILs in the HR+/Her2+ subtype (n = 9, p = 0.69). Percent sTILs in the primary tumors was not a significant predictor of TTDBM, when adjusting for race, age, HR status, and HER2 status, p = 0.87. Conclusions: BCBM have a significantly decreased %sTILs compared to their primary tumors, most prominent in TNBC. These results suggest altered tumor immunogenicity in the metastatic setting which has broad implications for the development of immunotherapy.

Full Text

Duke Authors

Cited Authors

  • Narloch, J; Luedke, C; Broadwater, G; Priedigkeit, N; Hall, A; Hyslop, T; Sammons, SL; Huggins-Puhalla, SL; Leone, JP; Ramirez, J; Kirkpatrick, JP; Ewend, MG; Fecci, PE; Brufsky, A; Lee, AV; Anders, CK; Blackwell, KL

Published Date

  • May 20, 2017

Published In

Volume / Issue

  • 35 / 15_suppl

Start / End Page

  • 2049 - 2049

Published By

Electronic International Standard Serial Number (EISSN)

  • 1527-7755

International Standard Serial Number (ISSN)

  • 0732-183X

Digital Object Identifier (DOI)

  • 10.1200/jco.2017.35.15_suppl.2049