P-094Neoadjuvant chemoradiotherapy or chemotherapy preoperative on outcomes of patients with locally advanced or irresecable gastric cancer(LAGC)

Introduction: The only curative treatment for gastric cancer remains surgery neoadjuvant chemoradiotherapy (NACRT) has shown decrease of staging and improve survival. La NACRT has been studied in esophagus cancer and gastroesophageal junction cancer but these trials did not include advanced gastric disease. The aim of our study was to investigate the role of Chemoradiotherapy (CTR) and chemotherapy (CT) in the treatment of LAGC. Methods: We retrospectively reviewed the medical records of 102 patients who were treated between December 2010 and January 2014, with preoperatory CRT or chemotherapy preoperative (CT).The group of patients treated with CT received oxaliplatin, epirubicin and fluoropyrimidine, the other group received 2 chemotherapy cycles with platinum/5FU prior to the start of CRT (treatment adapted for the delay start of RT) after receiving CTR based on platinum/5FU followed by surgery. Evaluating parameters of resectability, pathological response complete, prognostic with a 3-year follow-up. Results: A total 102 patients were analyzed, 56 men and 46 women with median age 54 years, all patients had gastric adenocarcinoma, 80(78,4%) with diffuse 22(21.6%) intestinal histology, however 83 patients (81.3%) had component of signet ring cells.Of the 102 patients, 37(36.2%) received chemotherapy and 65 (63.8%) received CRT preoperative. R0 radical surgery was possible in 41 patients of which 27% (10/37) were in the group of CT and 47% (31/65) CRT group. Radiological progression was documented in 8 (21.6%)patients with CT and 11 (16.9%) with CRT. 7 patients were considered inoperable and 17 were unresectable at the end of the preoperative treatment. The carcinomatosis was documented during the surgery by laparoscopy initial in 11 and 12 patients in the CT or CRT group respectively. 10 patients developed complications gastrointestinal and hematologic to the treatment with CT and 23 patients with CRT, which 4 patients in CRT needed reoperation post surgery. Any patient in the chemotherapy group reached complete pathologic response while of the CRT group achieved 5 complete pathological responses. Medium-3 years follow-up survival rate was 11% in the group treated with CT and 23% with CRT. Conclusion: Our revision showed a high rate of pathologic response in patients with LAGC that received CRT preoperative followed by gastrectomy. Patients who underwent concomitant treatment with CRT showed superior outcomes in survival when compared to those undergo chemotherapy. On the other hand R0 resection has been reported to be a predictive factor for survival in this study were found more patients with resectable tumor after CRT preoperative. Another characteristic of our series is the high number of patients with signet ring cells component which is associated with the prognosis Although our study has limitations because is small retrospective study that did not include selection of patients with an initial laparoscopic staging to consider characteristics of the peritoneal lavage and initial carcinomatosis, however in patients with bulky metastatic lymph nodes or irresectability could be an option, but studies homogeneous and better designed are needed.