Adjuvant therapy for gastrointestinal cancer.

Perioperative adjuvant treatment with chemotherapy or radiation therapy has been investigated for colon, rectal, gastric, esophageal, and pancreatic cancers. To date, conclusive benefit had been shown only for colon and rectal cancers. Demonstration that adjuvant therapy can result in reductions in tumor recurrence and cancer death after surgery for large bowel cancer is a major therapeutic advancement, and current clinical trials may yield further incremental improvements. Standard recommendations for adjuvant treatment exist for patients with colorectal cancers who do not take part in these clinical studies. Several factors complicate the assessment of adjuvant therapy for gastric, esophageal, and pancreatic cancers. Some regimens have appeared to offer promise of improved postsurgical outcome, but no adjuvant treatment has established benefit in these sites.