Trimodality therapy with neoadjuvant chemoradiation (nCRT), surgery, and adjuvant chemotherapy is the standard treatment for locally advanced rectal cancer. There is evidence that surgery can be deferred in patients with complete response (CR) to nCRT, a strategy termed “watch-and-wait” (WW). We compare WW to surgery in patients with CR to nCRT.

We reviewed records of patients treated with nCRT for nonmetastatic rectal cancer at our institution. Complete endoscopic response (CER) was defined as negative digital rectal exam and negative endoscopy at the end of neoadjuvant therapy (NAT). Clinical complete response (cCR) was defined as CER with negative rectal MRI. Patients with CER refusing surgery were offered WW, which included strict surveillance with digital rectal exam and endoscopy.

From January 2015 through February 2019, 465 patients completed nCRT; 406 patients had response assessment, of which 95 (23%) had CER. Of these patients, 53 patients underwent WW and 42 patients had surgery. Median follow-up was 35 months. In the WW group, 3-year freedom from local regrowth was 85%. In the surgical and WW groups, 3-year overall survival, rectal cancer-specific survival, and freedom from nonregrowth recurrence were 100% vs 88% (p = 0.03), 100% vs 95% (p = 0.16), and 92% vs 85% (p = 0.36), respectively. Of the 6 WW patients with local regrowth, 5 (83%) eventually developed distant recurrence.

WW in lieu of surgery appears to be a safe and feasible treatment approach for patients achieving CR to nCRT. Careful evaluation to confirm cCR after nCRT is valuable in selecting patients for WW.