ESTRO 36 Abstract Book

S598 ESTRO 36 2017 _______________________________________________________________________________________________

surgery was performed in 51 (66%) and 48 (53%) cases and definitive radiochemotherapy was performed in 26 (34%) and 42 (47%) cases among p16 + and p16 - patients respectively (p=0.05). 99 patients (60%) underwent initial surgery followed by adjuvant radio (chemo) therapy in 51 cases (91 %). After a 51-month of median follow-up [47-54 months], the 3-year DFS was 82% and 42% among overall p16 + and p16 - patients respectively (p=0.01). Among p16 – patients, the 3-year DFS after initial surgery or definitive radiochemotherapy was 62% and 32% respectively (p=0.003). Among p16 + patients, the 3-year DFS was 85% and 77% (p=0.16) whereas severe delayed toxicity occurred in 42% vs. 18% after initial surgery or definitive radiochemotherapy respectively (p=0.05). Conclusion Whereas p16- OSSC are at high risk of loco-regional failure and highly benefited from aggressive multimodal treatment including surgery and adjuvant radio(chemo)therapy, p16+ OSCC didn’t harbour the same benefit from the combinative approach that was associated with a significant increase of delayed severe toxicity. The benefit of initial surgery or definitive radio(chemo) therapy seemed not equivalent among OSSC patients according to p16 status that might be a useful tool to guide initial treatment decision. EP-1098 Survival predictors in patients with head and neck cancer treated with surgical resection R.C.D.O. Franco 1 , L.L. De Matos 2 , G. De Castro Junior 3 , M.A.V. Kulcsar 2 , G.N. Marta 1,4 1 Instituto do Câncer do Estado de São Paulo ICESP - Faculdade de Medicina da Universidade de São Paulo, Radiation Oncology, Sao Paulo, Brazil 2 Instituto do Câncer do Estado de São Paulo ICESP - Faculdade de Medicina da Universidade de São Paulo, Division of Head and Neck Surgery, Sao Paulo, Brazil 3 Instituto do Câncer do Estado de São Paulo ICESP - Faculdade de Medicina da Universidade de São Paulo, Clinical Oncology, Sao Paulo, Brazil 4 Hospital Sírio-Libanês, Radiation Oncology, São Paulo, Brazil Purpose or Objective This study aims to identify clinical factors that impact on overall survival of head and neck squamous cell carcinoma (HNSCC) patients who received surgery and post-operative radiation therapy (RT), with or without adjuvant chemotherapy. Material and Methods Between 2009 and 2013, patients diagnosed with HNSCC who underwent surgical resection with curative intent, followed by post-operative RT, with or without concurrent cisplatin-based adjuvant chemotherapy were assessed. Cox regression analyses were performed to evaluate the clinical and pathological features that could influence overall survival rates. Results 170 patients were included (75.3% male). Oral cavity, larynx and oropharynx cancer were represented by 57.4%, 30.8% and 11.8% of all patients. Most patients (90.6%) had locally advanced disease (stage III or IV). Perineural and lymphovascular involvement were found in 70% and 31%, respectively. Free surgical margins were observed in 84% of cases and 66% had positive lymph nodes, 57% with extracapsular extension. 92.0% of patients received at least 60 Gy to the tumor bed. 45.0% of patients received concurrent chemotherapy. After a 23-month median follow-up, the overall survival rate was 60.7%. At univariate analysis, perineural invasion (p = 0.025), positive lymph nodes (p = 0.011), extracapsular extension (p = 0.005), radiation dose less than 60 Gy to tumor bed (p=0.000) and stage IV (versus stage III) [p= 0.007] negatively impacted on the overall survival. Multivariate analysis demonstrated that presence of extracapsular

extension (p=0.005) and stage IV (p=0.01) were independent predictors of a lower overall survival rate. Conclusion The main factors that negatively affected overall survival rates in HNSCC patients treated with surgery with curative intent and post-operative radiation therapy with or without concurrent cisplatin-based adjuvant chemotherapy were the presence of extracapsular extension and stage IV disease. EP-1099 Evaluation of laryngeal preservation & outcomes following RT for locally advanced laryngeal SCC A.M. Glynn 1 , J. O Shea 1 , R. McDermott 1 , S. Brennan 1 1 St Lukes Radiation Oncology Network, Radiation Oncology, Dublin, Ireland Purpose or Objective To assess failure rates and to evaluate functional outcomes in patients treated with radical radiotherapy for locally advanced laryngeal cancer based on cartilage invasion status Material and Methods A retrospective analysis of sixty-four patients who received radiotherapy (70Gy) with or without platinum- based chemotherapy for locally advanced SCC of the larynx from January 2010 to December 2015 at St Luke’s Radiation Oncology Network, Dublin, Ireland. Patients were categorised according to the degree of cartilage invasion based on radiological staging as having no cartilage invasion (T2/T3), minimal cartilage invasion (T3+) or gross cartilage invasion (T4) Results Sixty-four patients all receiving 70Gy using intensity- modulated radiation therapy techniques (IMRT) were analysed. Median age was 62.7 years. Eighty percent were males and 20% females. Thirty eight (59%) were smokers at the time of diagnosis and 89% (n=34) continued to smoke during their treatment. Ninety two percent underwent PET-CT and 52% had MRI staging prior to commencing radiotherapy. Thirteen percent (n=8) were staged as T2, 54.7% (n=35) were T3, 20.3% (n=13) were T3+ and 12.5% (n=8) were T4. Median time from biopsy date to radiotherapy start date was 7.2 weeks. Two thirds (n=42) had chemotherapy. Median follow-up time was 6.5 months. Median survival was 23.6 months. Forty seven percent (n=30) documented failures were identified and median time to failure was 4.5 months. Of those who failed 53% (n=16) failed locally, 27 %( n=8) failed regionally, 7%(n=2) failed loco-regionally and 13 %( n=4) failed distantly. Furthermore seven percent of those who failed had T2 disease (n=2), 50% had T3 (n=15), 23% had T3+ (n=7) and 20% had T4 (n=6). Thirty nine percent (n=26) had PEG tubes inserted, of which 20 had them inserted pre-RT. Based on last follow-up appointment our overall PEG dependence rate was 27%. Thirty-four percent (n=21) had tracheostomy tubes, of which 15 had them inserted pre-RT. Our overall tracheostomy dependence rate was 23% Conclusion Traditionally cartilage invasion is considered an indication for surgical management of laryngeal cancer. With the reclassification of minor thyroid cartilage invasion as T3, it is more difficult to decide which patients should be treated with radiotherapy as part of a laryngeal preservation approach. Our evaluation did not show a significant difference in failure rates in terms of cartilage invasion status. Our results show comparable outcomes with recent up-to-date literature in terms of PEG and tracheostomy rates EP-1100 Nodal Response During Radiotherapy for Head and Neck Cancer Correlates with Outcome