[Simultaneous radiochemotherapy in rectal tumors].
After about 30 years from the first trials on concurrent chemoradiation in the treatment of rectal carcinoma, a large experience in this field has been shared, both in terms of laboratory and clinical data. The possibility of concurrent chemoradiation to improve the clinical outcome and sphincter preservation in low rectal tumors has been extensively demonstrated. Great attention should be paid to the quality of radiation treatment and drug administration, to minimize the risk of therapy-related toxicity. The impact of preoperative chemoradiation on tumor control will be further clarified by the ongoing randomized studies, in terms of comparison with radiation therapy alone (EORTC study), "Total mesorectal excision" (Duch Study), postoperative chemoradiation (German CAO/ARO/AIO 94) and the potential role of adjuvant chemotherapy (EORTC and Italian study). A series of phase II studies will probably clarify the role of unconventional fractionation modalities (hyperfractionation, accelerated treatments) and of new concomitant chemotherapy (new drugs, chronomodulation) in terms of organ and sphincter preservation. A close cooperation between radiation oncologists, medical oncologists and surgeons is required.