Watch-and-wait Strategy against Surgical Resection for Rectal Cancer Patients with Complete Clinical Response after Neoadjuvant Chemoradiotherapy

Abstract

The watch-and-wait strategy offers a non-invasive therapeutic alternative for rectal cancer patients who achieved clinical complete response (cCR) after chemoradiotherapy. However, concerns about the oncological safety of this approach remain. This study aimed to investigate the long-term clinical outcomes of cCR rectal cancer patients who managed under watch-and-wait to those who underwent surgical resection. A total of 94 patients with stage II/III rectal adenocarcinoma who were identified as cCR after neoadjuvant chemoradiotherapy and adopted the watch-and-wait strategy were included and matched to cCR patients who underwent radical resection using 1:1 propensity score matching analyses. Survival was calculated and compared in the two groups using the Kaplan-Meier method with log rank test. Compared with cCR patients who underwent radical resection, patients who adopted the watch-and-wait strategy had more cases of local recurrence (14/94 versus 1/94), but most (12/14) were salvageable. Three-year non-regrowth local recurrence-free survival was comparable between the two groups (98% versus 98%, P = 0.506), but the watch-and-wait group has obvious advantage in sphincter preservation, especially for patients with tumor located within 3cm from the anal verge (35/39 versus 14/34, P<0.001). Three-year distant metastases-free survival (88% in the watch-and-wait group versus 89% in the surgical group, P = 0.874), three-year disease-specific survival (99% versus 96%, P = 0.643) and overall survival (99% versus 96%, P = 0.905) were also comparable between the two groups, though a trend of high rate of distant metastases was observed in patients who developed local regrowth(5/14) in the watch-and-wait group. The watch-and-wait strategy was safe, with similar survival outcomes but superior sphincter preservation rate as compared to those who had surgery for rectal cancer patients achieving cCR after neoadjuvant chemoradiotherapy, and could be offered as a promising conservative approach to invasive radical surgery.