Ca is the abbreviation for cancer, and rectal cancer T2N0Mx is defined as a cancerous lesion invading the lamina propria without lymph node metastasis, and distant metastasis cannot be assessed. Ca is the abbreviation of “Cancer”, i.e. cancer, rectal Ca is rectal cancer. Rectal cancer is a malignant tumor originating from the mucosal epithelium of the rectum, and its occurrence is associated with adenomatous polyps, excessive fat intake, and heredity. Rectal cancer T2N0Mx is TNM staging, T refers to the situation of primary lesion, which means that the tumor invades the intrinsic muscular layer but not the plasma membrane layer; N refers to the situation of lymph node metastasis, and N0 refers to the absence of lymph node metastasis; M refers to the situation of distant metastasis, and Mx is the situation of distant metastasis that can not be assessed, and further imaging examination such as PET-CT is needed. Rectal cancer usually requires radical surgery, radiotherapy, chemotherapy and other comprehensive treatments. It is suggested that patients should consult the doctor in time, follow the doctor’s instructions for examination and treatment, and actively cooperate with the treatment to avoid delaying the aggravation of the condition.