The risk of causing spread or metastasis when a tumor ruptures is different for different tumors. Overall, it may lead to the spread of tumor. Therefore, one of the basic principles of oncology that oncologic surgeons should master during their study phase is the principle of tumor-free, which needs to be strictly followed during surgery as well as the principle of asepsis in general surgery. The principle of tumor-free oncology: it refers to the application of various measures to prevent direct implantation or dissemination of cancer cells during tumor biopsy or surgical operations. Inappropriate surgical operations can lead to medical dissemination of cancer cells, therefore, oncologic surgery must follow the principle of tumor-free. For tumor biopsy, the surgeon uses a puncture needle to puncture the tumor endoscopically or under ultrasound/CT guidance to aspirate tissue cells for pathological examination. There is a possibility of needle tract metastasis with needle biopsy, but the probability is very low, especially with the current design of puncture cannula, which protects the tumor from direct contact with the needle tract tissue during removal. Incisional biopsy refers to the direct removal of a part of the tumor, leaving most of the tumor in the body. This type of biopsy is undesirable and leads to tumor rupture, and should be used with caution. Excisional biopsy refers to the complete removal of the tumor and the whole specimen for pathological examination. It is the first choice for general tumor biopsy because it can reduce the spread of tumor due to the complete removal of tumor and its integrity is guaranteed. This biopsy method is mainly applicable to small tumors located in subcutaneous, submucosal, breast, lymph nodes, etc., which are suitable for excisional biopsy. For biopsy of gastrointestinal tumors, it is mainly endoscopic forceps biopsy. These tumors located in the digestive tract will hardly lead to the spread of tumor cells in the digestive tract, and even if a single cancer cell is shed, it is difficult to survive in the environment of digestive fluid. Special note: For clinical diagnosis of suspected gastrointestinal mesenchymal tumor, biopsy is not required because mesenchymal tumor is different from general cancer and puncture biopsy can easily rupture and lead to the spread of tumor. If a mesenchymal tumor is suspected and judged on imaging to be capable of radical resection, it must not be taken for biopsy and treated by direct surgery, and then decide whether to follow up with medication after surgery according to the pathology. Unless, the tumor is large or invades the surrounding tissues and organs, which cannot be radically operated and needs preoperative drug treatment, then puncture biopsy is needed and clear pathological results are available before drug treatment. At this point, although there is a risk of tumor spread, the benefits outweigh the disadvantages when compared to the overall treatment needs, after all, the risk of metastasis after puncture is not particularly high. Tumor-free principles during cancer surgery: 1. Intraoperative probing and surgical operation sequence: 1) Intraoperative probing follows the principle from far to near: probing of abdominal or thoracic tumor should start from the organ tissue far from the organ where the tumor is located, and finally probe the organ where the tumor is located, and it is best to probe the lesion, and the lesion should not be directly touched by hand when probing. Nowadays, laparoscopic exploration may better follow the principle of tumor-free exploration. The surgical operation should be dissected from the periphery to the center of the tumor. If the tumor breaks through the plasma membrane, it is better to close the tumor wound with biologic adhesive to reduce the chance of tumor dissemination and detachment during the operation. (2) Treat the blood vessels around the tumor first, and then separate the tumor surrounding tissues: the blood metastasis of tumor cells is mainly cancer cells entering the veins and circulating with the blood. Operations such as pulling, squeezing or separating during surgery may make tumor cells enter the blood circulation and lead to the hematological dissemination of tumor cells. Therefore, ligating tumor blood vessels first in the early stage of surgical procedure and then carrying out surgical operations can reduce the chance of hematological dissemination of cancer cells. 2. no-touchisolationtechnique: whether it is open surgery or laparoscopic surgery, avoid direct contact with tumor with hands or instruments as much as possible to reduce the chance of tumor dissemination; use gauze pads to protect the edges of incision and normal organs around tumor during surgery; if tumor rupture is encountered during surgery, it should be completely aspirated and covered or wrapped with gauze pads. The tumor rupture should be thoroughly aspirated and covered or wrapped with gauze pad, and gloves and surgical instruments should be replaced. 3.Follow the principle of whole block resection: regardless of the size of the tumor, it is better to avoid resection in pieces and treat the tumor as a whole, generally not less than 3cm from the edge of the tumor. When resecting myofibrosarcoma, the affected muscle groups should be completely removed from the beginning to the end of the muscle. If the tumor involves the surrounding organs, but there is no distant metastasis, the whole tumor involved organs or tissues should also be removed. 4.More sharp separation and less blunt separation: The so-called sharp separation is to use cutting tools such as scalpel or scissors or electric knife or ultrasonic knife to cut tissues directly; blunt separation is to use hand or instrument to pull apart. Blunt separation is poor in thoroughness of clearing, and it is easy to cause tumor dissemination due to extrusion, so it should be avoided or used sparingly, and sharp separation should be used as much as possible. In addition, the use of electric knife cutting during surgery not only can reduce bleeding, but also can make the small blood vessels and lymphatic vessels be closed, and high frequency electric knife has the function of killing cancer cells, thus can reduce bloodway dissemination and local implantation. The severity of consequences of rupture varies with different types of tumors. If a huge mesenchymal tumor in the abdomen ruptures, recurrence is almost inevitable, and even a very small mesenchymal tumor, once it ruptures intraoperatively, is directly classified into a very high risk group, thus showing that for mesenchymal tumors, rupture is absolutely not allowed. There is also mucinous adenocarcinoma of the appendix or mucinous adenocarcinoma of the ovary, most of these types will form a cystic mass with an envelope. Once ruptured, the mucus spreads in the abdominopelvic cavity and is very difficult to be cleared, even with a lot of saline flushing. But for gastrointestinal cancers, for one thing, tumors are not easy to rupture, even if they are huge, these tumors rarely form cystic or liquid components, which are not easy to rupture; on the other hand, even if cancer cells are shed, they are not easy to form implantation nodules, which can almost always be flushed clean with a large amount of saline flushing after surgery. In conclusion, no matter what kind of tumor, it is important to try to avoid intraoperative medical rupture, which leads to tumor dissemination. Definitely, during the whole operation, all personnel involved in the operation should strictly follow the principles of tumor-free and asepsis to minimize or avoid medical-derived tumor dissemination.