Conclusions: The TaTME method, although it is a difficult and very demanding technique, seems to be extremely promising in terms of oncological outcomes and remaining functionality of anal sphincters as well as good quality of life, especially in patients in whom technical dif- ficulties are predicted. Nevertheless, it requires further researches and improvement of the competence of the surgical team. Conflict of interest: No conflict of interest. 448 CHEMOTHERAPY INDUCED CARDIOTOXICITY MANIFESTED AS ARRHYTHMIA IN A PATIENT WITH SIGMOID ADENOCARCINOMA A. Chirca 1, 2 , R.V. Costea 1, 2 , M. Hasouna 1 , D.A. Pesu 1 , O.C. Rusu 1 , S. Neagu 1, 2 . 1 University Emergency Hospital Bucharest, General Surgery, Bucharest, Romania; 2 "Carol Davila" University of Meidicine and Pharmacy Bucharest, General Surgery, Bucharest, Romania Background: 5-flourouracil is widely used in the adjuvant treatment of gastrointestinal cancers, alone or in combination with other chemother- apeutic agents. During the course of chemotherapy it can induce a wide variety of cardiotoxic events. The aim of our paper is to present a rare case of 5-flourouracil induced arrhythmia in a patient with sigmoid cancer. Materials and methods: We present the case of a 60 year-old patient with medical history of hypertension that was admitted to our department for left lower quadrant abdominal pain and hematochezia lasting for 3 months. Laboratory findings including tumor markers were normal. Colonoscopy found a 2x2 cm tumor in the lower part of the sigmoid colon (biopsies were taken) confirmed by abdominal CT( computerized tomography) scan Results: The patient underwent surgery and left hemicolectomy with side to end anastomosis. The histopathological exam confirmed R0 resection, the excision of 13 lymph nodes and the diagnosis of adenocarcinoma, pT3N0M0 G2, stage IIB. Post-operative the patient developed an anasto- motic leak and a second surgery followed with the implementation of a temporary colostomy. Afterwards the patient was scheduled for chemo- therapy. After the second dose she developed clinical sings of cardiac insufficiency that were later confirmed by cardiac ultrasound. The 3 year follow-up visit showed disease free survival with the mention that the patient had a cardiac pacemaker for symptomatic bradycardia. Conclusion: We present this case to raise the awareness regarding the possibility of rare chemotherapy related cardiotoxic event such as arrhythmia and to point out the necessity of a multidisciplinary team in the management of patients with neoplasia. Conflict of interest: No conflict of interest. 450 TRANLESIONSYNTHESIS AND CLINICAL CHARACTERISTICS OF TUMOR AGGRESSION IN SPORADIC COLORECTAL CANCER G. Laporte 1 , N. Leguisamo 2 , H. Castro e Gl oria 3 , G. Montenegro 3 , D. Azambuja 4 , C.E. Escovar 5 , A. Kalil 1 , J. Saffi 3 . 1 Complexo Hospitalar Santa Casa de Porto Alegre, Surgical Oncology, Porto Alegre, RS, Brazil; 2 Institute of Cardiology/University Foundation of Cardiology-, Molecular and Cardiology Laboratory, Porto Alegre, Brazil; 3 Universidade Federal de Ci^ encias da Saúde de Porto Alegre, Laboratory of Genetic Toxicology, Porto Alegre, Brazil; 4 Complexo Hospitalar Santa Casa de Porto Alegre, Proctology, Porto Alegre, RS, Brazil; 5 Complexo Hospitalar Santa Casa de Porto Alegre, Clinical Oncology, Porto Alegre, RS, Brazil Background: Colorectal cancer (CRC) is the third most common cause of death by cancer worldwide. About 85% of those cases are sporadic colo- rectal cancer (CRC).Translesion synthesis (TLS) is a pathway of the DNA damage tolerance system. TLS bypasses DNA lesions, through specialized DNA polymerases, allowing the completion of replication of damaged genomes. This process which is error prone can lead to genomic instability, and may be linked to CRC carcinogenesis. Having in mind the link between TLS and instability, we believe that TLS may influence CRC.This study aims to evaluate gene expression of translesion synthesis (TLS) polymerases and the protein expression status of mismatch repair (MMR) in sporadic CRC cases resected during surgery and infer its influence in the main prognostic clinical and pathological features. Material and Methods: Pre-treatment tumor samples from 70 patients with sporadic CRC were assessed for 3 TLS genes (Polk, Polh and Polq) mRNA levels by qPCR. MLH1 protein expression was used to determine