Despite advances in preoperative therapy, many patients with locally advanced rectal cancer still develop distant metastases.In this randomized trial, adding irinotecan to preoperative capecitabine-based chemoradiotherapy failed to improve disease-free or overall survival.Addition of the topoisomerase I inhibitor resulted in more adverse events and also decreased radiotherapy and capecitabine compliance.
Adding concurrent irinotecan to capecitabine-based chemoradiotherapy failed to improve disease-free survival (DFS) and other outcomes in patients with locally advanced rectal cancer, a phase III trial showed.
In patients with MRI-defined tumors, DFS at 3 years was virtually the same with or without the topoisomerase I inhibitor (68% vs 67%; HR 0.91, 95% CI 0.68-1.23, P=0.54), reported researchers led by David Sebag-Montefiore, MD, of the University of Leeds in England.
Irinotecan did not improve rates of histopathologic complete response over the standard approach (19% vs 17%), and overall survival was no different as well, with 3-year rates of 88% and 83% (HR 0.97, 95% CI 0.69-1.37, P=0.86), according to findings detailed in Lancet Oncology.
Perhaps explaining the lack of oncologic benefit, "adding irinotecan resulted in decreased radiotherapy and capecitabine compliance," Sebag-Montefiore and co-authors noted, and the investigational arm had "a higher rate of adverse events including diarrhea and neutropenia."
