Impact of adjuvant chemotherapy and radiotherapy on tumour-infiltrating lymphocytes and PD-L1 expression in metastatic breast cancer.

Abstract

BACKGROUND:

Chemotherapy and radiotherapy were postulated to induce an inflamed tumour microenvironment. We aimed to evaluate the effects of adjuvant chemotherapy/radiotherapy on tumour-infiltrating lymphocytes (TILs) and programmed death-ligand 1 (PD-L1) expression in metastatic breast cancer.

METHODS:

We identified paired primary and metastatic tumours in 85 patients with breast cancer. Stromal TILs were assessed according to international guidelines. PD-L1 expression was evaluated using the VENTANA SP142 assay.

RESULTS:

TILs were significantly lower in metastatic tumours than in primary tumours (12.2 vs. 8.3%, p = 0.049). PD-L1 positivity was similar between primary and metastatic tumours (21.2 vs. 14.1%, p = 0.23). TILs were significantly lower in patients who received adjuvant chemotherapy than in those who did not (-9.07 vs. 1.19%, p = 0.01). However, radiotherapy had no significant effect on TILs (p = 0.44). Decreased TILs predicted worse post-recurrence survival (hazard ratio, 2.94; 95% confidence interval [CI]: 1.41-6.13, p = 0.003), while increased TILs was associated with a better prognosis (HR, 0.12; 95% CI: 0.02-0.08, p = 0.04).

CONCLUSIONS:

TILs decreased in metastatic tumours, particularly in patients who relapsed after adjuvant chemotherapy. Changes in TILs from primary to metastatic sites could be a prognostic factor after recurrence.

• Authors: Shu Yazaki, Roberto Salgado, Tatsunori Shimoi, Masayuki Yoshida, Sho Shiino, Tomoya Kaneda, Yuki Kojima, Hitomi Sumiyoshi-Okuma, Tadaaki Nishikawa, Kazuki Sudo, Emi Noguchi, Takeshi Murata, Shin Takayama, Akihiko Suto, Yuichiro Ohe, Kan Yonemori
• Journal: British journal of cancer (Br J Cancer) Vol. 128 Issue 4 Pg. 568-575 (02 2023) ISSN: 1532-1827 [Electronic] England
• PMID: 36522476 (Publication Type: Journal Article)
• Copyright: © 2022. The Author(s).

Chemical References

• CD274 protein, human
• B7-H1 Antigen

Topics

• Humans
• Female
• Breast Neoplasms (pathology)
• B7-H1 Antigen (metabolism)
• Lymphocytes, Tumor-Infiltrating (pathology)
• Prognosis
• Chemotherapy, Adjuvant
• Tumor Microenvironment