2236 Survival outcomes in patients with locally advanced esophageal squamouscell carcinoma treated with nab-paclitaxel and cisplatin as neoadjuvant chemotherapy

Abstracts Diffusion-weighted MRI Protocol and Imaging Analysis Diffusion-weighted MRI (DWI) was performed prior to CRT, at the end of 20Gy using a 1.5-T body scanner equipped with a phased array body coil with following sequences: sensitivity-encoded single-shot echo-planar imaging, short-tau inversion recovery for fat suppression, TR 7800ms and TE 65 ms, b = 0 and 1000 s/mm2, 4 mm slice thickness, 1 mm gap. Apparent diffusion coefficient (ADC) values were measured on a maximum slice of the tumor by sampling method of five random round-shaped ROIs and the median ADC was adopted. ADC values and increased ADC ratio to pretreatment (DADC) were assessed. Results: ADCs and DADCs at the end of 20 Gy were significantly higher in responders than in nonresponders (ADC 1.13 vs. 0.93, P < 0.01 and DADC 35.4 vs. 1.5%, P < 0.01). 20Gy-ADC predicted the responders with the sensitivity, positive predictive value and accuracy of 79%, 73% and 74% by the cut-off ADC value of 1.00×10−3 mm2/s, and also 20Gy-DADC with those of 71%, 100% and 85%, respectively by the cut-off DADC value of 15%. Patients with 20Gy-ADC <1.0 and 20Gy-DADC 15% had significantly poor prognosis (P < 0.01). Conclusions: An early increase of ADC correlated with the final response to CRT and predicted the patient prognosis of eSCC. Non-invasive DWI may be a useful modality in selecting appropriate treatment for the patients of eSCC. No conflict of interest. 2234 POSTER Retrospective analysis of hyperthermia intraperitoneal chemotherapy for gastric cancer with peritoneal dissemination M. Yuan1 , Z. Wang2 , Y. Yang1 , W. Lv1 , F. Lu3 , H. Zhong1 . 1 Zhejiang cancer hospital, Department of Chemotherapy, Hangzhou, China; 2 Zhejiang cancer hospital, Department of Pharmacy, Hangzhou, China; 3 Zhejiang cancer hospital, Department of Radiology, Hangzhou, China Background: Peritoneal dissemination is a poor prognostic factor in patients with gastric cancer. In this study we evaluated the efficacy and safety of hyperthermia intraperitoneal chemotherapy (HIPC) in advanced gastric cancer with peritoneal dissemination through retrospective analysis. Material and Methods: 54 gastric cancer patients with a positive cytology of ascites were included in this study. 23 patients used systemic chemotherapy combined with HIPC (HIPC+ group) and 31 accepted systematic chemotherapy only (HIPC− group). Results: Patients were divided into 4 categories according to the changes of ascites, including disappear, reduce, similar, increase. The (disappear + reduce)% in the HIPC+ group was 82.60%, better than the HIPC− group, which was 54.80%, p = 0.043. The (disappear + reduce + similar)% was 95.7% in the HIPC+ group and 74.2% in the HIPC− group, p = 0.062. In 33 patients with complete survival data, including 12 in the HIPC + group and 21 in the HIPC− group, the median progression-free-survival (PFS) was 169 days,127 days; and the overall survival (OS) was 325 days, 300 days, respectively. In patients with ascites disappear + reduce+ similar, the OS seems better than patients with ascites increase, but no significant difference, p = 0.08. Further analysis showed that patients with the disease controlled (CR+PR+SD), may have better OS than patients with the disease PD, p < 0.01. The toxicities were totally tolerated in both groups. Conclusion: HIPC for advanced gastric cancer with peritoneal dissemination gave encouraging results, but large multicenter prospective randomized controlled studies are needed to conform it. No conflict of interest. 2235 POSTER Adrenocortical carcinoma (ACC), what is the optimum management? A report of single center experience S. Atallah1 , M. Thomas2 , H. Al-Assaf1 , S. El-Sayed1 . 1 Ottawa Hospital, University of Ottawa, Radiation Oncology, Ottawa, Canada; 2 Ottawa Hospital, General Campus, Radiation Oncology, Ottawa, Canada Background: ACC is a rare disease and one of the most aggressive and fatal endocrine neoplasms. Surgical resection is an important therapeutic option for both early and advanced disease, however; with frequent local and distant failures and poor survival. Mitotane is the standard adjuvant modality in many centers, but so far based on retrospective evidence. The role of adjuvant radiotherapy is ill defined and needs more research efforts. Objective: The aim of this study is to review the demographic characteristics and outcome by treatment modality of ACC patients (pts.) treated in one Cancer Center over 40 years Material and Methods: A retrospective chart review for ACC pts. treated in one Canadian Cancer Centre between January1974 and December 2013. Data were extracted from electronic and physical charts including:

