Local Excision of Clinical T3 Rectal Adenocarcinoma Showing Major Response(ycT0-1) After Neoadjuvant Chemoradiotherapy

Local Excision of Clinical T3 Mid- or Low-Rectal Adenocarcinoma Showing Major Response(ycT0-1) After Neoadjuvant Chemoradiotherapy: Prospective Multicenter Single-arm Phase II Clinical Trial

The purpose of this study is evaluation of the safety and the efficacy of transanal local excision in patients with cT3 rectal cancer which was downstaged into ycT0-1 after neoadjuvant chemoradiotherapy.

This study is a prospective multicenter single-arm phase II clinical trial. Rectal cancer patients with cT3 stage will receive neoadjuvant chemoradiotherapy, and be evaluated the response of the tumor in 6 to 10 weeks after completion of neoadjuvant chemoradiotherapy. For those who have good response (ycT0-1) will underwent transanal local excision under the patients' agree.

Inclusion Criteria:

• age: more than 20 years
• biopsy-proven adenocarcinoma of the rectum
• clinical staging, cT3NxM0
• Rectal cancer located 8 cm from the anal verge
• Restaging in 6-10 weeks after completion of neoadjuvant chemoradiotherapy, ycT0-1N0M0
• ECOG performance status 2 or less

Exclusion Criteria:

• Synchronous colon cancer or other malignancy
• Obstructing rectal cancer
• Pregnant or breast-feeding
• Receiving any other study agents
• History of prior colorectal cancer or inflammatory bowel disease
• Hereditary colorectal cancer (FAP, HNPCC)