Objective To explore the safety of local excision and watch and wait (W&W) strategy in patients with mid-low rectal cancer who achieved clinical complete response (cCR) or near-cCR after neoadjuvant chemoradiotherapy (nCRT). MethodsWe retrospectively reviewed patients with mid-low rectal cancer who achieved cCR or near-cCR after nCRT at Peking Union Medical College Hospital between July 2017 and July 2023 and divided them into two groups based on their treatment strategy: local excision group (n=30) and W&W group (n=37). The primary outcome was disease free survival (DFS), and the secondary outcomes were overall survival (OS), recurrence-free survival (RFS), and metastasis-free survival. ResultsBaseline characteristics (including age, gender, and so on) were balanced and comparable between the two groups (P>0.05). Postoperative pathology in the local excision group showed ypT0 in 16 cases (53.3%), ypT1 in 3 cases (10.00%), ypT2 in 10 cases (33.3%), and ypT3 in 1 case (3.3%). Among the 10 cases of cCR in the local excision group, 7 cases (70.0%) achieved a pathological complete response. Among the 20 cases of near-cCR in the local excision group, 9 cases (45.0%) achieved pathological complete response. The median follow-up time was 38 months (range, 2 to 74 months). In the W&W group, tumor regrowth occurred in 13 cases (35.1%), distant metastasis in 7 cases (18.9%), and cancer-related death in 4 cases (10.8%); in the local excision group, local recurrence occurred in 3 cases (10.0%), distant metastasis in 6 cases (20.0%), and cancer-related death in 3 cases (10.0%). The local recurrence/relapse rate was higher in the W&W group than that in the local excision group (χ2=5.758, P=0.016), while no significant differences were found in the distant metastasis rate (χ2=0.013, P=0.911) or mortality (χ2=0.012, P=1.000). The local excision group had superior DFS (HR=0.373, P=0.031) and RFS (HR=0.238, P=0.014) compared with the W&W group. However, no significant differences were found in OS (HR=0.780, P=0.745) or metastasis-free survival (HR=1.027, P=0.962). ConclusionsIn patients with mid-low rectal cancer who achieved cCR or near-cCR after nCRT, given the limited sample size and number of events in this study, local excision showed potential advantages in improving DFS and RFS, whereas OS, distant metastasis rate, and mortality were comparable between the two groups.