[Adjuvant radio-chemotherapy of cancers of the rectum]

Since several years, surgery has been the gold standard for the treatment of stage B2 and C rectal cancer. Following high-quality surgery, local recurrences occurred in 24 and 53% of the cases, respectively. The adjuvant treatments is aimed at decreasing the probability of local recurrence and at increasing survival rates. While postoperative radiation therapy eradicates residual disease in these tumors, preoperative radiation therapy may also decrease the tumoral volume in order to make surgery easier. The improvement in radiation modalities has allowed an increase in the treatment dose with minimal side-effects. Several clinical studies have demonstrated the efficacy of pre- or postoperative radiotherapy. The objective of the combination of radiation and chemotherapy is to increase the local control and decrease the metastatic process. Chemotherapy associated with postoperative radiotherapy leads to better results than surgery alone or radiation therapy plus surgery, in terms of overall survival rates and disease-free survivals. Encouraging clinical trials using the preoperative combination have permitted the implementation of phase III studies that are still in progress. Although optimal modalities related to chemotherapy are still not clearly defined, the importance of each modality is discussed, particularly in regard to the combination of radiation and chemotherapy.