Advances in the management of gastrointestinal malignancies.

Although progress in treating gastrointestinal (GI) malignancies has been slow, several new approaches have resulted in increased response rates and, in some cases, improved survival. A greater understanding of the etiology of GI cancers makes possible the prevention of many of these tumors. New diagnostic tools, including endoscopic ultrasound, the CA19-9 radioimmunoassay, and the carcinoembryonic antigen assay, have improved clinicians' ability to detect early-stage and recurrent disease. Efforts to enhance response to fluorouracil (5-FU) in the treatment of colorectal cancer by the addition of various immunologic or biochemical modulators have yielded encouraging results. Combinations of 5-FU with levamisole, interferon alfa, leucovorin, methotrexate, or N-(phosphonacetyl)-L-aspartate have resulted in significant increases in response rates and, in the case of 5-FU/levamisole, increased survival. Promising results have also been obtained in the treatment of pancreatic cancer with a combination regimen of monoclonal antibodies (MoAbs) plus chemotherapy (5-FU/doxorubicin/mitomycin) and in the treatment of hepatocellular cancer with an antiferritin MoAb/radioisotope conjugate. Finally, the addition of interferon alfa to 5-FU has produced improved response rates in preliminary trials in patients with esophageal cancer. Other strategies, such as attempts to enhance MoAb activity in the treatment of pancreatic cancer, may prove productive as well and are currently being explored in laboratory and clinical studies.