Importance of choice of materials and methods in PD-L1 and TIL assessment in oropharyngeal squamous cell carcinoma.

AIMS: A great deal of research is being conducted into PD-L1 immunohistochemistry (IHC) and tumour-infiltrating lymphocytes (TILs) as predictive or prognostic biomarkers for immunotherapy, although several practical issues exist concerning their assessment. The aim of this research was therefore to assess the importance of choice of materials and methods in PD-L1 and TILs scoring in oropharyngeal squamous cell carcinoma (OSCC). METHODS AND RESULTS: IHC for PD-L1 (SP142 and 22C3 clone) and TILs subtyping was performed on formalin-fixed paraffin-embedded tissue slides (biopsy, resection and/or lymph nodes specimens) of 99 patients with OSCC. A comparative analysis of PD-L1 and TILs scoring was made between different types of tissue specimens, between different PD-L1 clones, between TILs and different subsets of TILs and between the quantitative and semiquantitative assessments. PD-L1 scoring resulted in fair to moderate agreement for 22C3 and SP142 between various tissue specimens, with higher agreement at higher cut-off values, and in moderate agreement for 22C3 versus SP142. Evaluation by four independent observers proved substantial inter-rater agreement for both clones with high consistency in their ratings. Moderate agreement was observed for TILs and TILs subsets for the comparison between biopsy and resection. Lastly, strong correlations were found between quantitative and semiquantitative assessment for all PD-L1 and TILs scores. CONCLUSIONS: Our results highlight the challenges associated with the evaluation of PD-L1 and TILs in OSCC. Further research is warranted to evaluate the use of these biomarkers in order to allow implementation of PD-L1 and TILs infiltrate as biomarkers in daily clinical practice.

CD70 and PD-L1 in anaplastic thyroid cancer - promising targets for immunotherapy.

AIMS: During recent years, immune checkpoint inhibition has proved to be effective in several solid malignancies. The aim of this study was to identify novel targets for immunotherapy in anaplastic thyroid cancer by analysis of the expression of tumour antigens for which therapeutic agents are available. METHOD AND RESULTS: By immunohistochemistry we observed tumoral expression of CD70 in 49% of cases. Expression of its receptor, CD27, was present mainly in lymphocytes surrounding and infiltrating the tumour and observed only rarely in tumour cells. CD70 expression was associated with the presence of a precursor papillary thyroid carcinoma and the presence of BRAF V600E mutations in the anaplastic thyroid cancer lesion. Furthermore, the expression of CD70 seems stable during progression of the disease. Tumoral expression of programmed cell death ligand 1 (PD-L1) was found in 28.6% of the anaplastic thyroid cancer cases. Programmed cell death 1 (PD-1), the receptor of PD-L1, was not expressed on the tumour cells. No association between CD70 expression and PD-L1 expression could be demonstrated. CONCLUSION: These data suggest that targeted immunotherapy for CD70/CD27 and PD-L1/PD-1 might be promising in anaplastic thyroid cancer. However, as a low amount of tumour-infiltrating lymphocytes was observed in most lesions, combined therapy with agents enhancing the invasion of lymphocytes in the tumour region needs to be considered.

CD70 Expression and Its Correlation with Clinicopathological Variables in Squamous Cell Carcinoma of the Head and Neck.

OBJECTIVE: Over the last decade, efforts have been made to get a better understanding of the tumor microenvironment and the role of the immune system in it. New insights into the CD27/CD70 signaling pathway point towards a role in tumor immunology, making CD70 an attractive target for immunotherapy. Here, we evaluate CD70 expression in squamous cell carcinoma of the head and neck (SCCHN). METHODS: CD70 immunohistochemistry was retrospectively performed on 95 tumor samples. Tumoral CD70 expression was scored and correlated with clinicopathological variables and overall survival (OS). RESULTS: CD70 expression in tumor cells was observed in 66 samples (69%) and was strongly associated with tumor differentiation grade (p < 0.001). CD70 expression was also observed in tumor-associated fibroblasts and endothelial cells. Additionally, the density of tumor-infiltrating lymphocytes correlated with OS (p = 0.042). CONCLUSION: This study describes the tumoral expression of CD70 in SCCHN. Results highlight the role of CD70 in tumor biology and identify CD70 as a novel therapeutic target. Further research is warranted.

First Evidence of Activity of Enfortumab Vedotin on Brain Metastases in Urothelial Cancer Patients.

