6th ICHNO Abstract Book

6th ICHNO 6 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 16 – 18 March 2017 Barcelona, Spain __________________________________________________________________________________________ page 49

Pretreatment OPN levels were higher in patients with advanced T stage compared with early stage (p=0.024). There was no correlation between N stage and OPN (p=0.58). Median plasma levels of OPN measured before (67.9 ng/ml) and after (97.8 ng/ml) treatment differed (p=0.0001). OPN levels before treatment were significantly related to overall survival (OS) ratio in both, univariate (p=0.019) and multivariate analysis (0.001). Posttreatment OPN levels (97.8 ng/ml) were also associated with survival time in univariate analysis (p=0.04). Additionally, OPN after treatment was significantly higher in patients with distant metastasis High levels of OPN before therapy have been associated with advanced stage and adverse prognosis. OPN after therapy may play important role in the process of tumor development and metastasis. OPN concentrations increase during treatment may reflect acute mucosal reaction after radiotherapy. Pretreatment OPN is an independent prognostic determinant of survival. PO-102 EGFR detection in saliva as an easy diagnostic and prognostic tool in oral squamous cell cancer C. Piazza 1 , A. Paderno 1 , L. Zanotti 2 , E. Bandiera 2 , F. Del Bon 1 , C. Romani 2 , P. Perotti 1 , E. Bignotti 2 , N. Montalto 1 , R. Morello 1 , F.E. Odicino 2 , P. Nicolai 1 , A. Ravaggi 2 1 University of Brescia, Otorhinolaryngology - Head and Neck Surgery, Brescia, Italy 2 University of Brescia, "Angelo Nocivelli" Institute of Molecular Medicine - Division of Gynecologic Oncology, Brescia, Italy Purpose or Objective Epidermal growth factor receptor (EGFR) is a type I transmembrane glycoprotein widely expressed on epithelial cells and required for their development and proliferation. The extracellular domain of EGFR can be released by proteolytic cleavage and shed from tumor cells surface, thus representing a potential tumor marker. EGFRs have been frequently found to be overexpressed in a wide variety of malignancies, including oral squamous cell carcinoma (OSCC). Our objective was to assess the EGFR diagnostic and prognostic values in OSCC, investigating its expression in serum and saliva of a homogeneous group of patients in comparison with that of healthy subjects. Material and Methods Serum and saliva samples were collected from a cohort of OSCC patients before surgery and a matched group of healthy subjects. A written consent was obtained in all cases. Serum EGFR concentration was determined by an enzyme-linked immunosorbent assay (ELISA), according to manufacturer’s instructions. Saliva EGFR concentration was determined with a modified protocol of the same immunoassay. Sixty-three naïve patients affected by OSCC (cases) and 60 healthy individuals (controls) were included in the study. Results Regarding serum EGFR levels, OSCC patients (mean, 47.6 ng/ml; range, 29.9-82.5) evidenced significantly lower values (p<0.001) when compared with controls (mean, 53.7 ng/ml; range, 38.6-70.7). Conversely, salivary EGFR concentrations were significantly higher (p=0.001) in OSCC patients (mean, 8.2 ng/ml; range, 0.9-37.8) than in controls (mean, 4.4 ng/ml; range, 0.6-20.6). Salivary EGFR levels were also significantly related with tumor pT classification (p=0.02). Considering 9.0 ng/ml (75° percentile) as the cut-off, patients with higher values of salivary EGFR had a worse prognosis in terms of disease specific survival (p=0.017) (Fig. 1), even when limiting the evaluation to pT4 tumors only (p=0.05). (p=0.015). Conclusion

Conclusion Salivary EGFR can be considered a potential tumor marker for OSCC detection, with both diagnostic and prognostic values. Serum EGFR, on the other hand, was significantly lower in patients but did not show any prognostic impact. Determination of these markers requires a non-invasive sampling procedure and is based on a low-cost technique. PO-103 Oropharyngeal cancer patient-derived xenografts: Characterization and radiosensitivity. J. Lilja-Fischer 1 , B. Ulhøi 2 , J. Alsner 1 , P. Lassen 1 , V. Nielsen 3 , J. Overgaard 1 1 Aarhus University Hospital, Department of Experimental Clinical Oncology, Aarhus, Denmark 2 Aarhus University Hospital, Department of Pathology, Aarhus, Denmark 3 Aarhus University Hospital, Department of Otorhinolaryngology, Aarhus, Denmark Purpose or Objective Oropharyngeal squamous cell carcinoma (OPSCC) is now the most common type of head and neck cancer. HPV, tobacco smoking or a combination of the two are the major etiologic factors. After radiotherapy-based treatment, prognosis is superior for patients with purely HPV-associated OPSCC compared to patients with tobacco-associated HPV-negative disease. As an explanation, it has been hypothesized that HPV- associated tumors are more radiosensitive. Patients with overlapping etiologies (i.e., both HPV and tobacco smoking) appear to have an intermediate prognosis, something that is currently unexplained. Since OPSCC is heterogeneous in disease biology and treatment sensitivity, further personalization of treatment is needed, which is the focus of ongoing clinical trials. However, adequate pre-clinical models and biomarkers reflecting treatment sensitivity are lacking. Purpose of this study was to create a number of patient- derived xenografts (PDX) reflecting the heterogeneity of OPSCC and compare the models with the corresponding original human tumors. Also, we wished to determine if the PDX model is suitable for radiotherapy research. Material and Methods Fresh tumor biopsies from patients with primary, untreated OPSCC were implanted subcutaneously in immunodeficient mice. PDX tumors were serially transplanted and expanded, producing generations of PDX tumors with identical origin. Xenograft tumors and human originals were compared using histology and immunohistochemistry for p16, cytokeratin AE1/AE3 and CD45. To characterize radiosensitivity, PDX tumors were subjected to low-dose irradiation in a growth delay assay (4 - 8 Gy, single fraction).