The present invention provides methods for improving treatment effect in a patient suffering from gastric cancer, in particular, adenocarcinoma of the stomach or gastro-esophageal junction ("GEJ"), by treatment with bevacizumab (Avastin®) in combination with a chemotherapy regimen by determining the expression level of neuropilin relative to a control level determined in patients suffering from gastric cancer, in particular, adenocarcinoma of the stomach or gastro-esophageal junction ("GEJ"). The improved treatment effect may be improved overall survival or improved progression free survival. The present invention further provides for methods for assessing the sensitivity or responsiveness of a patient to bevacizumab (Avastin®) in combination with a chemotherapy regimen, by determining the expression level of neuropilin relative to a control level determined in patients suffering from gastric cancer, in particular, adenocarcinoma of the stomach or gastro-esophageal junction ("GEJ").