S411 demographic data, date of diagnosis, type and date of diagnostic imaging, type and date of biopsy, date of referral to Cancer Center, service first seen by, and presenting symptoms. Also, tumour laterality, size, histopathology, staging, date and type of surgery, type of adjuvant treatment, date and type of failure, vital status, dates of death and date of last follow up. Statistical Analysis:Overall survival was calculated from date of diagnosis. Survival curve was created using Kaplan Meier analysis. Data presented in percentage, median, range, and mean. Charts were created to present patient demographic data. Results: Out of 81 pts. identified with adrenal tumors, 39 had confirmed diagnosis of ACC. There is a rising trend in the number of referred patients the last 10 years. Median age for female and male were 39 and 64 year respectively (range: 19; 71 and 35;82). The most common presenting symptom was abdominal pain (15 pts. 39%) and Cushing syndrome (8pts. 21%). Eight pts. (21%) had incidental adrenal mass found during investigation for other reason. Most pts. were seen by surgeons initially. When referred to Cancer Centre they are mainly referred to medical Oncologists. Out of the 32 pts. who had surgeries, 16 pt. had adjuvant systemic treatment including mitotane or concurrent chemoradiation, only 6 pts. (15%) had adjuvant radiation therapy (RT). Of those 6 pt., 3 had adjuvant concurrent chemoradiation with Cisplatin and 3 still alive (2 of them alive with distant failure). At median follow up period of 3.8 years, 28 pts. died (71%), 10 were alive (25%) and one unknown. Of the 26 pt. with known failure, 22 had failures data, 2 of them were local failure and the rest were distant. Conclusion: ACC is a rare disease with poor prognosis. The current data is insufficient to make informed treatment recommendations. We recommend starting a Prospective National Database to create the opportunity for further research into the best treatment approach for these tumors. No conflict of interest.

2236 POSTER Survival outcomes in patients with locally advanced esophageal squamouscell carcinoma treated with nab-paclitaxel and cisplatin as neoadjuvant chemotherapy F. Yun1 , Y. Jiang-2 , Q. Chen2 , X. Zhou2 , Z. Huang1 , W. Mao2 . 1 Zhejiang Cancer Hospital-Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology and Cancer Research Institute, chemotherapy, Hangzhou City, China; 2 Zhejiang Cancer Hospital, Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology and Cancer Research Institute, Surgery department, Hangzhou City, China Background: The combination of nab-paclitaxel and cisplatin as preoperative treatment for esophageal squamous cell carcinoma (ESCC) has not been investigated. We carried out a phase II feasibility and efficiency study of preoperative chemotherapy with nab-paclitaxel and cisplatin for locally advanced ESCC. Methods: Between January 2011 and October 2012, 35 patients, from stage IIA to IIIC, performance status 0−1, with31 male and4 females, were included in the study. All pts received nab-paclitaxel (100 mg/m2 , d1, d8, d22 and d29) and cisplatin (75 mg/m2 , d1 and d22) as neoadjuvant chemotherapy, followed by esophagectomy. Two cycles of adjuvant chemotherapy with same regimen was given in 4−6 weeks after the resection. Results: Overall response rate (ORR) evaluation was performed at the end of cycle 2. Out of the 35 enrolled patients, 30 were males and 4 females;Three (8.6%), 5(14.3%),10 (28.6%), 8 (22.9%) and 9 (25.7%) patients were in IIA, IIB, IIIA, IIIB, IIIC, respectively. 5 patients did not going to surgery, as 2 patients with progressive disease and another 3 patients refused. 30/35patients went to surgery (85.7%) and all had R0 resection (100%). Pathological complete response (pCR) was achieved in 4 patients (13.3%). Near pCR (microfoci of tumor cells on the primary tumor without lymph nodal metastases) in 2 patients (6.7%). Downstaging was observed in 19 of 30 patients (63.3%). 24/30 (80.0%) patientsreceived adjuvant chemotherapy; among, 7 patients (23.3%) received adjuvant chemoradiotherapy. Only 1 (3.3%) patient appeared surgical complicationwithanastomotic leaks. The most frequent G3-G4 toxicity included neutropenia (11.4%), anemia (8.6%), thrombocytopenia (5.7%), nausea/vomiting (14.3%), neutropenia fever (8.6%), asthenia (20.0%). With median follow up of 27.1months, the 16/30 patients (50.4%) still alive, and a median disease-free time (DFS) of 22.5 months (95% CI 14.2–29.8) were observed. Median overall survival times and DFS of downstaging patients were significantly longer than non-down-staging patients (Hazard Ratio 0.30, 95% CI: 0.074–0.75 and Hazard Ratio 0.27, 95% CI: 0.071–0.59, respectively) (P = 0.0158 and P = 0.0037, respectively). Conclusions: Weekly nab-paclitaxel and cisplatin is effective as a neoadjuvant chemotherapy for local advanced ESCC, and its adverse

