In the clinic, I have a lot of patients who come to me with questions about whether or not they should have their pleural fluid pumped. This is because these patients may have been told by their visiting physicians that the pleural fluid does not need to be pumped and that it is useless to do so. In fact, I know that they are concerned about how the pleural fluid should be treated. Why do many doctors tell patients that it is useless to have their pleural fluid pumped? Because cancerous pleural fluid is caused by the cancer cells destroying the tissues of the lung, mainly the pleura, causing the pleural fluid to keep leaking out. If the pleural fluid is simply pumped out, it is really useless, and it will grow back in 2-3 days, and a lot of nutrition may be lost. Of course, if left unattended, the pleural fluid will increase, causing breathing difficulties and even threatening life. So shelving is not a good solution either. In the author’s 17 years of experience, the key is to provide effective treatment. So what is effective treatment? Tumor is a systemic disease, so systematic systemic treatment is indispensable. These systemic treatments can help to reduce the pleural fluid, but these treatments are not effective enough. Local treatment is the key to control the pleural fluid. Pleural fluid exists between two layers of pleura. Therefore, the previous local treatment, which was intrapleural injection of chemotherapy drugs or other drugs, aimed to cause adhesions between the pleura to achieve the purpose of having no place for the pleural fluid. In order to achieve adhesion, some people have even tried proprietary Chinese medicines, such as Rangeolene milk. The results were not satisfactory. Even if the treatment is slightly effective, it causes adhesions to the lung tissue. The result is that the pleural fluid forms a separation in the chest cavity, and the re-growth of the pleural fluid within the separation causes difficulties in subsequent treatment. Worst of all, adhesions can cause unbearable pain. Even if the pleural fluid is reduced, the pain is still unbearable. Because of the drawbacks and very poor efficacy of these traditional local treatment measures to control pleural fluid, some doctors are so frustrated that they simply tell patients not to have their pleural fluid pumped and treated, but only to do systemic treatment. However, the constant growth of pleural fluid can cause breathing difficulties. The progression of the pleural fluid is faster than the growth of the tumor itself. So without active action, one will die from the breathing difficulty caused by the pleural fluid rather than the tumor itself. In addition, prolonged chest tightness and shortness of breath will also damage the patient’s own ability to fight the disease. So is there any possible treatment that can control the pleural fluid without causing adhesions to the pleura? From this idea, the most ideal way to control pleural fluid is by controlling the growth of tumor cells and at the same time having a treatment method that will not cause adhesions. In addition, considering that patients in the state of pleural effusion are weak, the choice of chemotherapy drugs will have a large number of side effects and should be avoided as much as possible. The treatment method without toxic side effects or the treatment method with the least side effects is chosen as the best. Therefore, biological therapy becomes the first choice, and our choice is gene therapy. The most critical factor to control the destruction of the pleura by tumor cells is that the drug can reach the tumor lesion. By direct intrathoracic injection, the gene drug is combined directly on the tumor lesion on the pleura. This genetic drug selectively destroys tumor cells and has no effect on normal cells, so the effect is then very obvious and has no toxic side effects. Not only the chest tightness and shortness of breath were relieved immediately, but in some cases, no reappearance of pleural fluid was seen for 3 months after the disappearance of pleural fluid. Since there are no toxic side effects caused by chemotherapy, it is also completely tolerable for people who have been ineffective after several chemotherapy treatments and are physically weak. Usually after two treatments and four days, immediate results can be seen. Therefore, it is not terrible to have pleural fluid, science is progressing, and pleural fluid can be gradually controlled.