Enfortumab vedotin (EV), an antibody-drug conjugate directed against Nectin-4, significantly prolonged survival compared to standard chemotherapy in patients with locally advanced or metastatic urothelial carcinoma who previously received platinum-based chemotherapy and a PD-1 or PD-L1 inhibitor. The overall response rate in the phase 3 EV301 trial leading to approval was 40.6%. However, no data have been published yet regarding the effect of EV on brain metastases. Here, we present three patients from different centers with brain metastases receiving EV. A 58-year-old white male patient, who had been heavily pretreated for urothelial carcinoma with visceral metastases and a solitary clinically active brain metastasis, started on EV 1.25 mg/kg on days 1, 8, and 15 of a 28-day cycle. After three cycles, the first evaluation showed a partial remission by RECIST v1.1, with a near complete response on the brain metastasis and disappearance of neurological symptoms. The patient is currently still receiving EV. A second, 74-year-old male patient started on the same regimen, after previous progression on platinum-based chemotherapy and avelumab in maintenance. The patient achieved a complete response and received therapy for five months. Nevertheless, therapy was discontinued at the patient's request. Shortly after, he developed new leptomeningeal metastases. Upon rechallenge with EV, there was a significant reduction in the diffuse meningeal infiltration. A third, 50-year-old white male patient also received EV after previous progression on cisplatin-gemcitabine and atezolizumab maintenance, followed by palliative whole-brain radiotherapy and two cycles of vinflunine. After three cycles of EV, there was a significant reduction in the brain metastases. The patient is currently still receiving EV. These are the first reports on the efficacy of EV in patients with urothelial carcinoma and active brain metastases.

Verrucous hyperplasia and verrucous carcinoma in head and neck: use and benefit of methotrexate.

Background and aim: Verrucous hyperplasia (VH) and verrucous carcinoma (VC) of the head and neck are two (pre)malignant entities that are slowly progressive with low tendency to metastasize. However, they can reduce the patient's Quality of Life (QoL) and may even transform into squamous cell carcinoma (SCC). As they are typically approached by surgical resection, some patients do not qualify for surgery. Methotrexate may be a systemic alternative but the response is mostly not durable. This case report tries to illustrate the potential role of methotrexate in VH/VC of the head and neck.Method: We describe four cases of patients with VH or VC of the head and neck who received methotrexate (40-60 mg/m2) in a weekly or two-weekly interval.Results: Two patients received methotrexate in a neoadjuvant setting. The first patient achieved a macroscopical complete response after 16 cycles and remained in remission after surgery. The second patient suffered from residual disease after 26 cycles and refused radical surgery.Two other patients refused surgery at the time of diagnosis and were proposed methotrexate as a salvage treatment. The first patient had an ongoing response on methotrexate after >60 cycles. The second patient achieved macroscopical complete remission after 28 cycles of methotrexate but suffered relapse by developing an oropharyngeal SCC in the same region.Conclusion: When surgery is not desirable in VH and/or VC, patients can be treated with methotrexate which has a reasonable effect and seems to be well tolerated. Nevertheless, surgery should be the preferred strategy to achieve complete remission.

Tumour infiltrating lymphocytes in oropharyngeal carcinoma: prognostic value and evaluation of a standardised method.

Tumour infiltrating lymphocytes (TILs) have been described as a biomarker for the host immune response against the tumour with prognostic properties. The International Immuno-Oncology Biomarkers Working Group (IBWG) proposed a standardised method for quantifying TILs in solid tumours to improve consistent and reproducible scoring. In this study, the methodology was tested in a retrospective population of oropharyngeal squamous cell carcinoma (OPSCC). TIL quantification was performed on 92 OPSCC samples (2004-2013) by four independent observers as described by the IBWG. Interobserver variability was assessed and results were correlated with clinicopathological variables and survival. TIL evaluation turned out to be challenging in OPSCC due to heterogeneity of TILs distribution, presence of pre-existing lymphoid tissue, surface ulceration or erosion and insufficient amount of intertumoural stroma in biopsies. Nonetheless, interobserver variability proved to be good to excellent. High stromal TILs (TILstr) and intratumoural TILs (TILtum) were both correlated to favourable overall survival and multivariate analysis showed TILstr to be the sole independent prognostic factor in OPSCC. The IBWG-proposed TIL quantification method is feasible and reproducible in OPSCC and provides valuable prognostic information regarding clinicopathological characteristics and overall survival. The use of this standardised methodology may facilitate implementation of TILs scoring as a prognostic biomarker in OPSCC.

An open-label, nonrandomized, phase Ib feasibility study of cusatuzumab in patients with nasopharyngeal carcinoma.

CD70 is expressed in up to 80% of nasopharyngeal carcinoma (NPC) cases. Cusatuzumab is a humanized anti-CD70 monoclonal antibody, with dual action mechanisms: induction of cytotoxicity against CD70+ tumor cells and reduction in CD70-CD27 signaling mediated immune evasion. The aim of this study was to assess the safety, pharmacokinetic profile, immunogenicity, pharmacodynamic profile, and preliminary activity of cusatuzumab in advanced NPC. Eleven patients were enrolled: one patient was assigned to arm A (adjuvant cusatuzumab monotherapy after curative chemoradiation), nine patients to arm B (cusatuzumab monotherapy; noncurative setting), and one patient to arm C (cusatuzumab + chemotherapy; noncurative setting); irrespective of tumoral CD70 expression. Both patients in arms A and C completed the study. All patients in arm B discontinued at an early stage. Five patients experienced grade greater than or equal to 3 nondrug related treatment-emergent adverse events, most commonly fatigue and pneumonia (18%). An infusion-related reaction was observed in two of 11 patients. Laboratory results showed no trend over time. Seven patients were eligible for response evaluation. No objective response to cusatuzumab was observed with stable disease being the best response. The current study indicates that the safety profile of cusatuzumab (with or without concurrent chemotherapy) is manageable in patients with advanced NPC, which is consistent with known safety profile. Limited activity of cusatuzumab in advanced NPC was observed. Combination therapies of cusatuzumab and other types of therapy should be explored for the improvement of activity in NPC and other CD70-expressing malignancies.

