To investigate the oncological outcome of lateral lymph node dissection in low rectal cancer based on MRI

Our study design is a multicenter, prospective, registry study.

We would enroll 268 patients with lower rectal cancer whose preoperative MRI showed laterally lymph node diameter ≥ 5mm.

The postoperative adjuvant chemoradiotherapy is determined by the pathological results. For patients of stage II and patients of stage III with unfavorable histologic features, six months of adjuvant chemotherapy of fluorouracil-based regimen with radiotherapy of 45.0 ~ 50.5 Gy are recommended.

The postoperative examination should be performed every three months in the first two years and every six months in the following three years.

Our study is expected to last five years, of which two years for recruiting patients, three years for follow-up.

Inclusion Criteria:

1. Age between 18-75 years old
2. Pathologically confirmed as rectal adenocarcinoma
3. The tumor is located in the middle or lower rectum
4. Preoperative MRI assessment is T2-4 N+M0
5. Lateral lymph node short diameter ≥ 5 mm (MRI)
6. Signed informed consent

Exclusion Criteria:

1. Previous history of malignant colorectal tumors
2. Multiple abdominal or pelvic surgeries were performed
3. Complicated with bowel obstruction, perforation or bleeding
4. Patients undergoing palliative surgery
5. Patients with severe liver and kidney dysfunction, cardiopulmonary dysfunction, blood coagulation dysfunction, or combined with serious underlying diseases that cannot tolerate surgery
6. Have a history of severe mental illness
7. Pregnant or breastfeeding women （8) Patients previously treated with iliac artery surgery (or its branches)

(9) R0 resection cannot complete (10) ASA grade ≥ IV

Lower rectal cancer patients with lateral lymph node short diameter ≥ 5 mm were included in the study. TME with lateral lymph node dissection was performed in these patients. LLN positive rate, local recurrence rate, 3-year overall survival rate, perioperative complication rate and quality of life were documented and analysed.

The data are available from Qian Liu upon request.

The data were available to all the researchers permanently after this study was done.

All the data will be available to all the relevant researchers in the world upon request. Email: liuqianncc@126.com