Although the prognosis of cancer is much better than before, and many cancers are no longer incurable, some cancers are still very difficult to treat, and people’s fear of cancer is still difficult to be eliminated for a while. Once a person is diagnosed with cancer, it is a serious blow psychologically and can cause heavy mental burden, and many people sink down rapidly, suffering from both tumor and mental torture, and the latter often accelerates the aggression of the patient significantly and strongly. Many patients are often struck down first by the mental blow. Therefore, after learning that a loved one is suffering from cancer, people unconsciously keep the news from the patient in order to reduce the mental stimulation of the patient, for fear of revealing any traces, so that it is one thing in front of the patient and another behind the scenes. Patients often begin to suspect in an atmosphere of uncertainty, and the “news” obtained from this kind of secret search forms a more sad and negative psychological barrier in the patient’s mind. Some think that if the patient does not know and cannot know the diagnosis of malignant tumor, he can not be told temporarily or for a longer period of time, so that the patient can be relieved of the emotional pressure and can recuperate from the treatment. However, many cancers require surgery, and some of them even require disfiguring and destructive surgeries, which are impossible to keep patients from knowing. After the patient knows the truth, he or she can actively cooperate with the treatment and post-treatment rehabilitation as requested by the physician. If a patient cannot obtain accurate information from his physician or pry reliable information about his condition from his family, he will pry information from his patients, nurses and other physicians, which is often inaccurate and unreliable. It is especially important that if the patient does not receive accurate and comprehensive information about his illness, he cannot make the right choice. Many patients’ families often complain that the patient is not cooperating with treatment, which in turn is often the result of concealing the disease. Therefore, many physicians tend to adopt the practice of giving direct information to patients about their illness. The World Health Organization’s expert committee has also pointed out that any concealment of the true nature of cancer is harmful and unhelpful. According to a survey conducted on cancer patients, the majority of patients are willing to know the truth about their illness and how it has changed during the course of the disease. Doing so is conducive to close cooperation with physicians and to arranging and handling various things at work, in life and at home. It is increasingly accepted by oncologists and patients that patients should be informed of the general knowledge of the disease, including its causes, symptoms and prognosis, and that scientific explanations should be given in a targeted manner in order to eliminate doubts and make them feel at ease to receive treatment. It is undoubtedly beneficial to patients and their treatment.