RT Journal Article
SR Electronic
T1 Molecular Characteristics of Lymphocyte-predominant Triple-negative Breast Cancer
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 2133
OP 2140
DO 10.21873/anticanres.14985
VO 41
IS 4
A1 RITSUKO SASAKI
A1 YOSHIYA HORIMOTO
A1 YUKA YANAI
A1 AIKO KURISAKI-ARAKAWA
A1 ATSUSHI ARAKAWA
A1 KATSUYA NAKAI
A1 MITSUE SAITO
A1 TSUYOSHI SAITO
YR 2021
UL http://ar.iiarjournals.org/content/41/4/2133.abstract
AB Background/Aim: Tumor-infiltrating lymphocytes (TILs) are considered a prognostic marker for triple-negative breast cancer (TNBC). Immune checkpoint inhibitor (ICI)-based treatments are more effective for tumors with PD-L1-positive TILs, suggesting crucial roles of TILs in the local tumor immunity. However, factors attracting TILs are still largely unknown. Focusing on tumor antigenicity, we examined TNBC samples to identify the characteristics of TIL-high tumors. Patients and Methods: Nine treatment-naïve TNBCs (TIL-high: five, TIL-low: four) were subjected to next-generation sequencing (NGS). Loss of heterozygosity (LOH) of PTEN was also analyzed. Results: A variety of copy number variations were observed, and no genes differed significantly between TIL-high and -low groups. However, PTEN loss was more frequently observed in the TIL-high group: 60% compared to 25% in TIL-low tumors. NGS correlated well with LOH analysis in identifying PTEN loss. All three tumors with PTEN loss in the TIL-high group showed high PD-L1. All nine samples were microsatellite-stable. Conclusion: Frequent PTEN loss and high expression of PD-L1 in TIL-high TNBC suggest that PTEN mutation may be a biomarker for ICIs.