The study is a multi agency prospective cohort study in China. The subjects were patients aged 18 \~ 75 years with colorectal cancer diagnosed by histopathology or cytology. They must be colorectal cancer patients who have at least one assessable tumor focus, need adjuvant therapy after radical surgery, and have not received neoadjuvant therapy， ECoG physical condition score ≤ 2 points. And they must be voluntarily participate in and sign informed consent.
The patients were randomly divided into PTC drug sensitivity test group and control group. The PTC drug sensitivity test group selected the adjuvant chemotherapy scheme according to the 3D drug sensitivity test results of micro tumor (PTC) in vitro. The control group made adjuvant chemotherapy strategy according to clinical experience.
The primary endpoint was the non inferiority test, and the 3-year disease-free survival rate was T-C \>- Δ
