Role of Radiation in Intermediate-Risk Rectal Cancer

The treatment of rectal cancer has greatly evolved during the last several decades as a result of the understanding of the pathways of cancer spread, natural history of the disease, stages prognosis and prognostic markers. The tendency is clearly to move toward a more personalized approach to these patients based on preoperative staging and response to therapy. Although in the past we have been adding more treatment modalities to surgery to the point that every stage II/III cancer was treated with neoadjuvant chemo and radiotherapy followed by radical surgery by total mesorectal excision with or without sphincter preservation and more chemotherapy to follow, more recently this algorithm has been under discussion and scrutiny. Two of the major topics of controversy are: the use of local excision or even a watch-and-wait approach after a clinical complete response and the need for radiotherapy in the intermediate risk group. In this manuscript we will present the historical perspective that has brought the treatment of rectal cancer to the current standard of care and present the evidence supporting further investigation in the intermediate risk group.