7th ICHNO Abstract book

7th ICHNO 7 th ICHNO Conference International Conference on innovative approaches in Head and Neck Oncology 14 – 16 March 2019 Barcelona, Spain __________________________________________________________________________________________ page 53

Upfront surgery is a valuable treatment option for oropharyngeal squamous cell carcinoma (OPSCC) independent of HPV-status. Risk stratification is emerging for treatment de-escalation in HPV-related OPSCC. However, most risk models are based on selected Patient cohorts. To evaluate the clinical significance of HPV and further prognostic factors we used recursive partitioning analysis (RPA) to generate a risk-model for unselected patients with OPSCC after treatment including upfront surgery. Material and Methods All patients diagnosed with OPSCC and treated with curative intent between 2000 and 2009 (n=359) were included. HPV-association was determined by HPV-DNA detection and p16 INK4a immunohistochemistry. Overall survival (OS) and prognostic impact of risk factors, patient´s and clinical characteristics were estimated by the Kaplan-Meier method and Cox regression. Predictors with significant impact on survival were included in RPA. Results A new model was developed for unselected patients treated with upfront surgery separating patients with significant differences in OS (5-year OS: 86%, 53% and 19%, P<.001 for low-/intermediate- and intermediate/high- risk). HPV-status is the most important predictor followed by T-stage in HPV-related OPSCC and performance status in HPV-negative OPSCC. N-stage and age are further parameters in the HPV-negative OPSCC only. HPV-status and ECOG remained important parameters in risk-models for patients treated with or without surgery. Conclusion HPV-status is the strongest predictor of survival in unselected OPSCC patients irrespective of treatment modality. The proposed risk models can be used to discriminate risk groups in unselected patients with OPSCC and treated with primary surgery, which has substantial impact for designing and interpretation of de-escalation trials. PO-105 UICC TNM 8th Edition Staging in Oropharyngeal Cancer: Validation in a UK Single Centre Cohort Abstract withdrawn PO-106 Intratumor heterogeneity of PD-L1 expression in Head and Neck squamous cell carcinoma J. Rasmussen 1 , G. Lelkaitis 2 , K. Håkansson 3 , I.R. Vogelius 3 , H.H. Johannesen 4 , B.M. Fischer 4 , L. Specht 3 , C.A. Kristensen 3 , C.V. Buchwald 1 , I. Wessel 1 , J. Friborg 3 1 Rigshospitalet- University of Copenhagen, Department of Otorhinolaryngology- Head and Neck Surgery and Audiology, Copenhagen, Denmark; 2 Rigshospitalet- University of Copenhagen, Department of Pathology, Copenhagen, Denmark; 3 Rigshospitalet- University of Copenhagen, Department of Oncology- Section of Radiotherapy, Copenhagen, Denmark; 4 Rigshospitalet- University of Copenhagen, Department of Clinical Physiology- Nuclear Medicine and PET- PET and Cyclotron Unit, Copenhagen, Denmark Purpose or Objective Intratumor heterogeneity may contribute to the ambiguous results on PD-L1 status seen in the clinical studies of patients with head and neck squamous cell carcinoma (HNSCC). This challenge the use of PD-L1 expression from single tumor biopsies as a predictor for immunotherapy. In this prospective study, intratumor heterogeneity of PD-L1 expression in HNSCC was investigated. Material and Methods

PO-103 Competing mortality in oropharyngeal carcinoma according to HPV status J.M. Costa González 1 , J. Lop 2 , J. García 3 , M. López 3 , M. Taberna 4 , M. Mena 5 , L. Alemany 6 , A. Sumarroca 1 , M. Quer 3 , Broggi, Otorhinolaryngology, Sant Joan Despí, Spain; 2 Hospital Parc Taulí, Otorhinolaryngology, Sabadell, Spain; 3 Hospital de Sant Pau, Otorhinolaryngology, Barcelona, Spain; 4 Medical Oncology Department- Catalan Institute of Oncology ICO- IDIBELL, Medical Oncology, L’Hospitalet de Llobregat, Spain; 5 Cancer Epidemiology Research Program- Catalan Institute of Oncology ICO- IDIBELL, Cancer Epidemiology Research Program- Catalan Institute of Oncology ICO- IDIBELL, L’Hospitalet de Llobregat, Spain; 6 Cancer Epidemiology Research Program- Catalan Institute of Oncology ICO- IDIBELL, Cancer Epidemiology Research Program- Catalan Institute of Oncology ICO- IDIBELL, L'Hospitalet de Llobregat, Spain Purpose or Objective The objective of the present study is to assess differences in the competing causes of death in oropharyngeal carcinoma (OPC) patients as a function of the HPV status. Material and Methods We studied retrospectively 423 OPC patients with known HPV-status. Among the patients included in the study, 53 (12.5%) were HPV-positive. We analyzed overall survival and competing causes of mortality according to the HPV status of the patients. Results Patients with HPV-negative tumors had lower OPC cancer- specific survival (P=0.0001), second primary neoplasm survival (P=0.0001), and noncancer related causes survival (P=0.125) than patients with HPV-positive tumors. This resulted in significant differences in overall survival depending on HPV status (P=0.0001). Conclusion HPV-positive OPC have a better overall survival than HPV- negative OPC. Patients with HPV- positive tumors presented a significant lower OPC cancer-specific and second primary neoplasm mortality, and a marginally non- significant lower noncancer mortality as compared to HPV- negative tumors. PO-104 Predictors for an improved survival in surgically treated patients - Risk stratification in OPSCC N. Würdemann 1 , S. Wagner 2 , C. Wittekindt 3 , S.J. Sharma 4 , M. Reuschenbach 5 , E. Prigge 5 , M. Von Knebel-Doeberitz 5 , S. Gattenlöhner 6 , E. Burkhardt 7 , J. Pons-Kühnemann 7 , J.P. Faculty, Otorhinolaryngology- Head and Neck Surgery, Cologne, Germany; 2 University of Giessen, Department of Otorhinolaryngology- Head and Neck Surgery, Giessen, Germany; 3 University of Giessen/Germany, Department of Otorhinolaryngology- Head and Neck Surgery, Giessen, Germany; 4 University of Cologne-Medical Faculty, Department of Otorhinolaryngology- Head and Neck Surgery, Cologne, Germany; 5 University Hospital Heidelberg, Department of Applied Tumour Biology- Institute of Pathology, Heidelberg, Germany ; 6 University of Giessen, Department of Pathology, Giessen, Germany; 7 University of Giessen, Institute of Medical Informatics, Giessen, Germany X. León 3 1 Hospital Sant Joan Despí Moisès Klußmann 4 1 University of Cologne- Medical

Purpose or Objective