The present invention relates to a polysaccharide comprising, optionally substituted, monosaccharide units linked via alpha-glycosidic bonds for use in preventing metastasis formation and/or relapse by administration to a body cavity of a subject afflicted with cancer. The present invention further relates to a method for preventing metastasis formation in a subject afflicted with cancer, comprising administering said composition to a body cavity of said subject, and thereby preventing metastasis formation in said subject. The present invention also relates to a composition and to a kit comprising a polysaccharide and a pharmaceutically acceptable means of solubilizing the same and to a device comprising a polysaccharide and means for administering the same.
