Compared curative effect，safety and compliance between concurrent chemoradiotherapy and chemo-chemoradio-chemo sequential therapy in locally advanced mid/low rectal cancer.

The patients were divided into two arms according to the defined conditions (pathology rectal adenocarcinoma；distal distance of tumor from anal verge < 10cm；TNM staging T3-4N0-2；no distant metastasis；Karnofsky score≥70) in this prospective, single center, open, non randomized trail (arm A:concurrent chemoradiotherapy, arm B:sequential therapy). Regimens:Arm A:50Gy,2Gy/day per time, 5 days a week, for 5 weeks. +capecitabine 850mg/m2 bid on the day accept radiotherapy. Rest for 8 weeks. Arm B: XELOX 2 cycles (oxaliplatin 130mg/m2 ivgtt 2-6h day 1, capecitabine 1000 mg/m2 Bid day 1-14, repeat every 3 weeks ) → 50Gy,2Gy/day per time, 5 days a week, for 5 weeks.+capecitabine 850mg/m2 bid on the day accept radiotherapy → XELOX 1 cycle. Rest for 2 weeks. Evaluate pre chemotherapy, pre radiotherapy and pre surgery individually. Surgeries followed TME(total mesorectal excision) and PANP(pelvic autonomic nerve preservation) for patients in both arms. Take pathological evaluation of tumors. Take XELOX therapy till 6-8 cycles(pre and after surgery total). Follow up according the schedule.

Inclusion Criteria:

• Pathology rectal adenocarcinoma
• Distal distance of tumor from anal verge < 10cm
• TNM staging T3-4N0-2(MRI)
• No distant metastasis
• Karnofsky score≥70
• Female patients need contraception during the test
• Postmenopausal women for at least 12 months, expect pregnancy possibility
• Patients did not receive chemotherapy, radiotherapy in any form before
• No other severe related diseases (such as other tumor, severe cardiac and central nervous system diseases, etc.)

Exclusion Criteria:

• Be treated by radiotherapy, chemotherapy or tumor biological therapy before
• Received immunosuppressive therapy (including corticosteroids)
• Participated in other clinical trial(s) in 1 month
• With malignant tumor of colon
• Peripheral neuropathy (WHO I level and above)
• Neurological or psychiatric abnormalities affecting cognition , including central nervous system metastasis
• Severe allergies or allergic history
• Severe pulmonary or heart disease
• Pregnant or lactation or refuse contraception during the test
• Suffering other malignant tumors in past