Background: There is widespread support in the published literature for routine adjuvant radiotherapy for rectal cancer.
Methods: In the present paper, the current evidence regarding adjuvant radiotherapy is reviewed, particularly the most recent studies of preoperative radiotherapy (usually including patients with Stage I, II and III disease) and postoperative radiotherapy (usually for Stage II and III disease), and meta-analyses. Two questions in particular are addressed: Does radiotherapy improve survival when surgeons are able to achieve low local recurrence rates with surgery alone? Does radiotherapy improve patients' quality of life?
Results: Radiotherapy has only been demonstrated to significantly improve survival in one individual study and one recent meta-analysis. The local recurrence rates in the no-radiotherapy arm of these studies were 27% and 21-36.5%, respectively. In more recent studies, with lower local recurrence rates reflecting modern surgical standards, no survival advantage has been found. It is currently unknown whether radiotherapy improves patients' quality of life. Studies have demonstrated that radiotherapy has acute and long-term detrimental effects on quality of life. While local recurrence can be very debilitating, it can also be asymptomatic, and the overall effect of the local recurrence statistics found in adjuvant therapy studies on quality of life has not been systematically investigated. The most recent studies demonstrate that 17-20 patients need to undergo adjuvant radiotherapy to prevent one local recurrence.
Conclusion: Current evidence does not support the widespread advocacy for routine adjuvant radiotherapy as used in the treatment arms of recent trials.