Local Excision After Preoperative Chemoradiotherapy for Rectal Cancer: Results of a Multicenter Phase II Clinical Trial

BACKGROUND:Transanal local excision has been suggested as an attractive approach for patients with rectal cancer who show a major clinical response after preoperative chemoradiotherapy. OBJECTIVE:To evaluate the impact of transanal local excision on the local recurrence of rectal cancer in patients who had a major clinical response after preoperative chemoradiotherapy. DESIGN:Sequential 2-stage phase II study for early efficacy. SETTING:Multicenter study. PATIENTS:Patients with clinical T3 or low-lying T2 rectal adenocarcinoma that showed a major clinical response after a preoperative chemoradiotherapy. Eligible patients underwent a full-thickness transanal local excision. According to their histopathology, the patients staged as ypT0-1 were observed, while the remaining patients were recommended to undergo a subsequent total mesorectal excision. MAIN OUTCOME MEASURES:A local recurrence rate of ≤5% was set as a successful rate for stopping the trial early after the first stage. RESULTS:The study group included 63 patients. Before chemoradiotherapy, patients were staged as clinical T3 (n = 42) and T2 (n = 21). After the local excision, 43 patients fulfilled the criteria to be observed with no further treatment. Nine of the remaining 20 patients for whom a subsequent total mesorectal excision was recommended refused surgery. Two of these patients who refused surgery had intraluminal local recurrence; both had a ypT2 tumor and underwent salvage surgery. The estimated cumulative 3-year overall survival, disease-free survival and local disease-free survival were 91.5% (95% CI75.9–97.2), 91.0% (95% CI77.0–96.6) and 96.9% (95% CI80.3–99.5), respectively. LIMITATIONS:The time of follow-up is still short and the sample size is limited. CONCLUSIONS:Our data suggest that local excision is a good option for patients with a major clinical response after chemoradiotherapy. A longer period of follow-up is required to confirm these findings.