ESTRO 37 Abstract book

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ESTRO 37

portions/ abdominal portions in 11/50/9/2, respectively. Tumor invasion confined to the mucosa, submucosa and muscularis propria was 13, 52 and 7, respectively. Three- year OS and DFS were 81.7% and 58.3%, respectively. Three-year OS were 89.7% and 78.7% in the patients with and without ENI, respectively. And 3-year/5-year DFS in patients with and without ENI were 75.0%/51.9% and 37.3%/31.8%, respectively. There was no significant difference for OS and DFS (p=0.68 and p=0.23, respectively). A total of 17 patients (23.6%) relapsed: 6 (8.3%) developed local, 11 (13.9%) developed regional (with/without ENI, 2/9; out/in-field, 10/1), 1 developed loco-regional and 1 developed lung metastasis. On univariate analysis for OS and DFS, ENI was not significant factor (p=0.69 and p=0.22, respectively), and Age, PS and treatment modalities (CRT vs RT alone) were significant factors for OS. On multivariate analysis, higher age (hazard ratio [HR] 1.06; 95% confident interval (CI) = 1.01-1.12; p=0.019,), and worse PS (HR 1.81; 95% CI = 1.04-2.93; p=0.038) were independently associated with worse OS. Conclusion This analysis suggested that ENI was not necessary for patients treated with RT for stage I esophageal cancer. A further prospective study to evaluate the role of ENI in stage I esophageal cancer is warranted. EP-1436 Impact of Complete Pathological Response to Neoadjuvant Chemoradiotherapy in Esophageal Cancer T. Soror 1,2 , G. Kho 2 , K. Zhao 3 , M. Ismail 4 , H. Badakhsh 2 1 National Cancer Institute, Radiation Oncology, Cairo, Egypt 2 Ernst von Bergmann Medical Center- Academic Teaching Hospital of Humboldt University Berlin Charité- Germany, Department of Clinical Radiation Oncology, Berlin, Germany 3 Fudan University Cancer Center, Radiation Oncology, - Shanghai-, China 4 Charité University Hospital, Thoracic surgery, Berlin, Germany Purpose or Objective Neoadjuvant chemoradiotherapy (CRT) followed by surgery improves the treatment outcome in patients with esophageal cancer, the pathological response is an important predictor in such patients. This work represents a single-center analysis. Material and Methods All patients treated with neoadjuvant chemoradiotherapy (CRT) followed by surgery between January 2002 and December 2013 were reviewed. The patients were categorized into two groups according to the pathological response following CRT; complete pathological response (pCR group) and non-complete pathological response (non-pCR group). Statistical significance level was established at p<0.05 and survival curves were estimated using the Kaplan-Meier method. Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 22.0. (Armonk, NY: IBM Corp.).

Results Fifty-six patients with invasive cancer, 23 patients (41.1%) achieved pCR and 33 patients had non-pCR (58.9%) following preoperative CRT. The average age was 62 years (±9.1), and most patients were males (83.9%). Histological types included squamous cell carcinoma (75%) and adenocarcinoma (25%). The total radiation dose was 45 Gy in 76.8% of the patients and 50.4 Gy in 23.2%. The median overall survival (OS) of the entire group was 3.5 years ±1.2, and the 5-year OS rate was 38%, while the median disease-free survival (DFS) was 2.1 years ±0.4 and the 5-year DFS rate was 33%. The patients who achieved pCR had significantly higher 5-year OS and 5-year DFS rates; 47% and 48% compared to 27% and 21% for the non- pCR patients respectively (P=0.4, 0.4). The median time of local recurrence was 11.01 months ±3.1 in pCR group and 9.4 months ±1.1 in non-pCR group (P=0.1), while the median time of distant metastases in pCR group was 12.6 months ±5.5 and 12.1 months ±1.9 in non-pCR group (P=0.6).