Perioperative radiotherapy +/- chemotherapy in rectal cancer.

Locoregional failure which occurs in 25%-50% of patients with rectal cancer undergoing potentially curative surgery, can be significantly reduced by either postoperative adjuvant irradiation and also by preoperative radiotherapy. In view of the possible local side effects/complications, optimal irradiation techniques including accelerator and 3-4 field techniques are mandatory. Combined treatment consisting of radiotherapy plus chemotherapy appears to be more efficient than pelvic irradiation alone. It seems that reductions in the rate of pelvic and extrapelvic tumor recurrences which are not dramatic but of clinical significance are followed by an improved survival. The 1990 Consensus conference of the National Institute of Health recommended combined postoperative radiotherapy and chemotherapy for patients with T3N0, T4N0 and any TN1-3 rectal cancer. For future trials, the main goal has to be optimization of radiotherapy plus chemotherapy in the perioperative treatment of rectal cancer. The most important unanswered question is whether the highest therapeutic ratio is obtained by pre- or postoperative treatment.