Induction Chemotherapy Followed by Chemoradiotherapy in Locally Advanced Esophagogastric Adenocarcinoma. Has the Location of the Primary Tumor Any Influence on Patients' Outcome? a Retrospective Analysis

ABSTRACT Aim: Multimodal therapy is the standard of care in locally advanced esophagogastric adenocarcinoma. However, most trials include both, gastric (GC) and gastroesophageal junction (GEJ) cancers. We aimed to rule out whether patients (pts) with either locally advanced GEJ (group A) or GC (group B) have different outcomes when treated with a neoadjuvant approach based on induction chemotherapy (ICT), chemoradiotherapy (CRT) and surgery. Methods: EUS-T2-4 and/or N+ M0 GEJ or GC adenocarcinoma patients were scheduled to receive preoperative therapy (3-4 cycles of chemotherapy followed by concurrent CRT). Surgery was scheduled 4 to 6 weeks after the end of CRT. Pathological response was graded according to the Becker criteria. Patterns of recurrence, progression-free survival (PFS) and overall survival (OS) were also evaluated. Results: From november 2004 to July 2013, 87 pts (27 in group A, 60 in group B) met the specified criteria. Pts characteristics were; Group A; M/F; 23/4; EUS-T3 52%, T4 40,7%, N+ 95%, median age 56 (31-81); Diffuse/Intestinal 55%/44%. Group B; M/F; 42/18; EUS-T3 40%, T4 56%, N+ 95%; median age 60.5 (36-76); Diffuse/Intestinal 57%/42%. Seventy-four pts underwent surgery (group A/ B; 92.6%/82%). Pathological response (Group A/B); Grade Ia-Ib according to Becker criteria (72%/51%), pN0 (60.3%/53%). R0 resection (Group A/B); (96%/94%). Among resected pts we analysed the impact of tumor location (GC vs GEJ) on known prognostic factors such as Lauren classification and degree of pathological response regarding PFS and OS. In group A, median OS and PFS did not difer according to Lauren neither classification nor pN status. In contrast, median PFS varied according to Becker response (Ia-b: Not Reached; II-III: 13m; p = 0.02). In group B, we found differences in PFS and OS according to; a)- Lauren Classification; Intestinal GC vs Diffuse GC pts [median PFS; NR vs 13.6m; p = 0.028, median OS: NR vs 15.3m; p = 0.026]. b)pN status (-/+) [median PFS; NR vs 18m; p Conclusions: When treated with ICT followed by CRT, GEJ and GC pts have different outcomes in terms of pathological response degree, patterns of recurrence and survival times. Disclosure: All authors have declared no conflicts of interest.