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 __________________________________________________________________________________________ well as to discuss their perspectives in the future. page 21

Keynote lecture

SP-036 Immunity and immune toxicity: clinical management of immune checkpoint inhibition U. Keilholz 1 1 Charité Comprehensive Cancer Center, Department of Medical Oncology, Berlin, Germany Abstract text Immunotherapy with immune checkpoint inhibitors is rapidly developing as the fifth treatment modality in concert with surgery, radiotherapy, chemotherapy, and targeted therapy. Relevant clinical activity and especially pong-tem responses have been observed in a variety of histologies, mainly in cancers with high mutational load. However, novel toxicities have also been observed, some of them requiring tight clinical and pharmacological management. In general, these toxicities are immune- mediated and resemble a minor form of graft-versus-host disease after allogeneic stem cell transplantation. Following tightly the established management guidelines, toxicities can be detected early on and usually be confined to low grade with minor impact on patient’s quality of life. The most important general principle is derived from the observation that more severe autoimmune toxicities require immunosuppressive medications, and that treatment of autoimmunity does not negatively impact on immune-mediated control of the neoplastic disease. Actually, many patients in whom severe autoimmune toxicities were observed and adequately managed belong to the group of patients with prolonged complete resolution of metastases. Organ systems most often affected by autoimmune toxicities include skin, liver, colon, lungs, kidneys and endocrine glands. While early recognition of toxicities to liver, kidney and endocrine glands can be achieved by monitoring liver enzymes, creatinine, TSH and cortisol, early recognition of colitis and pneumonitis require close clinical attention. In patients with diarrhea colonoscopy is indicated in case of pain or bloody stool. In patients with unexplained cough or shortness of breath, slight end-inspitatory rales may be the only clinical sign pointing towards extensive pneumonitis with profound infiltates on CT scan. Immediate and prolonged intervention with glucocorticoids, and sometimes immunosuppressive drugs is necessary to control these transient autoimmune reactions, only the endocrine toxicities may be permanent. SP-037 Immunotherapy beyond anti PD1 inhibitors P. Coulie 1 1 Université catholique de Louvain and de Duve Institute, Cellular Genetics, Brussels, Belgium Abstract text Immunostimulatory antibodies blocking the PD-1 co- inhibitory pathway have potent antitumor activity in a sizeable proportion of patients with various types of cancer. We will discuss the likely mechanism of action of these treatments, the proposed predictive biomarkers and the potential reasons for treatment failure. The latter include low tumor antigenicity, which in advanced cancer might result from previous immunoselections by antitumor T cells, poor immunogenicity of the tumor i.e. the absence of potent spontaneous antitumor T cell responses, and various mechanisms of local immunosuppression. Several of these mechanisms of tumor resistance to cancer immunotherapy with PD-1-blocking antibodies can be circumvented by drugs that are or will be tested soon in combination therapies.

SP-038 Clinical implementation of adaptive radiotherapy: challenges ahead O. Hamming-Vrieze 1 1 Netherlands Cancer Institute Antoni van Leeuwenhoek Hospital, Radiation Oncology, Amsterdam, The Netherlands Abstract text Intensity modulated radiotherapy is the standard of care in organ preserving treatment of head and neck cancer. Highly conformal dose distributions are optimized based on the anatomy of the pre-treatment planning CT. However, during treatment, accurate delivery of the planned dose can be influenced by anatomical changes which occur, especially by non-rigid anatomical changes for which set up protocols cannot correct. Anatomical changes during treatment may be related to change in tumor volume, weight, edema, muscle mass or fat distribution. Several studies have described changes of gross tumor volume (GTV) and organs at risk (OAR) in size, shape and position during a course of radiotherapy. In the presence of these anatomical changes, the actual delivered dose may differ significantly from the planned dose. Anatomical changes during treatment can be accounted for with adaptive radiotherapy (ART) where the radiation plan is adjusted during the course of treatment. In recent years, considerable efforts have been made to develop ART to compensate for under-dosage of the target volumes or over-dosage of OAR. Ideally, the treatment plan is adapted on a daily basis. At the moment however, the effort of re-imaging, re-contouring and re-planning does not outweigh the advantage and ART is not routinely used for all patients. Selection of the appropriate patients for ART remains a challenge, as well as the timing of re- scanning. Moreover, re-definition of target volumes raises the question whether the clinical target volume (CTV) can safely be adjusted to spare OAR. For instance, field size reduction following visible tumor regression assumes that microscopic disease in the CTV behaves congruent with changes in the visible GTV. These challenges for the clinical implementation of ART in head and neck cancer patients will be discussed in this presentation. SP-039 Adenoid cystic carcinoma: considerations in surgical approach and factors modifying expected outcome following treatment V. Vander Poorten 1 , J. Meulemans 2 , P. Delaere 3 1 University Hospitals Leuven - KU Leuven, Otorhinolaryngology- Head and Neck Surgery and Department of Oncology- section Head and Neck Oncology, Leuven, Belgium 2 University Hospitals Leuven- KU Leuven, Otorhinolaryngology- Head and Neck Surgery and Department of Oncology- section Head and Neck Oncology, Leuven, Belgium 3 University Hospitals Leuven- KU Leuven, Otorhinolaryngology- Head and Neck Surgery and Department of Oncology- section Head and Neck Oncology, Leuven, Belgium Primary surgery In AdCCs that are deemed resectable, the gold standard is free-margin resection with postoperative radiotherapy (RT). Clear margins are hard to achieve, given the Symposium: Adenoid cystic carcinoma