The present application provides methods for the treatment of cancer, comprising administering substantially non-anticoagulant 2-O, 3-O desulfated heparin to patients suffering from cancer that is, or can become resistant to, cancer treatment, such as chemotherapy, targeted cancer therapy, or radiation therapy. The compositions can be administered to sensitize, or to reverse resistance to, cancer treatment, and can be administered alone or in combination with cancer treatment to subjects with solid tumors including, but not limited to, pancreatic, breast, renal, colorectal, gastric, or esophageal cancer, and subjects with hematologic malignancies, including but not limited to leukemia and lymphoma.
