Long course chemoradiation for rectal cancer typically uses fluoropyrimidines. In the ARISTOTLE trial, 589 patients receiving neoadjuvant chemoradiation for rectal cancer were randomized to receive 45 Gy in 25 fractions and capecitabine with or without irinotecan. Adding irinotecan did not improve DFS (68% v 67%), it reduced the proportion of patients who completed RT (75% v 89%), and increased the rate of grade 3+ adverse effects (78% v 52%). | Sebag-Montefiore, Lancet Oncol 2026
