Randomized Trial of Primary Surgery Followed Selective Radiochemotherapy for Rectal Cancer With MRI Negative CRM

Randomized Trial of Primary Surgery Followed Selective Radiochemotherapy Versus Conventional Preoperative Radiochemotherapy for Locally Advanced Rectal Cancer With MRI Negative Circumferential Margin

The purpose of this study is to determine whether primary radiotherapy can be omitted for the locally advanced rectal cancer with Magnetic Resonance Imaging (MRI) negative circumferential margin.

The preoperative radiochemotherapy with fluorouracil followed surgery is the standard therapy for patients with locally advanced rectal cancer. However, the necessity of radiotherapy has been questioned for a long time especially for patients with enough circumferential margins. Moreover, indiscriminate radiotherapy will result Irreversible ovarian dysfunction for female. In the past decade, there were two major progresses for colorectal cancer. Firstly, oxaliplatin with fluorouracil has become the standard adjuvant chemotherapy for advanced colon cancer. Oxaliplatin improved the survival of colon cancer patients than single fluorouracil. Our experience showed that oxaliplatin with fluorouracil could improve the prognosis of rectal cancer without radiotherapy. It has been proven that oxaliplatin should not add to radiotherapy for rectal cancer. However, whether oxaliplatin can replace radiotherapy for certain rectal cancer patients is still unknown. Secondly, Magnetic Resonance Imaging (MRI) has been proven that can predict the circumferential margin status for rectal cancer. Now, preoperative MRI scan can recognize the rectal cancer patients with low recurrence risk. The radiotherapy may be omitted to the patients with low recurrence risk. This study is a randomized controlled trial to compare the 3-year disease-free survival (DFS) differences of group of experiment (the patients receive primary surgery followed selective radiochemotherapy) and group of control (the patients receive indiscriminate preoperative radiochemotherapy followed surgery) for locally advanced rectal cancer with negative MRI circumferential margin.

Inclusion Criteria:

• Rectal adenocarcinoma or mucinous adenocarcinoma that is 6-12 cm from the anal verge.
• MRI scan confirmed cT3N0 or cT4aN0 or cT1-4aN+ mid rectal cancer (6-12cm from the anal verge).
• MRI scan confirmed more than 1 mm circumferential margin.
• Age 18-75 years old.
• Without distant metastasis.

Exclusion Criteria:

• Malignant history.
• Contraindications of MRI scan.
• Contraindications of radiotherapy.
• Contraindications of chemotherapy.
• Pregnancy.
• Multidisciplinary team thinks that the patient is unsuitable to take part in research (For example, there are obvious regional lymph nodes involved in low rectal cancer patients who are thought with high risk of recurrence).
• Refuse to take part in research.