the MMR status (proficient or deficient) of each patient. The molecular data were analyzed in relation to clinical features and TNM staging as prognosis predictor. Results: Polk and Polh were found to be overexpressed in colorectal tu- mors incomparison to healthy intestinal tissues. The overexpression was associated with poor pathological outcomes: Polk was correlated with histology, lymphatic invasion; Polh was correlated with lymphatic inva- sion lymph node status. Moreover, Polq levels showed no significant dif- ference, but were also associated with poor pathological outcomes (age and tumour invasive depth).No associations were found between TLS polymerases expression and MMR status. Conclusion: Our findings indicate that alterations in TLS polymerases expression could play a role in the aggressiveness of CRC, since there are many associations with clinical features of tumor aggressiveness, such as lymphatic invasion and tumour invasive depth. Thus, the TLS polymerases appear to be suitable candidates as prognostic biomarkers. Nevertheless, to propose these proteins as prognostic biomarkers, it is imperative to understand the role of these proteins in CRC, if they are part of colorectal cancer’s etiology or a side effect of its development. Conflict of interest: No conflict of interest. 451 MANAGEMENT OF RECURRENT ADENOCARCINOMA OF THE RECTUM: A SINGLE CENTER EXPERIENCE A. Ben-Yaacov 1 , I. Mizrahi 2 , M. Goldenshluger 1 , E. Shacham-Shmueli 1 , D. aderka 1 , Z. Dotan 1 , D. perlson 1 , B. liberman 1 , A. bilik 1 , S. goren 1 , L. segev 1 , M. venturero 1 , A. nissan 1 . 1 Cheim Sheba Medical Center- Tel-Aviv University- Sackler School of Medicine, Department of Surgery and Surgical Oncology - Surgery C, Ramat-Gan, Israel; 2 Hadashaa Medical Center, Surgery, Jerusalem, Israel Background: The major improvement in the management of rectal cancer significantly reduced the pelvic recurrence (PR) rate. Managing PR is challenging with a high failure rate. The aim of the study is to present our multidisciplinary approach to PR of rectal cancer. Methods: This is a retrospective analysis of patients treated by a single group between 2005-2017. Pelvic recurrence was defined as recurrence of adeno- carcinoma of the rectum within the pelvis, at least six months from complete resection of the primary tumor. Patients (n¼43) were identified from a computerized database. Demographics, clinical, histological and survival data were reviewed and completed from the hospital electronic medical records. All patients were re-evaluated by colonoscopy, rigid rectoscopy, pelvic MRI and whole body cross-sectional imaging. All previous operative reports and radiation fields were reviewed by a multidisciplinary team. Results: There were 23 females and 20 males, mean age was 59.7 years. All 43 patients had prior surgery with a curative intent. Twenty patients (46.5%) were also treated by peri-operative radiotherapy and 30 patients (69.8%) had prior adjuvant chemotherapy for their primary presentation. The median time to recurrence was 28.4 months (range 6-36). Radiation therapy was performed in all non-irradiated patients. A second pelvic ra- diation course was delivered in two patients. R0 resectionwas achieved in 29 (67.4%), R1 in 11 (25.6%) and R2 in 3 pa- tients (7%). Average OR time was 5.5 hours with an estimated blood loss of 570ml. Extent of resection included rectal resection in 93.0%, small bowel resec- tion in 30.2%, colon resection in 65.1%, cystectomy with ileal conduit in 28%, sacrectomy in 7% and stoma formation in 58.1%. Mean hospital stay was 18.8 days and ICU stay was 1.1 days. Post operative complications occurred in 74.4% of which 23.3% were major (grade III-IV) complications. Post operative (90-days) mortality was 11.6%. In a median follow up of 50 months of the 38 discharged patients, 13 (34.2%) patients are alive with no evidence of disease, 13 (34.2%) alive with disease, 9 (23.7%) died of disease and 3 (7.9%) died of other causes. Median disease-free survival was 20.2 months with a median overall survival of 38.1 months. There was no difference in overall as well as disease-free survival between the R0 and the R1 patients. Conclusions: With a radical multi-disciplinary approach, salvage of pa- tients with PR is feasible. However, this combined modality therapy is Abstracts / European Journal of Surgical Oncology 45 (2019) e25ee158 e117