DO WE NEED ADJUVANT TREATMENT FOR RECTAL-CANCER

Recent studies have shown improved local control of rectal cancer in p atients receiving preoperative radiotherapy. The reduction of local re currence is about 50% both after 25 Gy in 5 days and 40 Gy over 4 week s. Furthermore an improvement in survival of about 20% has been found. The long-term side-effects are still not fully evaluated. Adjuvant ch emotherapy studies in Dukes' C patients have shown a significant incre ase in survival of between 22 and 39%. An initial study using 17-1A an tibodies also in Dukes' C patients has shown a 30% increase in surviva l rate. However, a drawback of the trials that tested adjuvant treatme nt 5 to 10 years ago is that they do not reflect the modern surgical t echnique using perimesorectal clearance and total mesorectal excision. Centres not using adjuvant therapy are now reporting local recurrence rates of 5-10%, which is superior to surgery plus adjuvant therapy in all previously published trials. It is therefore urgent to study the effects of preoperative irradiation in patients operated on with the c urrent surgical technique and carefully balance the side-effects again st the benefits. The aim must be to obtain knowledge of how to select a subgroup of patients who definitely needs preoperative radiotherapy, e.g. those undergoing an abdominoperineal excision. Systemic adjuvant therapy is probably increasing survival rate in Dukes' C patients but more studies are necessary, particularly with the 17-1A antibody.