Evidence supports adjuvant radiotherapy in selected patients with rectal cancer

Background: Much recent data have been published on the risk of local recurrence (LR) following curative surgery for rectal cancer and the impact of adjuvant radiation therapy (RT). With improvements in surgical technique apparently reducing the risk of LR, the relevance of older data upon which the current recommendations for adjuvant RT are based has been questioned. Methods: A focused review was undertaken of the published literature on the risk of LR following surgery for rectal cancer and the impact of adjuvant radiation. In particular the authors attempt to define how accurately the risk for an individual patient can be predicted, trends in reported LR rates over the time period of randomized trials, and the relevance of changing surgical and RT techniques. Results: Many of the perceived differences in published results can be explained by variations in study entry criteria, length of follow up and data recording. Comparisons between studies are most accurate when defined subsets of patients, such as those with stage III disease, followed for the same period of time, are considered. In parallel with improvements in surgical technique, which may have reduced the risk of LR, modifications to RT delivery have resulted in recent series not reporting an increased mortality in those patients treated with modern RT techniques. Conclusion: All of the available evidence supports the use of adjuvant RT in selected patients with rectal cancer. Ongoing studies will better define individual patient risk and the risk-benefit ratio of adjuvant RT.