Differential effects of CD20+ B cells and PD-L1+ immune cells on pathologic complete response and outcome: comparison between inflammatory breast cancer and locally advanced breast cancer patients

Breast Cancer Res Treat. 2021 Dec;190(3):477-489. doi: 10.1007/s10549-021-06391-5. Epub 2021 Sep 20.

Abstract

Purpose: This study evaluated epidemiologic and immune factors associated with pathologic complete response (pCR), breast cancer-specific survival (BCSS) and disease-free survival (DFS) outcomes in inflammatory (IBC) and locally advanced breast cancer (LABC) patients.

Methods: Tumor-infiltrating lymphocytes (TILs) and CD20+ B-cell frequencies (CD20+), and PD-L1 expression on tumor (PD-L1+carcinoma cells) and immune (PD-L1+TILs) cells were analyzed by immunohistochemistry along with clinicopathologic factors as modifiers of pCR and outcomes in 221 IBC and 162 LABC patients. Analysis included Kaplan-Meier curves and Cox proportional hazard models.

Results: IBC and LABC display similar levels of TILs, CD20+, and combined CD20+ and PD-L1+TILs (CD20+PD-L1+TILs), while LABC contained more PD-L1+TILs and PD-L1+ carcinoma cells. Absence of lymphovascular involvement, high TILs, PD-L1+ carcinoma cells, and combined CD20+ and PD-L1+ carcinoma cells correlated with pCR in IBC and LABC patients. High PD-L1+TILs correlated with pCR only in LABC; less lymph node involvement at diagnosis, CD20+ and CD20+PD-L1+TILs correlated with pCR only in IBC (P < 0.04, all comparisons). Achievement of pCR in IBC and LABC patients correlated with BCSS and DFS (P < 0.02). In multivariate analyses, pCR remained an independent prognostic factor of improved DFS in IBC and LABC patients, but of BCSS in only LABC. CD20+PD-L1+TILs remained an independent prognostic factor of improved DFS and BCSS only in IBC.

Conclusion: CD20+PD-L1+TILs are an independent prognostic biomarker of improved outcomes in IBC, but not LABC. Selecting IBC patients by CD20 and PD-L1 status could stratify patients and potentially identify those in whom activating CD20 agents and anti-PD-1/PD-L1 therapy could be explored.

Keywords: CD20; Immuno-oncology; Inflammatory breast cancer; Locally advanced breast cancer; PD-L1; Patient outcomes; Tumor-infiltrating lymphocytes; pCR.

MeSH terms

  • Antigens, CD20
  • B-Lymphocytes
  • B7-H1 Antigen / genetics
  • Biomarkers, Tumor
  • Breast Neoplasms* / drug therapy
  • Female
  • Humans
  • Inflammatory Breast Neoplasms*
  • Lymphocytes, Tumor-Infiltrating
  • Prognosis

Substances

  • Antigens, CD20
  • B7-H1 Antigen
  • Biomarkers, Tumor
  • CD274 protein, human