[Gastric cancer and adenocarcinoma of the esophagogastric junction: principles of neoadjuvant therapy].

According to the current European and German S3 guidelines, neoadjuvant chemotherapy is now an integral part of the treatment of locally advanced gastric cancer and adenocarcinoma of the esophagogastric junction. Neoadjuvant therapy seeks to achieve downsizing of the primary tumor, lowering of the T and N categories and eradication of micrometastases. As the indications for neoadjuvant treatment are based on pretherapeutic information alone, a sophisticated clinical staging plays a central role. Despite all progress made in the field of diagnostic work-up, clinical staging often fails. Despite this fact, controlled randomized trials showed that neoadjuvant chemotherapy enhances the rate of curative (R0) resections and reduces the likelihood of systemic relapse. Overall, survival can be improved by neoadjuvant chemotherapy. The current research is focused on the molecular prediction of response and early response monitoring with functional imaging. New targeted drugs are being integrated into the peri-operative treatment.