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 73

was 77% vs. 79%, for Y vs. O, respectively. Local control was significantly correlated with T stage (T2 89%, T3 80%, T4 56%), mobility of the vocal cord (87%, 90% and 71% for normal, impaired, and fixed cord, respectively). In multivariate analysis the only independent prognostic factor for local control was T-stage. Tube feeding during treatment was given in 24%, equal for both age groups. Severe late toxicity (PEG tube and/or tracheotomy dependency) after 2 years was 10% and 12% for Y and O respectively. In multivariate analysis severe late toxicity was related to yes or no tube feeding dependency during treatment, need for tracheotomy or debulking before treatment, and field size. Conclusion In this large group of patients treated with accelerated fractionation for intermediate size head and neck tumor age ≥ 70 was not a negative prognostic factor for local control, disease free survival and risk of complications. For patients ≥ 70, with a WHO performance 0-1 with our fractionation schedule excellent outcome is shown. 1: Terhaard CH, Kal HB, Hordijk GJ. Int J Radiat Oncol Biol Phys. 2005 May 1;62(1):62 PO-151 Immunotherapy for refractory brain metastasis in cases of oropharangeal squamous cell carcinoma M. Bhandari 1 , P. Vora 2 , A. Dugar 3 , S. Bhati 4 , A. DeFranco 5 , E. Guenther 6 1 The Christ Hospital, Medical Oncology, Cincinnati- OH, USA 2 The Christ Hospital, Medical Oncology, Cincinnati-OH, USA 3 Wellesley College, Biology, Boston- MA, USA 4 Miami University, Biology, Oxford- OH, USA 5 Cornell Medical School, Biology, New York- NY, USA 6 The Christ Hospital, Rad Oncology, Cincinnati -OH, USA Purpose or Objective To investigate the efficacy and tolerability of checkpoint inhibition in cases of progressive CNS/brain metastasis from squamous cell carcinoma of the head and neck after optimal radiation therapy. Brain metastasis from head and neck squamous cell carcinoma (HNSCC) is a unfortunately clinical entity and can occur in HPV positive as well as smoking associated, HPV negative HNSCC. Disease progression after optimal radiation therapy to the sites of brain metastasis is difficult to control and has almost no viable therapeutic options. These patients are often recommended hospice based supportive care only. Herein, we investigate and report the case series of the first 3 patients with disease progression post-optimal radiotherapy revealing disease control beyond median of 6 months utilizing systemic immunotherapy with pembrolizumab (Ketruda R , Merck). Material and Methods Institution approved, compassionate access program guided therapy utilizing pembrozulimab (Ketruda) at 2mg/kg every 3 weeks until disease progression or intolerable toxicity. Results We report a case series of the first 3 patients treated with metastatic squamous cell carcinoma of oropharynx with brain metastasis in our institutional protocol. Patients were treated upon disease progression in CNS post optimal radiotherapy. Two patients had HPV negative, smoking associated primary HNSCC prior to development of systemic relapse and CNS metastasis and one patient had HPV positive primary HNSCC. One smoking associated Poster: Immunodiagnosis and immunotherapy

HNSCC patient has stayed on continuous therapy beyond 1 year with no CNS or systemic disease progression and with radiographic evidence of CNS disease regression. Two other patients have stayed on therapy for 9 and 6 months respectively, with one experiencing disease progression at the 7 th month of therapy. Overall disease control rate & data from further patients enrolling this study will be reported in this small case series. The first 3 patients have a median time to disease progression of over 8 months, which is unprecedented in these clinical settings. Responses are seen irrespective of PD-1 staining, but all three patients had a gene signature of high tumor mutation burden (TMB). Conclusion Checkpoint inhibitors may have a large role to play as salvage therapy or as maintenance post primary radiotherapy for CNS metastasis from HNSCC. Disease control is seen so far in smoking and HPV associated HNSCC brain metastasis. Tumor mutation burden has been found to predict clinical disease control, rather than IHC for PD- 1 or PDL-1 in our single instruction case series. Further clinical trials of immunotherapy for CNS metastasis from HNSCC is warranted.