S412 effects are tolerable, down-staging patients have favorable outcome than non-down-staging patients. No conflict of interest. 2237 POSTER Chemotherapy for patients with locally advanced pancreatic cancer (LAPC) with additional chemo-radiotherapy (CRT) for patients with borderline resectable tumours J.K. Bjerregaard1 , M. Ladekarl2 , M.B. Mortensen3 , A.L. Fromm4 , P. Pfeiffer1 . 1 Odense University Hospital, Department of Oncology, Odense, Denmark; 2 Aarhus University Hospital, Department of Oncology, Aarhus, Denmark; 3 Odense University Hospital, Department of Surgery, Odense, Denmark; 4 Herlev University Hospital, Department of Oncology, Herlev, Denmark Background: The optimal treatment algorithm for patients with locally advanced pancreatic cancer (LAPC) is controversial. Multimodality treatment including combination chemotherapy and/or chemo-radiotherapy (CRT) might downstage tumors to allow a potential radical resection. In this ongoing phase II study we examined the feasibility of FOLFIRINOX with or without CRT followed by surgery if successfully down-staged (NCT01397019). Material and Methods: Patients in performance Status 0−1 and with non-resectable stage II/III pancreatic cancer were offered FOLFIRINOX (oxaliplatin 85 mg/m2 , irinotecan 180 mg/m2 , leucovorin 400 mg/m2 , 5FU 400 mg/m2 + 2400 mg/m2 ) every 14 days. Every 4th series the patient would be re-evaluated and offered CRT (50.4 Gy/27F & capecitabine) if deemed potentially resectabel. Following this the patient would be offered resection or continue FOLFIRINOX. Results: Between August 2012 and present, 42 eligible patients have been recruited with a median observation time of 13.5 months. Median age was 65(range 38−75) years, with 47%/53% stage II/III distribution. Median CA19-9 was 299 (range 2–13,432). Two-hundred-seventy-four courses of FOLFIRINOX have been given, with a median of 6.5 per patient, with a median of 2 without dose modifications. Twenty-one patients were treated with CRT. Twelve patients were resected, of which 7 received CRT. Median survival for all patients was 15.6 months (11-NR) with a 1-year survival of 70% (49−84). For patients not resected the median survival was 12.8 months (9−16) for resected patients the median survival has not yet been reached. The FOLFIRINOX was associated with adverse events similar to what is expected in metastatic patients. Conclusions: FOLFIRINOX with or without CRT in patients with LAPC shows promising efficacy with acceptable toxicity, however dose reductions are often needed. No conflict of interest. 2238 POSTER Treatment of localized anorectal gastrointestinal stromal tumors with preoperative imatinib mesylate therapy W. Wang1 , S. Luo2 , W. Chen2 , L. Kang2 , Y. Deng1 . 1 The 6th Affiliated GastrointestinalHospital of Sun Yat-sen University, Clinical Oncology, Guangzhou, China; 2 The 6th Affiliated GastrointestinalHospital of Sun Yat-sen University, Colorectal Surgery, Guangzhou, China Purpose: The study aimed to explore the surgical outcome and response of Imatinib mesylate (IM) as preoperative treatment for anorectal gastrointestinal stromal tumors (GISTs). Methods: We conducted a retrospective analysis of anorectal GIST patients treated between January 2007 and December 2014 in our hospital. For purpose of analyses, the patients have been divided in two groups. Because of tumor size and location, IM was given preoperatively in Group A, at a dose of 400 mg/d. In group B, patients directly underwent surgeries because of small tumor size or lack of availability. Results: Thirty-two patients (22 male and 10 female) with anorectal GISTs were identified. Fifteen patients received IM before surgery for a median duration of 4 months (2−12 months) (Group A), while 17 patients accepted surgeries directly (Group B) because of small tumor size or lack of IM availability. The primary tumor size in Group A was significantly larger than Group B (p < 0.001). Median tumor size in Group A decreased from 7.0cm (3.8–12.5 cm) to 5.0cm (1.0−8.2 cm) (p = 0.001) after IM treatment. Histopathological analysis revealed a notable decrease in mitotic count (2.5±0.8 vs. 1.3±0.9, p = 0.034). Six patients (6/12, 50%) lost CD117 expression and 2 patients (2/12, 16.7%) lost CD34expression. Thirteen patients had a partial response and 2 had stable disease. Twelve out of 15 patients in Group A accepted surgeries finally. For the cases of tumor size 5 cm in the two groups, there was no significant difference in sphincter preserved rate, R0 resection rate, operative time, or postoperative

