ESTRO 37 Abstract book

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ESTRO 37

cancers were compiled. Descriptive statistics were calculated for all relevant demographic variables. Overall survival was estimated using a Kaplan-Meier method. Cumulative incidence of second malignancy was calculated; death was a competing risk. Results In total, 114 patients were evaluated. Median age at treatment was 71. There were 92 men and 22 women included. 89% had smoked more than 10 pack years and 54% were moderate to heavy drinkers. Median follow-up was 55.2 months. Overall survival at 1, 2, 3, 4 and 5 years was respectively 98, 96, 91, 88 and 83%. Relapse-free survival rates at 1,2,3,4 and 5 years were 91,90,88,85 and 85%. In total, 16 patients relapsed; 12 locally, 3 in regional lymph nodes and 1 with distant metastases. Mean time to relapse was 17.3 months. Second malignancies were identified in 21 of 114 (18%) patients and included bladder (2), CLL (1), colorectal (3), lung (9), prostate (3), and non-melanoma skin cancer (3). None were in-field and median time to second malignancy was 2.1 years, with cumulative incidence of developing second cancer of 17.3% (95% CI 0.100-0.264) at 5 years. Conclusion Our overall survival of 83% at 5 years and progression-free survival of 85% are acceptable. Most second cancers appeared outside the radiation field and the median time to diagnosis was much less than the expected time to second malignancy induction. Although longer follow-up is needed, increasing age, smoking and field-effect likely are key contributing factors. Lung cancer was the most common second malignancy and warrants screening in this population for early detection. EP-1163 Partial Laryngectomy vs Definitive Radiotherapy: 10 year-Outcomes in T2N0 Glottic Cancer L. Fonseca 1 , A. Mota 1 , E. Netto 1 , S. Esteves 2 , R. Pocinho 1 , M. Labareda 1 , F. Santos 1 , M. Magalhães 3 1 Instituto Português de Oncologia de Lisboa Francisco Gentil- EPE, Radiation Oncology Department, Lisboa, Portugal 2 Instituto Português de Oncologia de Lisboa Francisco Gentil- EPE, Clinical Research Unit, Lisboa, Portugal 3 Instituto Português de Oncologia de Lisboa Francisco Gentil- EPE, Otorhinolaryngology Department, Lisboa, Portugal Purpose or Objective The standard of care for early-stage glottic cancer (T2N0) includes primary surgery (PS), radiotherapy (RT) alone or with chemotherapy (CRT). PS and definitive RT seem to have similar efficacy. Our goal is to report the outcomes of patients treated in the last 10 years in our institution. Material and Methods We conducted a retrospective study by selecting clinical early-stage laryngeal cancer cT2N0 from a cancer centre database from January/ 2007 until June/2017. Inclusion criteria included age ≥ 18 years, squamous cell carcinoma histology, glottic and supraglottic laryngeal cancer, primary treatment includes partial laryngectomy/cordectomy, CRT or definitive RT. Fifty- five cases were excluded due to subglottic cancer, misclassified staging, M1, total laryngectomy or chemotherapy as primary treatment, missing data of primary treatment. Primary endpoints were Overall Survival (OS), Disease Free Survival (DFS) and Survival Free of Total Laryngectomy (SFTL). Major Adverse Cardiovascular Events (MACE) were registered after primary treatment. Kaplan-Meier survival curves were generated, log-rank test was used to detect differences between groups. Results Sixty-four from 119 patients were eligible for analysis, 62 males (97%) and 2 females (3%), with median age of 65

Figure: Kaplan–Meier plots: (A) Overall survival and (B) Distant free survival according to neck nodal metastasis. (C) Disease-specific survival and (D) Regional control according to elective nodal irradiation. Conclusion Neck nodal metastasis is associated with inferior disease- specific survival and maybe as a harbinger of distant metastases. Elective nodal irradiation provides wonderful regional control and may improve survival. EP-1162 Outcomes and second malignancies after radiotherapy for early stage glottis cancers S. Tisseverasinghe 1 , S. El-Sayed 2 , M. Thomas 2 , T. Zhang 3 , H. Vanasse 2 , S. Gupta 3 1 BC Cancer Agency - Southern Interior, Radiation Oncology, Kelowna, Canada 2 University of Ottawa and The Ottawa Hospital, Radiation Oncology, Ottawa, Canada 3 Ottawa Hospital Research Institute, Radiation Oncology, Ottawa, Canada Purpose or Objective Radiotherapy alone has been standard management for early stage glottis cancer for decades. Various fractionation regimens exist, but hypofractionation has been proven to lead to better outcomes. Second malignancy is a concern in these patients who have long life expectancies. We reviewed our experience to determine if radiotherapy was associated with an increase in the risk of second malignancies. Material and Methods We retrospectively reviewed consecutive patients treated with radiotherapy for T1-T2 glottis cancer between January 2006 and January 2013. From 2006, all patients with early glottis cancer received hypofractionated treatments at our regional tertiary center. 89%, received 52,0 Gy in 20 fractions over 4 weeks. 82% were treated with 6 MV photons and 18% with Cobalt using either wedged laterals or 3DCRT with 2-4 fields. Patients were treated supine with appropriate bolus, and immobilized with a thermoplastic shell. Patient information was stored in our head and neck registry database. Baseline characteristics, outcomes, types and dates of second