Adjuvant chemotherapy was unnecessary in pathological stage Ⅱ colorectal cancer following initial treatment of surgery without high risk factors of recurrences. The treatment efficacy of adjuvant chemotherapy for pT1-3N0M0 colorectal cancer following preoperational chemotherapy or chemoradiotherapy remains unclear. Part of clinical local advanced colorectal cancer(cTxN1-2M0), which turn out to be pT0-3N0M0 after preoperational chemotherapy or chemoradiotherapy, might not really need adjuvant chemotherapy due to the down-stage efficacy of the preoperational treatments, or the misleading by lymph nodes false-positive imaging diagnosis.
preoperative clinical tumor stage III （TxN1-2M0）CRC
pathological proved CRC adenocarcinoma by endoscopic biopsy
Post operational pathological T0-3N0M0 without high risk factors of recurrence
Patient able to understand and sign written informed consent
Other malignant tumors history.
Complications need emergency surgery (occlusion, sub-occlusion, massive hemorrhage and abscesses).
Colorectal tumor extension towards abdominal wall and/or adjacent organ making liver R0 resection impossible immediately.
Non resectable lymph node metastasis.