Abstracts complications. Up to last follow-up in April 2015, local recurrence occurred in 3 patients in Group A. One patient in Group B had distant metastasis. The median DFS and mean OS were not reached in both groups. Group A (n = 15) Duration of IM therapy, median (months) Median tumor size (cm) Before IM therapy After IM therapy Median anal verge distance (cm) Before IM therapy After IM therapy Mitotic count (per 50 HPFs) Before IM therapy After IM therapy CD117+ Before IM therapy After IM therapy (n = 12) CD34+ Before IM therapy After IM therapy [S1] (n = 12) Efficacy of IM therapy PR CR SD PD

p value

4.0 (2.0–12.0) 0.001 7.0 (3.8–12.5) 5.0 (1−8.2) 0.831 2.9 (0−5.5) 3 (0−5.5) 0.034 2.5±0.8 1.3±0.9 0.003 15/15 6/12 0.188 15/15 10/12 13 0 2 0

Conclusions: Preoperative IM therapy leads decreasing in tumor size and CD117 expression. Preoperative IM therapy is a considerable strategy for increase the opportunity of anal sphincter preservation surgeries for large anorectal GISTs. No conflict of interest. 2239 POSTER Long-term results of preoperative chemoradiation in clinically resectable gastroesophageal cancer: A single institution experience M. Vosmik1 , J. Laco2 , I. Sirak1 , M. Lesko3 , R. Repak4 , J. Dvorak5 , B. Melichar6 , P. Lochman3 , M. Hodek1 , J. Petera1 . 1 University Hospital Hradec Kralove, Department of Oncology and Radiotherapy, Hradec Kralove, Czech Republic; 2 University Hospital Hradec Kralove, The Fingerland Institute of Pathology, Hradec Kralove, Czech Republic; 3 University Hospital Hradec Kralove, Department of Surgery, Hradec Kralove, Czech Republic; 4 University Hospital Hradec Kralove, 2nd Department of Internal Medicine − Gastroenterology, Hradec Kralove, Czech Republic; 5 Thomayer Teaching Hospital, Department of Oncology, Prague, Czech Republic; 6 University Hospital Olomouc, Department of Oncology, Olomouc, Czech Republic Background: The role of preoperative chemoradiotherapy (CRT) in the treatment of adenocarcinomas (AC) of distal esophagus, gastroesophageal junction (GEJ) and stomach is still not clear. The aim of presented study was to evaluate the long-term results of this approach in patients (pts) treated at our institution. Material and Methods: We retrospectively reviewed the results of preoperative CRT in pts with locally/regionally advanced, but clinically resectable gastroesophageal AC treated with curative intent and prescribed dose of radiotherapy (RT) 40 Gy. The therapeutic response was evaluated retrospectively as a percentage of residual tumor cells (RTC: 0%; 1%; 2−10%; 11−50%; 51–100%). Overall survival (OS) and diseasefree survival (DFS) probability were calculated using the Kaplan–Meier method. The influence of histological subtype and grade, pretreatment and pathological T-stage and N-stage, angioinvasion, perineural invasion and therapeutic response of CRT on OS were analyzed by logrank test, Cox regresion univariate and multivariate analysis. Results: A total of 108 pts (20 females, 88 males, age 28−80 years, median 62.5 years) underwent preoperative CRT for AC of distal esophagus (24 pts), GEJ (39 pts) or stomach (45 pts) between January 2000 and March 2014. The prescribed dose of RT was 40–50.4 Gy, median 45 Gy. The concurrent chemotherapy was 5-FU (all 108 pts) +/− cDDP (80 pts) +/− taxanes (7 pts). R0 resection was possible in 80 pts (74%), in 3 pts the resection was R1. The tumor was unresectable in 23 pts (mostly for peritoneal dissemination). Two pts did not undergo the surgery. Seventynine R0 resected samples were available for the retrospective pathological evaluation. The complete response (0% RTC) was in 20 cases (19%), response 1% RTC was in 24 cases (22%), 1−10% in 16 cases (15%), 11−50% in 8 cases (7%) and no response (51–100%) was in 11 cases (10%). The median follow-up of surviving patients was 50.8 months (7– 165 months). 3-y and 5-y OS was 36.2% and 25.3%, resp., and 3-y and 5-y DFS was 37.2% and 31.4%, resp. Pretreatment T-stage, pathological N-stage, histological subtype, angioinvasion and perineural invasion were