Resectable rectal cancer: which patient does not need preoperative radiotherapy?

It is well known that some patients with resectable rectal cancer benefit from preoperative radiotherapy in combination with or without chemotherapy. In order to reduce local recurrence and improve long-term survival, current guidelines advocate such neoadjuvant treatment in UICC (Union for International Cancer Control) stage II and III patients. However, the vast majority of patients may be adequately treated by rectal resection with total mesorectal excision (TME) alone. Recent evidence suggests an overtreatment of patients leading to unnecessary exposure to acute and long-term toxicity of radiation therapy. The question which consequently arises is which patient does not need preoperative radiotherapy. Improvements in MRI combined with better understanding of prognostic indicators suggest that patients with UICC stage I tumors, with tumors more than 12 cm proximal the anal verge can and patients with a circumferential resection margin ≥ 2 mm as assessed by preoperative MRI might be managed by radical surgery with adequate TME alone.