Watch-and-wait Therapeutic Approach in Locally Advanced Rectal Cancer: An Innovative or Inevitable Option for Rectal Preservation

Abstract

Currently, neoadjuvant chemoradiation followed by total mesorectal excision through a low anterior- or abdominoperineal resection (APR) is considered the standard treatment approach in the vast majority of patients with locally advanced rectal cancer. Even though LAR allows for anatomic rectal preservation, APR led to significant morbidity and compromised quality of life in rectal cancer patients. Approximately 10-40% of patients achieve clinical complete response (CCR) following neoadjuvant chemoradiation. Meanwhile, the rate of pathologic complete response (PCR) is usually less than CCR rate. Complete response rate may be improved by escalating radiation dose and optimizing (total) neoadjuvant chemotherapy. Therefore, at least one-fifth of patients will have the chance of rectal preservation using the watch-and-wait strategy. In this therapeutic strategy, patients should be followed up by an active surveillance protocol to detect early tumor regrowth and salvage radical surgery and will, therefore, provide comparable oncologic outcomes to those achieved in patients who undergo initial radical surgery. This review aimed to present the largest reports and highlight the most recent evidence and guidelines for watch-and-wait therapeutic strategy in patients with rectal cancer.