Abstract
Chemotherapy can achieve approximately 50% rates of response, survival advantage or both for every type of gastrointestinal tumor. Findings favor adjuvant therapy for all high-risk tumors. Test-worthy candidate regimens possibly increase safety and efficacy, and challenge traditional choices of treatment for patients with either unresectable or metastatic disease. They create many new options and an unprecedented order of complexity. Treatments remain to be compared and integrated. Efforts to assess the impact of patient characteristics, cost and safety are preliminary at best, and critical to rational usage. There are as yet no perfect regimens, only a series of options supported by incomplete but clearly more promising findings than heretofore. These include: biochemical modulation for gastric and colonic cancer; chemotherapy as a radiotherapy adjuvant for esophageal, rectal, anal, and pancreatic cancer; and immunotherapy for gastric and colorectal cancer. Selective application of endocrine therapy, circadian time schedules or regional therapy may augment safety and quality of life. While response rates have probably improved, their exact frequency, quality and effect on survival are incompletely characterized. Investigations, offer the best way to deal with the options and speed progress, in the context of building upon apparent best therapies.