ESTRO 38 Abstract book

S257 ESTRO 38

Results between 8/2014 and 2/2018, 108 patients were randomized. The median follow-up was 12.3 months. After 64 events, the intention-to-treat analysis showed a 2- year OS rate of 58% in the RHR arm vs. 28% in the PR arm (p=0.003). Data on other clinical end-points will be presented. Factors associated with increased survival at the multivariate analysis were RHR (HR=0.46)and epithelioid histology (HR=0.33). In the RHR arm the documented considerable toxicities were the following: Grade 5 pneumonitis n=1, Grade 3 pneumonitis n=4, pulmonary embolism n=4; pericardial effusion n=2; rib fractures n=2, Grade 3 erithema n=1, Grade 3 esophagitis n=1, and Grade 3 GGT increase n=3. Late respiratory failure requiring oxygen was documented in 4 patients. Conclusion RHR increases survival in MPM patients who undergo non- radical surgery and chemotherapy, with acceptable toxicity. RHR should be considered the new standard of care in this clinical setting. OC-0501 Chemo-RT plus induction or consolidation chemotherapy for rectal cancer: a randomised phase 2 trial E. Fokas 1 , M. Allgäuer 2 , B. Polat 3 , G. Klautke 4 , G. Grabenbauer 5 , R. Fietkau 6 , T. Kuhnt 7 , L. Staib 8 , T. Brunner 9 , A.L. Grosu 10 , W. Schmiegel 11 , L. Jacobasch 12 , J. Weitz 13 , G. Folprecht 14 , A. Schleska-Lange 15 , R. Grützmann 16 , M. Schwarzbach 17 , V. Paolucci 18 , W.O. Bechstein 19 , T. Friede 20 , M. Ghadimi 21 , R.D. Hofheinz 22 , C. Rödel 1 1 University Of Frankfurt, Department Of Radiotherapy And Oncology, Frankfurt, Germany ; 2 Barmherzige Brüder Hospital Regensburg, Department Of Radiotherapy, Regensburg, Germany; 3 University Of Würzburg, Department Of Radiation Therapy, Würzburg, Germany ; 4 poliklinik Chemnitz Gmbh, Department Of Radiation Therapy, Chemnitz, Germany ; 5 Diacura and Klinikum Coburg, Department of Radiation Oncology And Radiotherapy, Coburg, Germany ; 6 University Of Erlangen-Nürnberg, Department of Radiation Therapy, Erlangen, Germany ; 7 university Of Leipzig, Department Of Radiation ThUrapy, Leipzig, Germany ; 8 Klinikum Esslingen, Department Of General And Visceral Surgery, Esslingen, Germany ; 9 University Of Freiburg, Department of Radiation Therapy, Freiburg, Germany ; 10 Department of Radiation Therapy, University of Freiburg, Freiburg, Germany ; 11 Ruhr-University Bochum, Department Of Haematology and Oncology, Bochum, Germany ; 12 Clinic Of Haematology and Oncology Dresden, Deparment of Haematology and Oncology, Dresden, German ; 13 University of Dresden, Department of General and Visceral Surgery, Dresden, Germany ; 14 University Of Dresden, Department of Haematology and Oncology, Dresden, Germany ; 15 Barmherzige Brüder Hospital Regensburg, Department of Haematology and Oncology, Regensburg, Germany; 16 university Of Erlangen-Nürnberg, Department of General And Visceral Surgery, Erlangen, Germany ; 17 klinikum Frankfurt Höchst, Department Of General and Visceral Surgery, Frankfurt, Germany ; 18 ketteler Krankenhaus Offenbach, Department of General and Visceral Surgery, Offenbach, Germany; 19 University of Frankfurt, Department Of General And Visceral Surgery, Frankfurt, Germany ; 20 University Medical Center Göttingen, Department of Medical Statistics, Göttingen, Germany ; 21 University Medical Center Göttingen, Department of General and Visceral Surgery, Göttingen, Germany; 22 University Hospital Mannheim, Department of Medical Oncology, Mannheim, Germany Purpose or Objective Total neoadjuvant therapy (TNT) is a new paradigm for locally-advanced rectal cancer treatment. Two TNT

