September 18

Results of the EORTC Radiation Oncology Group Trial 22921 published in the New England Journal of Medicine

September 14, 2006

The EORTC Radiation Oncology Group Trial 22921 trial was designed to answer two questions: Does adding chemotherapy to preoperative radiotherapy augment the local effect of the radiotherapy and the overall survival of the patients? And can pre-or postoperative chemotherapy or both improve patient survival and progression-free survival?

Clinical patients with stage T3 or T4 resectable rectal cancer were randomly assigned to one of four different treatments, to receive

- preoperative radiotherapy, or
- preoperative chemoradiotherapy, or
- properative radiotherapy and postoperative chemotherapy; or
- preoperative chemoradiotherapy and postoperative chemotherapy.

The primary endpoint of the study was overall survival.

The results of this randomized trial involving 1011 patients indicate that the addition of fluorouracil-based chemotherapy to preoperative radiotherapy has no statistically significant effect on the survival of patients with resectable rectal cancer.  Similarly, the addition of post-operative chemotherapy did not significantly improve progression-free survival nor overall survival, although the results suggest a trend towards improvement in both endpoints, starting between 2 to 5 years after treatment initiation. Further research is needed to identify if patient subgroups of good prognostic might significantly benefit of adjuvant chemotherapy.

Although preoperative chemotherapy and/or post-operative chemotherapy was associated with a significant increase in local control, the authors take it to be unnecessary to intensify this regimen to further decrease local recurrence, or to prevent metastases. Instead, future trials should focus on eradicating micrometastases, as the incidence of distant metastases was about three times that of local recurrences.

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Full reference:

Jean-François Bosset, M.D., Laurence Collette, Ph.D., Gilles Calais, M.D., Laurent Mineur, M.D., Philippe Maingon, M.D., Ljiljana Radosevic-Jelic, M.D., Alain Daban, M.D., Etienne Bardet, M.D., Alexander Beny, M.D., Jean-Claude Ollier, M.D., for EORTC Radiotherapy Group Trial 22921, Chemotherapy with Preoperative Radiotherapy in Rectal Cancer, New England Journal of Medicine 2006; 355:1114-23.

For further information on the trial, please contact the corresponding author:

Jean-François Bosset, MD
Besançon University Hospital
Department of Radiotherapy
Blvd.Fleming
F-25030 Besancon CEDEX
France
jean-francois.bosset@ufc-chu/univ-fcmte.fr