Multicenter Study on Laparoscopic Versus Open PANP-TME for Male Mid-low Rectal Cancer Patients

Inclusion Criteria: * Age from over 20 to under 60 years * Primary rectal adenocarcinoma confirmed pathologically by endoscopic biopsy * Mid-low rectal cancer (distance from anal edge≤12cm); cT1-3, N0-3, M0 at preoperative evaluation according to the AJCC Cancer Staging Manual Seventh Edition * Expected curative resection through both L-PANP-TME and O-PANP-TME; Performance status of 0 or 1 on ECOG (Eastern Cooperative Oncology Group) scale * ASA (American Society of Anesthesiology) score class I, II, or III; Written informed consent * Urinary and sexual function normal preoperatively Exclusion Criteria: * Women during pregnancy or breast-feeding * Severe mental disorder * History of previous pelvic surgery * Enlarged or bulky regional lymph node diameter over 3cm by preoperative imaging * History of other malignant disease within past five years * History of unstable angina or myocardial infarction within past six months * History of cerebrovascular accident within past six months * History of continuous systematic administration of corticosteroids within one month * Contraindication of heart, brain, lung, etc dysfunction * Requirement of simultaneous surgery for other disease * Emergency surgery due to complication (bleeding, obstruction or perforation) caused by rectal cancer * Rectal cancer invades surrounding tissues * Existence of genuine incontinence or severe stress incontinence preoperatively