Fernandes I, Scorsato A, Kaliks R, Corpa M, Damasceno E, Schvartsman G. Tumor-Infiltrating Lymphocytes in HER2-Low Breast Cancer.
Clin Breast Cancer 2023;
23:e470-e479. [PMID:
37562994 DOI:
10.1016/j.clbc.2023.07.007]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 05/07/2023] [Accepted: 07/29/2023] [Indexed: 08/12/2023]
Abstract
INTRODUCTION
Tumor-infiltrating lymphocytes (TIL) is a predictive and prognostic biomarker for breast cancer (BC) HER2-positive and triple negative, but its presence in HER2-low tumors is unknown. We aimed to determine TIL levels in HER2-low tumors and its correlation with other clinicopathologic features.
MATERIALS AND METHODS
We retrospectively analyzed all the pathology reports of breast surgeries of a tertiary hospital in Sao Paulo, Brazil, from January 2021 to March 2022. Inclusion criteria were stage I to III invasive BC, and exclusion criteria were nonmalignancies and neoadjuvant therapy. We assumed HER2 categories according to ASCO/CAP guidelines. TILs were defined as absent (0), low (1%-10%), intermediate (11%40%) and high (≥ 41%). Ki-67 levels were categorized as low (up to 19%) and high (≥ 20%).
RESULTS
From 272 patients, 198 met the inclusion criteria. Histological grade 3 was found in 10, 19 and 47% of HER2-0, low, and positive tumors (P < .001). HER2-positive tumors had 82.6% of high Ki-67 levels, while HER2-negative and HER2-low showed 25.8% and 31.4% (P = .005). TILs in HER2-0, low, and positive tumors were, respectively, absent in 16.1%, 17.6%, and 8.7%; low in 70.2%, 52.9% and 34.8%; intermediate in 11.3%, 25.5% and 47.8%; and high in 2.4%, 3.9% and 8.7%. There was a statistically significant difference in TILs between HER2-negative versus HER2-positive groups (P < .001), but not between HER2-negative versus HER2-low, or HER2-low versus HER2-positive.
CONCLUSION
TILs in HER2-low are marginally higher than HER2-negative, but significantly lower than HER2-positive levels. HER2-low tumors do not seem to significantly differ biologically from HER2-negative tumors.
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