Topic Highlight
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Dec 14, 2013; 19(46): 8489-8501
Published online Dec 14, 2013. doi: 10.3748/wjg.v19.i46.8489
Neo-adjuvant radiotherapy in rectal cancer
Bengt Glimelius
Bengt Glimelius, Department of Radiology, Oncology and Radiation Science, Uppsala University, SE-751 85, Sweden
Author contributions: Glimelius B contributed to the manuscript.
Supported by Swedish Cancer Society
Correspondence to: Bengt Glimelius, MD, Professor of Oncology, Department of Radiology, Oncology and Radiation Science, Uppsala University, S-75105 Uppsala, SE-751 85, Sweden. bengt.glimelius@onkologi.uu.se
Telephone: +46-18-6115513 Fax: +46-18-6111027
Received: September 10, 2013
Revised: October 17, 2013
Accepted: November 1, 2013
Published online: December 14, 2013
Processing time: 98 Days and 13.8 Hours
Abstract

In rectal cancer treatment, attention has focused on the local primary tumour and the regional tumour cell deposits to diminish the risk of a loco-regional recurrence. Several large randomized trials have also shown that combinations of surgery, radiotherapy and chemotherapy have markedly reduced the risk of a loco-regional recurrence, but this has not yet had any major influence on overall survival. The best results have been achieved when the radiotherapy has been given preoperatively. Preoperative radiotherapy improves loco-regional control even when surgery has been optimized to improve lateral clearance, i.e., when a total mesorectal excision has been performed. The relative reduction is then 50%-70%. The value of radiotherapy has not been tested in combination with more extensive surgery including lateral lymph node clearance, as practised in some Asian countries. Many details about how the radiotherapy is performed are still open for discussion, and practice varies between countries. A highly fractionated radiation schedule (5 Gy × 5), proven efficacious in many trials, has gained much popularity in some countries, whereas a conventionally fractionated regimen (1.8-2.0 Gy × 25-28), often combined with chemotherapy, is used in other countries. The additional therapy adds morbidity to the morbidity that surgery causes, and should therefore be administered only when the risk of loco-regional recurrence is sufficiently high. The best integration of the weakest modality, to date the drugs (conventional cytotoxics and biologicals) is not known. A new generation of trials exploring the best sequence of treatments is required. Furthermore, there is a great need to develop predictors of response, so that treatment can be further individualized and not solely based upon clinical factors and anatomic imaging.

Keywords: Chemotherapy; Chemoradiotherapy; Local control; Multidisciplinary; Organ preservation; Radiotherapy; Randomized trials; Rectal cancer

Core tip: Neo-adjuvant radiotherapy is beneficial to many rectal cancer patients since it reduces the risk of a local failure. Provided surgery is optimized, it does not substantially improve overall survival. This review describes the results of the randomized trials that form the basis for the present treatment recommendations. It also pinpoints reasons for differences in the care of rectal cancer patients seen worldwide. Finally, the concept of organ preservation is critically discussed.