[Chemoradiation combined with total mesorectal excision for patients with locally advanced rectal cancer]

Rectal cancer is characterized by a high rate of local recurrence. Although it is widely believed that local control results in improved patient outcome, its strategy is still controversial. In Japan, total mesorectal excision (TME) or tumor-specific mesorectal excision (TSME) with pelvic sidewall dissection is regarded as the standard procedure, while TME or TSME with preoperative chemoradiotherapy (CRT) is common in Western countries. Most clinical data have indicated that preoperative CRT is not associated with improved long-term survival but with a lower incidence of local recurrence. In addition, CRT is known to enhance the severity of impaired sphincter function. Currently, trials using CRT regimens with newly developed chemotherapy agents are ongoing to elucidate the effect on the control of distant metastasis. According to clinical reports, the prognosis of Japanese patients undergoing surgery alone is as favorable as that in patients undergoing surgery plus CRT in the West, which implies that CRT is not a necessary treatment but a selective option. The precise prediction of tumor response and advances in CRT regimens resulting in better survival may improve the treatment of rectal cancer in the future.