Watch-and-Wait Strategy for Rectal Cancer With Complete Clinical Response After Neoadjuvant Therapy


Key Points

  • This was a single-center, retrospective analysis.
  • Following complete response to neoadjuvant therapy, a watch-and-wait strategy was associated with a high rate of rectal preservation and pelvic tumor control.
  • In the watch-and-wait group, patients with local regrowth had worse survival and a higher incidence of distant progression.

In a single-center retrospective case series analysis reported in JAMA Oncology, Smith et al found that a watch-and-wait approach was associated with a high rate of rectal preservation and pelvic tumor control in patients with rectal cancer with complete clinical response to neoadjuvant therapy, but survival was poorer in these patients with local tumor regrowth compared with patients found to have pathologic complete response (pCR) after total mesorectal resection.

Study Details

The study included data from patients diagnosed with rectal adenocarcinoma between January 2006 and January 2015 at Memorial Sloan Kettering Cancer Center. Patients either had a clinical complete response after completing neoadjuvant therapy and agreed to a watch-and-wait strategy of active surveillance and possible salvage surgery (n = 113) or underwent total mesorectal excision and were found to have pCR at resection (n = 136).

Compared with the pCR group, the watch-and-wait group had a higher median age (67.2 vs 57.3 years,  P < .001) and had disease closer to the anal verge (median height from anal verge = 5.5 vs 7.0 cm).

Treatment Outcomes

Median follow-up was 43 months.

A total of 22 local regrowths were observed in the watch-and-wait group, with all detected on routine surveillance and all treated by salvage surgery consisting of total mesorectal excision in 20 and transanal excision in 2. Pelvic control was maintained in 20 (91%) of the 22 patients after salvage surgery. No pelvic recurrences were observed in the pCR group. Overall, rectal preservation was achieved in 93 patients (82%) in the watch-and-wait group, including 91 with no local regrowth and 2 with local regrowth salvaged with transanal excision.

At 5 years, overall survival was 73% in the watch-and-wait group vs 94% in the pCR group; disease-free survival was 75% vs 92%; and disease-specific survival was 90% vs 98%. Risk for distant metastases was greater in patients in the watch-and-wait group with vs without local regrowth (36% vs 1%,  P < .001).

The investigators concluded, “A watch-and-wait strategy for select [patients with] rectal cancer who had a clinical complete response after neoadjuvant therapy resulted in excellent rectal preservation and pelvic tumor control; however, in the watch-and-wait group, worse survival was noted along with a higher incidence of distant progression in patients with local regrowth vs those without local regrowth.”

Philip B. Paty, MD, and J. Joshua Smith, MD, PhD, of the Colorectal Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, are the corresponding authors for the JAMA Oncology article.

Disclosure: The study was supported by the National Cancer Institute, American Society of Colon and Rectal Surgeons, Wasserman Colon and Rectal Cancer Fund, Berezuk Colorectal Cancer Fund, American Association of Cancer Research, and others. The study authors’ full disclosures can be found at

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