Stage 4 adenocarcinoma of the ascending colon means that the tumor at the ascending colon is adenocarcinoma, which is staged according to the size of the tumor, lymph node metastasis, and distant metastasis, and it belongs to stage 4. Ascending colon cancer is a common malignant tumor in gastrointestinal tract, and adenocarcinoma is a common pathological staging of colon cancer. Clinically, TNM staging will be carried out according to the size of tumor diameter or invasion, regional lymph node metastasis, distant metastasis, etc., which is used to assess the condition, guide the treatment plan and judge the prognosis. For ascending colon cancer stage 4, it mainly includes stage 4A, stage 4B, and stage 4C. stage 4A means that regardless of the tumor size or regional lymph node metastasis, the tumor has spread to 1 distant organ or lymph node, but has not spread to the distal part of the peritoneum. Stage 4B is defined as spread to more than 1 distant organ or lymph node without spreading to the distal portion of the peritoneum.Stage 4C is defined as the tumor having spread to the distal portion of the peritoneum regardless of tumor size or regional lymph node metastasis. Stage 4 adenocarcinoma of the ascending colon already has distant metastasis and belongs to the advanced stage, so it is recommended to seek medical treatment in time and under the guidance of professional doctors, rational and standardized treatment can improve the quality of survival and prolong the life cycle.