Generalizability of results from oncology clinical trials: Toxicity of irinotecan-based regimens in patients with metastatic colorectal cancer

6633 Background: The relevance of oncology clinical trial results in clinical practice depends on whether the trial participants are similar to the entire population of patients with the malignancy and whether the patients are treated similarly in both circumstances. Irinotecan treatments are associated with high rates of severe diarrhea, and may be even more toxic in patients with poor performance status and advanced age, who are usually not included in clinical trials. Methods: A retrospective chart review was performed including all non-trial patients with metastatic colorectal cancer treated with irinotecan-based chemotherapy (irinotecan monotherapy, FOLFIRI, IFL, XELIRI) from January 2004 to September 2006 at Juravinski Cancer Centre, Hamilton, Ontario, Canada. We aimed to determine the toxicity of these irinotecan regimens in clinical practice compared to those published in corresponding large phase 2 and 3 clinical trials. The primary endpoint was incidence of grade 3/4 diarrhea. A subgroup analysi...