Objective methods for detecting and diagnosing intestinal-type gastric cancers are described herein. Also described is method for predicting the presence or absence of
lymph node metastasis (i.e., identifying the metastatic
phenotype). In one embodiment, the diagnostic method involves the scoring of
gene expression profiles that discriminate between
lymph node positive tumors and
lymph node negative tumors. The predictive
score calculated acts as diagnostic indicator that can objectively indicate whether a sample tissue has the metastatic
phenotype. The present invention further provides methods of diagnosing intestinal-type gastric
cancer in a subject, methods of screening for therapeutic agents useful in the treatment of intestinal-type gastric
cancer, methods of treating intestinal-type gastric
cancer and method of vaccinating a subject against intestinal-type gastric cancer.