Current Status of Nonoperative Management (Watch and Wait) for Rectal Cancer

Abstract

Organ preservation in cases with rectal cancer with nonoperative management has developed as a novel promising strategy in recent years. This strategy avoids total mesorectal excision in patients who achieve clinical complete response (cCR) after neoadjuvant chemoradiotherapy. Multiple studies reported comparable oncologic outcomes of nonoperative management and conventional total mesorectal excision. With the recent development of total neoadjuvant therapy with a higher cCR rate, more patients with rectal cancer would likely benefit from nonoperative management.

In contrast to Western countries, neoadjuvant chemoradiation is not a standard treatment for rectal cancer in Japan, which greatly hinders the development of nonoperative management. On the other hand, Japanese surgeons have advantages in developing this strategy, including meticulous endoscopic assessment using magnifying chromoendoscopy and the widespread use of minimally invasive surgery. In this review article, the rationale, indications and outcomes of nonoperative management for rectal cancer are discussed.