According to a new study published online in the journal Annals of Oncology, researchers have found that postoperative irinotecan should not be added to a fluorouracil plus leucovorin adjuvant regimen for the treatment of patients with optimally resected stage II-III rectal cancer.

For the study, researchers enrolled 357 patients with stage II-III rectal cancer who underwent surgery to remove the tumor between March 1999 and December 2005. Patients were randomly assigned to receive flurouracil plus leucovorin with or without irinotecan.

Results showed that with a follow-up of 156 months, the disease-free survival was in favor of the irinotecan arm but did not reach statistical significance (HR = 0.80; P = 0.154).

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Overall survival also favored the experimental arm but did not reach statistical significance either (HR = 0.87; P = 0.433).

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Researchers found that the 5-year disease-free survival was 58% in the fluorouracil/leucovorin only arm and 63% in the irinotecan arm.

The 5-year overall survival was 74% and 75% in the control arm and experimental arm, respectively.

In regard to safety, patients who received irinotecan experienced more neutropenia and diarrhea compared with the control arm.


  1. Delbaldo C, Ychou M, Zawadi A, et al. Postoperative irinotecan in resected stage II-III rectal cancer. Final analysis of the French R98 intergroup trial. Ann Oncol. 2015. [Epub ahead of print]. doi: 10.1093/annonc/mdv135.