P-326 Chemoradiotherapy treatment in gastroesophageal junction tumors

Abstract

The esophagogastric junction (EGJ) and gastric cardia, represent anatomical sites with a remarkably high and rapidly rising incidence of adenocarcinoma. Although surgery is the primary curative modality for EGJ tumors, long-term outcomes are not satisfactory with resection alone, even if microscopically complete. This poor long-term outcome has prompted an evaluation of neoadjuvant (preoperative) and adjuvant (postoperative) combined modality therapy. The best form of multimodality therapy is not established. The clinical histories of patients with locally advanced gastroesophageal junction cancer from the Oncology Section of the Italian Hospital in Buenos Aires from 2014 to 2019 were analyzed retrospectively. The clinical characteristics of the patients and their treatments were evaluated. For the analysis of global survival and progression-free survival, the Kaplan-Meier method was used. 105 patients were diagnosed with EGJ, 63 patients underwent concomitant neoadjuvant chemotherapy and radiotherapy, with a median of 62 years ranging from 20 to 84 years, 85% (51) men, 91% (55) ps 0-1, 65% (39) smoking, 17% (10) had Barret's esophagus. The diagnosis was made with high videoendoscopy with biopsy in 100%, staging with PET/CT in 77% (46), 73% (44) had positive nodes and 48% (29) had siewert II location. 92% (55) of the tumors corresponded to adenocarcinomas and 35% (21) were tested for her2 of which 24% (5) were positive. The radiotherapy dose was 180 Gy with 41 Gy per session. 98% (59) completed radiotherapy, of which 96% did 3D radiotherapy and 4% (2) IMRT. 92% (55) received carboplatin 2 AUC and paclitaxel weekly. 58% (35) had toxicity, and of these, 51% (18) had hematological toxicity grade 1-2. The objective response rate was 78% (47), evaluated by pneumo-tomography, and 10% (6) patients progressed intra-treatment. Surgical compliance was 72% (43), 67% (29) underwent esophagectomy. 14% (6) had a complete pathological response in the post operative part, it was a subrogant of OS with HR 0.4 (CI 0.16 to 0.96) p = 0.041. 22% (13) patients performed adjuvant, the majority of these with capecitabine, there were no significant differences in DFS or OS with the addition of adjuvant treatment. With a mean follow-up of 25 months, 19% (8) of the operated patients relapsed, with 50% systemic relapses. All relapsed patients received FOLFOX. 32% (16) died during follow-up with an OS of 18 months and a DFS of 16 months. Neutrophil/lymphocyte ratio greater than 3 at diagnosis was 45% (27) and a statistically significant association with mortality was observed (p=0,034). Good surgical compliance was observed, with acceptable toxicity, and the objective response rate was high. Adjuvant treatment offered no benefit in OS or DFS. The complete pathological response was a surrogate for survival. Neutrophil/lymphocyte ratio at diagnosis was associated with mortality. The results in our center were similar to those of the CROSS study.