New approaches to the treatment of gastro-intestinal cancer.

A number of new cytotoxic agents are currently being assessed for the treatment of gastro-intestinal cancers. Colorectal cancer has been successfully treated with several direct thymidylate synthase inhibitors, oral 5-fluorouracil analogues, irinotecan, and oxaliplatin, alone and in combination regimens. Upper gastro-intestinal malignancies are also proving responsive to combinations including irinotecan and the taxanes. Pancreatic cancer, while remaining relatively chemoresistant, is proving treatable with the new direct thymidylate synthase inhibitors, docetaxel, and gemcitabine, improvements in quality of life being an important outcome. New strategies of treatment delivery are also proving beneficial. Neo-adjuvant chemotherapy is well tolerated for the treatment of gastric cancer and results in tumour downstaging. Randomized trials will show whether this translates into a survival advantage. Combination chemoradiation for oesophageal, pancreatic, and rectal cancers also appears to be an effective strategy. Biological therapies including hormonal manipulation, immunotherapy, angiogenesis inhibition, and gene-directed therapies are the subjects of intensive research at present, with many approaches being applied in early clinical trials. These have demonstrated the tolerability of many of these treatments with evidence for activity in some cases.