Systemic treatment of patients who have colorectal cancer and inflammatory bowel disease.

Colorectal cancer is the most common malignant complication in patients who have IBD. The disease is difficult to diagnose because there is an overlap in symptoms in patients who have colon cancer and those who have IBD. Much has been learned about the incidence of colorectal cancer in patients who have IBD and its correlation with disease activity, duration, and anatomic location; however, almost no data are available regarding specific therapeutic considerations during adjuvant or palliative chemotherapy for these patients with respect to their underlying disease. Patients who have IBD who develop colorectal cancer are at higher risk for developing severe diarrhea during chemotherapy that may be due to the toxic effects of cytotoxic drugs or a flare of the IBD. Continuous infusional 5-FU alone, in combination with leucovorin, or in combination with oxaliplatin (FOLFOX) seems to be tolerated best. Bolus infusions of 5-FU (Roswell Park or Mayo regimens) and combination therapy of irinotecan with 5-FU should be avoided because of severe diarrhea and the possibility of sepsis. When diarrhea develops or worsens, empiric aminosalicylates may be given. Although it is theoretically possible that anti-EGFR therapies could affect IBD activity adversely, clinical experience with cetuximab in patients who have colorectal cancer has not shown any significant gastrointestinal side effects. Therefore, it seems reasonable to use it in patients who have colorectal cancer and IBD. The administration of bevacizumab has been associated with rare episodes of intestinal perforation; it should be used with great care in patients who have IBD. More studies and an integrative, multidisciplinary approach from oncologists and gastroenterologists are needed to provide optimal care for patients who have IBD during chemotherapy for colorectal cancer