Surgical treatment of gastric cancer: Oncologic outcome of neoadjuvant treatment in the German multicenter observational study II.

Abstract

139 Background: Neoadjuvant chemotherapy is broadly established in European centers when treating locally advanced gastric cancer. However, there still remain questions as to the benefit of this extended form of treatment in regards to tumor location and stage. Methods: Data obtained in the ongoing prospective, multicenter observational study (German Gastric Cancer Study II) on quality assurance in surgical therapy of gastric cancer containing a total of 2897 patients treated from 01/01/2007 through 31/12/2009 in 145 surgical departments to evaluate. Results: Overall, 506 patients (18.4%) received neoadjuvant treatment in regards to all tumor stages. Of the 530 patients with adenocarcinoma of the gastroesophageal junction (GEJ) 34.5% (n=183) received chemotherapy. In detail, 30.1% (n=873) of the patients were found to be in stage I. In regards to the mean time of survival for advanced stages (III/IV 6th editiion) a survival benefit for patients receiving neoadjuvant treatment (n=356) of 12.0 months was demonstrated versus 10.0 months (p=0.048) for patients not being treated neoadjuvantly. Improved survival through neoadjuvant treatment could not be demonstrated in GEJ tumors, both, comparing different types of GEJ and matching cancer of the GEJ and distal gastric cancer. Overall survival in GEJ tumors is significantly lower (25 months) compared to the overall survival in distal gastric cancers (38 months). In addition, 5-year survival rate of GEJ tumor patients (33.1 %) was distinctly lower than for patients with distal gastric cancer (41.4 %). Conclusions: The results reflect the difficulties of applying currently available study results to daily clinical practice. In order to achieve improved treatment results, requirements in diagnostics, oncological and surgical settings are paramount. Future data of this observational study can provide additional insight for this process.