Influence of PD-L1 expression in immune cells on the response to radiation therapy in patients with oropharyngeal squamous cell carcinoma.

Abstract

BACKGROUND AND PURPOSE:

To investigate influences of proteins involved with tumor immunity on outcomes of radiotherapy for oropharyngeal squamous cell carcinoma (OPSCC).

MATERIAL AND METHODS:

We performed immunohistochemical staining to examine expressions of p16 and proteins involved with tumor immunity in 92 OPSCC patients treated with radiotherapy.

RESULTS:

Patients with abundant infiltrating CD8-positive cells had the significantly better overall survival (OS) rate than patients with fewer CD8-positive cells (p = 0.026). Patients with higher PD-L1 expression in tumor cells (TC 1-3) had a better outcome than those with low PD-L1 expression in tumor cells (TC 0) for both OS (p = 0.019) and progression-free survival (PFS) rate (p = 0.032). Patients with high PD-L1 expression in infiltrating immune cells (IC 3) showed significantly better OS (p = 0.009) and PFS (p = 0.011) than those with low PD-L1 expression (IC 0-2). Patients with p16-negative and IC 3 showed similar OS to patients with p16-positive and IC 0-2. P16-positive tumors had a significantly higher CD8-positive cell infiltration and PD-L1 expression in tumor cells than p16-negative tumors.

CONCLUSIONS:

In addition to tumor p16 expression, PD-L1 expression in TC and IC can be useful for predicting the response of OPSCC to radiotherapy.

• Authors: Yuki Fukushima, Masanori Someya, Kensei Nakata, Masakazu Hori, Mio Kitagawa, Tomokazu Hasegawa, Takaaki Tsuchiya, Toshio Gocho, Hikaru Ikeda, Yoshihiko Hirohashi, Toshihiko Torigoe, Shintaro Sugita, Tadashi Hasegawa, Tetsuo Himi, Koh-Ichi Sakata
• Journal: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology (Radiother Oncol) Vol. 129 Issue 2 Pg. 409-414 (11 2018) ISSN: 1879-0887 [Electronic] Ireland
• PMID: 30249348 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2018. Published by Elsevier B.V.

Chemical References

• B7-H1 Antigen
• Biomarkers, Tumor
• CD274 protein, human
• Neoplasm Proteins

Topics

• Adult
• Aged
• Aged, 80 and over
• B7-H1 Antigen (metabolism)
• Biomarkers, Tumor (metabolism)
• CD8-Positive T-Lymphocytes (immunology)
• Female
• Humans
• Kaplan-Meier Estimate
• Lymphocytes, Tumor-Infiltrating (immunology)
• Male
• Middle Aged
• Neoplasm Proteins (metabolism)
• Oropharyngeal Neoplasms (immunology, pathology, radiotherapy)
• Retrospective Studies
• Squamous Cell Carcinoma of Head and Neck (immunology, pathology, radiotherapy)