Prognostic markers in oropharyngeal squamous cell carcinoma: focus on CD70 and tumour infiltrating lymphocytes.

We evaluated the expression of CD70 as biomarker for prognosis in patients with oropharyngeal squamous cell carcinoma (OSCC). We also examined the prognostic value of tumour infiltrating lymphocytes (TILs) in our study cohort. Formalin fixed, paraffin embedded tissue originating from the oropharynx of 78 patients was immunohistochemically stained for CD70, CD3, CD8 and FoxP3. Expression of CD70, CD3, CD8, FoxP3 and HPV status was correlated with clinicopathological characteristics. Overall survival (OS) was determined by a log-rank (Mantel-Cox) test whereas the Cox proportional hazard model was used for multivariate analysis. CD70 expression demonstrated no influence on OS. Tumours heavily infiltrated by TILs were linked with better outcome, for the total number of TILs as well as for the CD3+ and CD8+ T cell count. A Cox proportional hazard model proved that solely CD8+ infiltrating T cells exhibit a positive effect on OS (HR=0.30, 95% confidence interval 0.13-0.72). Our results demonstrate that CD8+ TILs constitute an independent prognosticator in patients diagnosed with OSCC. Further validation of the prognostic value of CD8+ TILs in OSCC is warranted and could provide us with a better insight into the immunological status of these malignancies.

Turning the tide: Clinical utility of PD-L1 expression in squamous cell carcinoma of the head and neck.

The use of cytotoxic and/or targeted agents is the gold standard in first- and second-line treatment of metastatic head and neck cancer. Currently the focus of oncologic research is shifting to the implementation of immune checkpoint inhibitor regimens. Many trials are being performed evaluating the survival benefit of various PD-1/PD-L1 blocking antibodies in both solid and haematological malignancies. Also, evaluation of the predictive value of PD-L1 expression on tumour cells and immune cells is being explored. We first review the current knowledge and possible pitfalls for PD-L1 expression in squamous cell carcinoma of the head and neck. Next, we provide an update on the therapeutic use of PD-1/PD-L1 blocking antibodies as treatment modality for patients with squamous cell carcinoma of the head and neck and we assess the predictive value of tumour PD-L1 positivity. Finally, we elaborate on other promising predictive biomarkers of interest in this patient population.

TILs in Head and Neck Cancer: Ready for Clinical Implementation and Why (Not)?

The assessment of tumor infiltrating lymphocytes (TILs) has recently emerged as a prognostic biomarker in several solid tumors. Quantification and subtyping of TILs reflects the immune response in the tumor microenvironment, contributing to either tumoral immune attack or escape and thereby affecting outcome. Despite the growing evidence of its value as prognosticator, TILs analysis has not yet found its way to daily clinical practice. The aim of this review is to evaluate whether the current knowledge on TILs in head and neck cancer justifies its clinical implementation. Therefore, we summarize the data on TILs in squamous cell cancer of the head and neck with focus on the most important subsets (T lymphocytes and more specifically CD8+ cytotoxic T cells and FoxP3+ regulatory T cells) and site-specific characteristics such as Human Papilloma Virus infection. In addition, we discuss methodological problems and pitfalls that can account for discordant findings and that may hamper inclusion of TILs assessment in routine practice of pathologists and oncologists.

Tumor PD-L1 status and CD8+ tumor-infiltrating T cells: markers of improved prognosis in oropharyngeal cancer.

INTRODUCTION: The aim of this study was to evaluate the expression of PD-L1 in oropharyngeal squamous cell carcinoma. Its relation with clinicopathological variables, tumor infiltrating lymphocytes and survival was also determined. RESULTS: Positive PD-L1 status for the SP142 clone related with improved overall survival in oropharyngeal squamous cell carcinoma. Tumors heavily infiltrated by tumor infiltrating lymphocytes were also linked with better outcome, and this as well for the total number of tumor infiltrating lymphocytes as for the CD3+ and CD8+ T cell count. A Cox proportional hazard model proved that solely infiltrating CD8+ T cells exhibit a positive effect on overall survival (hazard ratio = 0.31 [0.14-0.70]; P = 0.0050). MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded tissue from oropharyngeal tumors of 99 patients was immunohistochemically stained for PD-L1 (SP142 and 22C3 clones), CD3, CD8 and FoxP3. Expression of PD-L1, CD3, CD8, FoxP3 and HPV status were correlated with clinicopathological variables. Overall survival was determined by a log-rank (Mantel-Cox) test whereas the Cox proportional hazard model was used for multivariate analysis. CONCLUSIONS: Our results demonstrate that CD8+ T lymphocytes constitute an independent prognostic marker in patients diagnosed with oropharyngeal squamous cell carcinoma. PD-L1 positivity for SP142, but not for 22C3, also tends to have a positive effect on survival in oropharyngeal squamous cell carcinoma.