[Preoperative treatments of rectal cancers].

Surgery alone is no longer appropriate to the treatment of T3-T4 resecable rectal cancer. Preoperative chemoradiotherapy has recently been approved as the new standard treatment. This approach improves local control with local failure rate raranging now around 6-8%. However, it does not impact on overall survival. It becomes urgent to develop new concepts and a basic research in the understanding of the biological mechanisms that may explain the resistance of the micrometastatic process.