Prognostic impact of p16 and PD-L1 expression in patients with oropharyngeal squamous cell carcinoma receiving a definitive treatment.

Limited information is available regarding the precise differences in the tumour immune microenvironment (TIM) of patients with human papilloma virus (HPV)-associated and non-HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). Here, we retrospectively reviewed 137 patients with OPSCC treated with a definitive treatment to identify molecular relationships in the TIM. We used immunohistochemical analysis to assess p16 status, programmed death ligand 1 (PD-L1) level, and/or CD8+ tumour-infiltrating lymphocyte (TIL) density, followed by prognostic evaluation of these immune-related parameters. Multivariate analyses demonstrated that PD-L1 level on immune cells but not on tumour cells or CD8+ TIL density was a significant predictive factor of disease-free survival (DFS) and overall survival (OS). Additionally, subgroup analyses demonstrated that patients positive for p16 and PD-L1 expression on immune cells had favourable DFS and OS, whereas patients negative for p16 and PD-L1 expression on immune cells showed worse DFS and OS. We demonstrated that PD-L1 expression on immune cells but not tumour cells might represent a useful prognostic biomarker in patients with OPSCC receiving a definitive treatment. We propose that a co-assessment of p16 and PD-L1 expression on immune cells would have greater prognostic potential compared with evaluation of each factor alone in patients with OPSCC.

Sato F ，Ono T ，Kawahara A ，Kawaguchi T ，Tanaka H ，Shimamatsu K ，Kakuma T ，Akiba J ，Umeno H ，Yano H ... -  《-》

PD-L1 Expression and a High Tumor Infiltrate of CD8+ Lymphocytes Predict Outcome in Patients with Oropharyngeal Squamous Cells Carcinoma.

Wuerdemann N ，Gültekin SE ，Pütz K ，Wittekindt C ，Huebbers CU ，Sharma SJ ，Eckel H ，Schubotz AB ，Gattenlöhner S ，Büttner R ，Speel EJ ，Klussmann JP ，Wagner S ，Quaas A ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

The tumor immune microenvironment and its implications for clinical outcome in patients with oropharyngeal squamous cell carcinoma.

We examined PD-L1 expression on tumor cells (TCs) and immune cells (ICs) and density of CD3+ and CD8+ tumor-infiltrating lymphocytes (TILs) in patients with oropharyngeal squamous cell carcinoma (OPSCC) and investigated their significance on clinicopathological characteristics and clinical outcomes. In a cohort of 65 patients treated by definitive intensity-modulated radiotherapy (IMRT) with curative intent, immunohistochemical analysis of PD-L1 expression on TCs and ICs, and TIL subtyping was performed on primary biopsy tumor tissues, followed by prognostic evaluation of these immune response-related parameters including classification into four tumor immune microenvironment (TIM) types. To evaluate HPV status, p16 immunohistochemistry was performed. Densities of CD3+ and CD8+ TILs and PD-L1 expressions on TCs and ICs were significantly higher in p16+/HPV-mediated OPSCC. Patients with high densities of stromal CD8+ TILs displayed significantly better overall survival (OS) and progression-free survival (PFS). PD-L1 expression neither on tumor cells nor on immune cells affected survival outcomes. Distribution of TIM types based on the combination of PD-L1 expression on TCs and densities of CD8+ TILs is significantly different in p16+ compared with p16- OPSCC. In type III TIM (TC-PD-L1+/low CD8+ TIL density), significantly better OS was shown in p16+ group compared with p16- OPSCC. The prognostic and predictive role of tumor immune microenvironment was confirmed for patients with OPSCC. Combining HPV status with the evaluation of densities of CD8+ TILs and PD-L1 expression including TIM classification might be of high clinical interest and warrants further prospective evaluation.

Gurin D ，Slavik M ，Hermanova M ，Selingerova I ，Kazda T ，Hendrych M ，Shatokhina T ，Vesela M ... -  《-》

Concordance of tumor infiltrating lymphocytes, PD-L1 and p16 expression in small biopsies, resection and lymph node metastases of oropharyngeal squamous cell carcinoma.

The incidence of oropharyngeal squamous cell carcinoma (OPSCC), especially human papillomavirus (HPV)-associated, is increasing worldwide. Immunotherapy become available for patients with carcinomas in the head and neck region, however without ideal biomarker. Markers like PD-L1 vary in the clone of the antibody used, and the method of evaluation. Adequate and reliable immune cells characterization and evaluation is still not found. Furthermore, studies analyzing representativeness of different tissue samples are scarce. We analyzed small biopsy, lymph node (LN) metastasis and resected OPSCC, in regards of tumor infiltrating lymphocyte (TIL) density, PD-L1 and p16 expression. Patients with OPSCC diagnosed from 2000 to 2016, with small biopsy, resection specimen and LN metastasis samples were selected. We analyzed TILs on hematoxylin-eosin stain, and PD-L1 and p16 expression in tumor cells. Concordance between different tumor locations was evaluated. 93 patients, with 65 small biopsies, 72 resection specimens, and 70 LN metastases were included. TILs, p16 and PD-L1 demonstrated very high concordance. Additionally, PD-L1 expression in the small biopsies was more representative of the PD-L1 expression in the resection specimens, than the LN samples. TILs density can be reliably assessed using hematoxylin-eosin stain with high concordance between the small biopsy, resection specimen and LN metastasis. Evaluation of concordance of p16 expression is very high, nevertheless some cases might be misdiagnosed on a small biopsy or lymph node metastasis. Evaluation of PD-L1 expression is very reliable on the biopsy specimen. Different PD-L1 clones and methods of evaluation still remain to be addressed.

Brcic I ，Gallob M ，Schwantzer G ，Zrnc T ，Weiland T ，Thurnher D ，Wolf A ，Brcic L ... -  《-》

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

To investigate influences of proteins involved with tumor immunity on outcomes of radiotherapy for oropharyngeal squamous cell carcinoma (OPSCC). We performed immunohistochemical staining to examine expressions of p16 and proteins involved with tumor immunity in 92 OPSCC patients treated with radiotherapy. 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. In addition to tumor p16 expression, PD-L1 expression in TC and IC can be useful for predicting the response of OPSCC to radiotherapy.

Fukushima Y ，Someya M ，Nakata K ，Hori M ，Kitagawa M ，Hasegawa T ，Tsuchiya T ，Gocho T ，Ikeda H ，Hirohashi Y ，Torigoe T ，Sugita S ，Hasegawa T ，Himi T ，Sakata KI ... -  《-》