Proximally Extended Resection for Rectal Cancer After Neoadjuvant Chemoradiotherapy

Randomized Trial of Sphincter-Preserving Surgery With Proximally Extended Resection Margin on Bowel Function and Anastomotic Complication for Rectal Cancer Patients After Neoadjuvant Chemoradiotherapy

Neoadjuvant chemoradiotherapy has been recommended as the standard preoperative treatment for locally advanced rectal cancer. However, preoperative radiotherapy increases the risk of bowel dysfunction after sphincter-preserving surgery, for which patients suffer from incontinence, urgency, and unpredictability defecation problems. Furthermore, preoperative chemoradiotherapy is a potential risk factor of anastomotic leakage and stenosis after rectal cancer surgery.

Unhealthy anastomosis, with both ends of injured bowel segments after pelvic radiation, is a major concern. When conventional surgical procedures would retain part of sigmoid colon that has been included in the radiation target, sphincter-preserving surgery with proximally extended resection margin could provide an intact proximal colon limb for the anastomosis.

It is not known yet whether proximally extended resection improves postoperative bowel function or anastomotic integrity for patients with rectal cancer after neoadjuvant chemoradiotherapy. The proposed study will compare sphincter-preserving surgery with and without proximally extended resection margin, to observe the postoperative bowel function, as well as the incidence of anastomotic complication. This study will examine a new surgical strategy, which potentially benefits the patients undergoing neoadjuvant chemoradiotherapy.

Inclusion Criteria:

• Age: 18-75 years old
• ECOG performance status: 0-2
• Histologically confirmed adenocarcinoma of the rectum
• Distal border of the tumor located ≤ 12 cm from the anal verge
• Primary stage T3-4 or any node-positive disease
• Undergoing long-course 5-fluorouracil based neoadjuvant chemoradiotherapy
• Conventional fractionated radiotherapy of at least 45 Gy
• Resectable disease after neoadjuvant chemoradiotherapy
• No evidence of distant metastasis
• Amenable to sphincter-preserving surgery
• Tolerable to general anesthesia
• Provision of written informed consent

Exclusion Criteria:

• Prior or concurrent malignancies within the past 5 years except for effectively treated squamous cell or basal cell skin cancer, melanoma in situ, or carcinoma in situ of the cervix
• Synchronous colon cancer
• History of colorectal resection except appendectomy
• Acute intestinal obstruction or perforation
• Multiple visceral resection
• Abdominoperineal resection
• American Society of Anesthesiologists (ASA) class Ⅳ or Ⅴ
• Pregnant or nursing, fertile patients do not use effective contraception
• Serious cardiovascular disease, uncontrolled infections, or other serious uncontrolled concomitant disease
• Psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule