6th ICHNO Abstract Book

page 52 6 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 16 – 18 March 2017 Barcelona, Spain __________________________________________________________________________________________ Material and Methods 6th ICHNO

colorimetric assay quantitatively measures lactate dehydrogenase (LDH), a stable cytosolic enzyme that is released upon cell lysis. Released LDH in culture supernatants were measured using a coupled enzymatic assay, which resulted in the conversion of a tetrazolium salt (INT) into a red formazan product. Results We observed that TLR3 as well as TLR4 agonists resulted in significantly increased expression levels of PD-L1 in permanent HNSCC cell lines. These data could be corroborated by immunohistochemical analyzes of the sub-cellular PD-L1 expression in response to TLR stimulation. Increased expression of PD-L1 correlated with modulated NK-cell activities and strongly affected cytolysis of the analyzed target cells. Conclusion When considering innovative antibody-based immunotherapy approaches, check-point regulators such as the PD-1/PD-L1 pathway have recently shown very promising results. Our data underline the requirement of combined therapeutic strategies, namely to inhibit the PD1 function on the immune cell side as well as to block the TLR dependent up-regulation of check point inhibitors on the tumor side. PO-109 The added value of SPECT-CT for identification of sentinel lymph nodes in early stage oral cancer I. Den Toom 1,2 , A. Van Schie 3 , S. Van Weert 2 , O. Hoekstra 3 , H. Karagozoglu 4 , E. Bloemena 4,5 , R. De Bree 1,2 1 UMC Utrecht, Head and Neck Surgical Oncology, Utrecht, The Netherlands 2 VU University Medical Center, Otolaryngology-Head and Neck Surgery, Amsterdam, The Netherlands 3 VU University Medical Center, Radiology and Nuclear Medicine, Amsterdam, The Netherlands 4 VU University Medical Centre/Academic Center for Dentistry, Oral and Maxillofacial Surgery / Oral Pathology, Amsterdam, The Netherlands 5 VU University Medical Center, Pathology, Amsterdam, The Netherlands Purpose or Objective To assess the role of Single Photon Emission Computed Tomography with Computed Tomography (SPECT-CT) for the identification of sentinel lymph nodes (SLNs) in patients with early stage (T1-T2) oral cancer and a clinically negative neck (cN0). Material and Methods In addition to planar lymphoscintigraphy SPECT-CT was performed in 66 consecutive patients with early stage oral cancer and a clinically negative neck. The addition of SPECT-CT to planar images was retrospectively analysed for the number of additional SLNs, more precise localisation of SLNs and importance of anatomical information by a team consisting of a nuclear physician, surgeon and investigator. Results Identification rate for both imaging modalities combined was 98% (65/66). SPECT-CT identified 15 additional SLNs in 14 patients (22%). In 2/15 (13%) of these additional SLNs the only metastasis was found, resulting in an upstaging rate of 3% (2/65). Figure 1 shows an example of an additional SLN level II on the left side (arrow) on SPECT- CT. In 20% of the patients with at least one positive SLN the only positive SLN was detected due to the addition of SPECT-CT. SPECT-CT was considered to add important anatomical information in 2 patients (3%). In 5/65 (8%) of the patients initially scored SLNs on planar Poster: Imaging and radiomics

We performed a retrospective analysis of patients with non-nasopharyngeal, non-OPSCC and known HPV status identified in the NCDB. Patient characteristics and survival data were analyzed by univariate and multivariate analyses using Cox proportional hazards regression and the log-rank test within Kaplan-Meier analysis. Results A total of 27,160 patients with known HPV status were identified of which 8,672 (32%) were HPV- positive. Patients with HPV-positive disease were more likely to be male, younger, and present with an oral cavity primary, greater nodal burden and higher overall clinical stage than HPV-negative patients (p < 0.01). On multivariate analysis, factors predictive of worse overall survival included age ≥ 65 years (HR: 1.45; 95% C.I. 1.34- 1.57; p < 0.001), Charlson/deyo comorbidity score of 1 (HR: 1.10; 95% C.I. 1.01-1.20; p < 0.05) and ≥ 2 (HR: 1.78; 95% C.I. 1.57-2.02; p < 0.001), non-private/unknown insurance (HR: 1.41; 95% C.I. 1.30-1.54; p < 0.001), hypopharynx subsite (HR: 1.23; 95% C.I. 1.09-1.38; p < 0.01), tumor size (HR: 1.19; 95% C.I. 1.16-1.22; p < 0.001), increasing nodal stage (N1 = HR: 1.19; 95% C.I. 1.06-1.33; p < 0.01), (N2 = HR: 1.16; 95% C.I. 1.05-1.29; p < 0.01), (N3 = HR: 1.66; 95% C.I. 1.20-2.28; p < 0.01), and HPV- negative status (HR: 2.01; 95% C.I. 1.83-2.21; p < 0.001). Unadjusted 2-year overall survival for patients with HPV-positive and HPV-negative disease according to stage was: Stage I 92% vs. 88%, Stage II 86% vs. 75%, Stage III 88% vs. 68%, Stage IVA 85% vs 60%, and Stage IVB 68% vs 46%. Conclusion Patients with HPV-positive non-OPSCC exhibit similar patient and disease characteristics as those previously described for patients with HPV-positive OPSCC. Overall survival was significantly influenced by HPV status. As such patients with HPV-positive non-OPSCC disease represent are favorable cohort that warrant further investigation. PO-108 TLR induced PDL-1 expression in HNSCC as a potential tool of immunomodulation B. Wollenberg 1 , R. Pries 1 , M. Drenckhahn 1 , K. Ploetze- Martin 1 , B. Wollmann 1 1 University of Lübeck, Otorhinolaryngology- Head and neck surgery, Lubeck, Germany Purpose or Objective Head and neck squamous cell carcinoma (HNSCC) is one of the most common solid neoplasms worldwide. Its occurrence is being associated with exposure to smoking and alcohol consumption. Even though enormous progress concerning the treatment of HNSCC has been made, the mortality rates are still high due to local tumor invasion, development of metastases and failure of chemo- and radiation therapies. In Neuroblastoma it has been shown that specific antibody targeting of PD-L1 leads to increased anti-tumor functions of T-lymphocytes, whereas triggering with the TLR3 ligand Poly I:C leads to a strong up regulation of PD-L1. We therefore asked whether Toll-like receptors act as PD/PD- L1 regulators in HNSCC and which consequence this finally has for the immuno-activity of natural killer (NK-) cells. Material and Methods Different established HNSCC cell lines were treated with the TLR3 ligand Polyinosinic:polycytidylic acid (PolyI:C) and TLR4 ligand LPS through both extracellular and intracellular ways. PD-L1 expression was analyzed on the mRNA- as well as on the protein level using RT-PCR and Western hybridization experiments. NK cells were analyzed for cytolytic activity using the CytoTox-96 Non- Radioactive Cytotoxicity Assay (Promega). This