P=0.001), the cumulative incidence of distant metastasis (HR 1.957; 95% CI 1.388-2.761; P<0.001) and overall survival (OS; HR 2.161; 95% CI 1.507-3.10; P<0.001) in multivariable analysis. Similar significant findings were observed for leukocytosis and high CEA levels, whereas thrombocytosis was an independent prognostic factor for local recurrence (HR 2.731; 95% CI 1.308-5.701; P=0.007) in multivariable analysis. Conversely, treatment-induced leukopenia correlated with significantly better DFS (P=0.037). Addition of oxaliplatin to 5-FU CRT resulted in a significant DFS improvement only in patients with neutrophilia and leucocytosis (both P=0.005). Conclusion We here demonstrate that peripheral blood leukocytosis and neutrophilia were associated with adverse clinical outcome in patients with rectal cancer treated within the CAO/ARO/AIO-04 phase 3 trial. Our findings have important implications for the daily clinical practice and provide high-level evidence on the prognostic role of leukocytes and neutrophils. These data could help guide patient stratification to escalation or de-escalation strategies, also as part of the increasingly explored concept of non-operative management, and provide a rationale for neutrophil inhibition with CRT and chemotherapy in future trials in rectal cancer. OC-0500 Radical Hemi-thoracic Radiotherapy vs. Palliative Radiotherapy for Malignant Pleural Mesothelioma. E. Minatel 1 , M. Trovo 2 , J. Polesel 1 , C. Furlan 1 , A. Revelant 1 , A. Drigo 1 , L. Barresi 1 , A. Bearz 1 , A. Del Conte 1 , A. Follador 3 , U. Zuccon 4 , A. Dicorato 5 , P. Fontana 6 , G. Franchin 1 1 Centro Di Riferimento Oncologico, Radiation Oncology, Aviano, Italy ; 2 azienda Sanitaria Universitaria Integrata Udine, Radiation Oncology, Udine, Italy; 3 Azienda Sanitaria Universitaria Integrata Udine, Medical Oncology, Udine, Italy; 4 Pordenone General Hospital, Pneumology, Pordenone, Italy; 5 Azienda Sanitaria Universitaria Integrata Trieste, Medical Oncology, Trieste, Italy; 6 Mestre General Hospital, Thoracic Surgery, Mestre, Italy Purpose or Objective The present phase III randomized trial wants to compare the overall survival (OS) of patients treated with radical hemithoracic radiotherapy (RHR) vs. palliative radiotherapy (PR), after non-radical lung-sparing surgery and chemotherapy in malignant pleural mesothelioma (MPM) patients. Material and Methods Patients were randomized to receive either radiotherapy to the entire hemithorax excluding the intact lung to a dose of 50 Gy in 25 fr. + a simultaneous boost to 60 Gy to areas of gross disease, or palliative radiotherapy (PR) (20- 30 Gy in 5-10 fr.) to thoracotomy scars or to the gross disease only. Before randomization all patients had to be treated with non-radical lung-sparing surgery and chemotherapy (platinum-pemetrexed). Stratification variables were histology (epitheliod vs. non-epithelioid), PS (0-1 vs. 2), surgery (extended P/D vs. simple P/D or biopsy only), stage (I-II vs. III-IVA). Eligibility included PET staging, presence of gross residual disease after surgery, technical possibility of delivering high dose hemithoracic radiotherapy (total mean lung dose < 22 Gy). Exclusion criteria included contralateral mediastinal lymph node metastasis and intrascissural disease. This study was designed to obtain an overall survival improvement at 2 years of 25% (20% vs. 45%) in the RHR arm (power 80%, 2 sided alpha error =0.05). This abstract is part of the media programme and will be released on the day of its presentation Proffered Papers: CL 9: Proffered papers : Late breaking abstracts