The present invention relates to: a pharmaceutical composition for inhibiting the proliferation or metastasis of invasive pancreatic cancer in a subject, which comprises an anti-cancer molecular targeting drug and a pharmaceutically acceptable carrier, wherein the anti-cancer molecular targeting drug is produced by binding a toxin or a cytotoxic agent to an antibody capable of binding immunologically specifically to a cell surface folate receptor (FR) ß protein of an FRß (+) macrophage that exists around a pancreatic cancer cell at an invasive front； and a diagnostic agent and a kit, both of which can be used for determining the degree of malignancy of pancreatic cancer or the occurrence of invasive pancreatic cancer, and both of which are characterized in that it is determined that a cancer tissue is invasive and metastatic when a FRß (+) macrophage is distributed around a pancreatic cancer cell at an invasive front.
