Malignant tumors are now common diseases worldwide, seriously threatening human health. In many countries and regions, malignant tumors have surpassed cardiovascular diseases and become the first killer of human beings. Among the diagnosed tumor patients, 1/3 can be cured, 1/3 can prolong their lives, while the other 1/3 are incurable, thus tumor patients often worry about their lives. In the face of this serious situation, exploring the causes of tumors, developing new treatments, and giving more care to tumor patients have become the focus of today’s medical community. With the development of science and technology, the medical model has changed from the original single biomedical model to the bio-psycho-social medical model, and the research on tumor has also paid more and more attention to the role of psychosocial factors in the occurrence, development, treatment and rehabilitation of tumors, which gradually formed a new branch of oncology. Thus, a new branch of oncology has been gradually formed -psychological oncology. From the perspective of psychology, it elaborates the etiology of tumor, gives psychological guidance to normal people to prevent the occurrence of tumors, gives psychological support to tumor patients, and conducts rehabilitation guidance, and even hospice care. Psychology and Tumor Etiology Recent studies have shown that the etiology of tumors is multifaceted and complex, and psychosocial factors are one of the important aspects. Psychosocial factors act on the human body for a long time, leading to the dysfunction of central nervous system and endocrine function, weakening the body’s immune system function, thus leading to the occurrence of cancer. The Institute of Psychology of Chinese Academy of Sciences suggests that: long-term tension in work and study, uncoordinated interpersonal relationship between work and family, and major misfortune in life are three important factors of psychological carcinogenesis. 1. Stimulation factors: most cancer patients have encountered different degrees of life changes before the onset of the disease, and the loss of important emotions puts them in sorrow and loneliness for a long time. when this sorrow and loneliness reach an uncontrollable degree, they will be in a state of loss of control, which leads to the change of the internal environment of the organism and induces the growth of cancer cells. Engel et al. believe that psychology and physiology are closely related, and physiological function also participate in the expression of unconscious psychological conflicts. Therefore, many studies on the emotional state prior to the onset of cancer have emphasized the mental stress caused by major life changes, which puts the patient in an uncontrollable mood of despair. The most common psychological stressor of cancer is the emotional experience of losing a loved one. The death of a loved one typically occurs 6-8 months prior to the onset of cancer, and the resulting depression, despair, and unexpressed grief are often harbingers of cancer. As early as 1954, Stepheson found that a considerable number of patients with cervical cancer were dissatisfied with their sex life, and the incidence of events such as separation, divorce, and abandonment was also higher. Greer’s study of breast cancer patients showed that there was a clear relationship between the diagnosis of cancer and the occurrence of stimulating events such as the loss of a loved one in the recent past or in the past. Emotional factors: In the 2nd century A.D., Galen observed that women who were depressed were more prone to breast cancer than those who were cheerful. In recent years, the relationship between depression and cancer has been investigated through the use of various scales, and most of the retrospective studies have shown that negative emotions such as depression can increase the prevalence of cancer and the rate of death, i.e., negative emotions are more prone to cancer and can accelerate the development of cancer. This is consistent with the clinical observation that cancer patients with longer survival are often optimistic and positive. 3. Personality factors: Cancer is related to some specific personality attributes. Cancer is prone to occur in people with two personality traits: one is the lack of emotional expression or active emotional suppression; the other is in the face of emergencies, easy to produce a sense of disappointment, helplessness. C-type personality is overly patient, avoiding conflict, overly cooperative, yielding concessions, controlling negative emotions, and the pursuit of perfection. It is now believed that Type C personality is associated with the development of cancer. Case-control studies conducted by Wei Wu have also shown that introverted personality traits, repression and masking of emotional responses are risk factors for colorectal cancer. Psychological reaction of cancer patients: After learning their diagnosis, cancer patients will immediately feel a serious mental shock and experience psychological stress reaction, which is manifested as disruption of the normal order of daily life, depressed mood, even disoriented demeanor, decreased appetite, sleep disorder, weight loss, etc. Cancer patients have their own unique personality traits. Cancer patients have their unique personality characteristics: loneliness, irritability, dullness, self-mutilation, repression, denial, rebelliousness, self-restraint, self-doubt, poor ability of emotional release, and easy to experience despair. Its psychological state can be manifested as denial period, resentment, compromise, depression, acceptance of such five stages. 1. Denial period: After the patient learns about his diagnosis, the first reaction is to refuse to admit that he is suffering from cancer, suspecting that the diagnosis is wrong or mixed up with others, denying the doctor’s diagnosis, and most of the patients ask for a review. When the diagnosis is reconfirmed, the patient immediately develops a sense of loneliness and begins to close himself/herself off, unwilling to talk to others. They tend to detach themselves from normal life and lose their social status and role, and even become outside the society. According to Guan Zhongliang’s statistics, among 231 cancer patients, 100% of them had denial psychology. 2. Indignant period: After denial period, patients have to face the fact of malignant tumor, at this time, patients are indignant and very aggrieved, and this stage is most likely to have inner anxiety and fear. Due to the fact of “terminal disease” and the desire to live contradictory, patients are often very painful. Manifestations are accelerated heart rate, increased blood pressure, pale or flushed, muscle tension and so on. Wu Yanping has conducted psychological analysis on 123 cases of breast cancer patients, and the result shows that 97.5% of the patients have anxiety, and 33.3% of the patients show fear. 3.Compromise period: after the end of indignation, the actual fact of cancer still exists, therefore, patients have to recognize the diagnosis psychologically. And in the face of the disease often appear two kinds of differentiation, one kind of patients positively accept the diagnosis, think that since they can’t get rid of this destiny, why don’t they feel more fun in life in the limited time, they often cooperate with the treatment and care, and take the initiative to take part in the social activities; the other kind of patients accept the destiny in a negative way, think that they can’t fight with the destiny, and that the death is unavoidable, and they often alternate with anger and depression, which accelerate the cancer They often alternate between anger and depression, which accelerates the process of cancer. 4. Depression period: With the deterioration of the disease in the course of treatment, cancer patients are facing the threat of pain and death, and some of them are also under the pressure of medical expenses, and are disturbed by the fact that they have become a burden to their families. Patients often feel sad, lose confidence in treatment, and even have thoughts that life is worse than death. Li Ning in the 150 cases of cancer patients’ mental health status survey analysis shows that cancer patients’ depression symptom scores are significantly different from normal people. 5.Acceptance period: It can also be called the calm period. Patients not only endure the pain of surgery, chemotherapy, radiotherapy, etc. physically, but also undergo a series of mental journey mentally. In the advanced stage of cancer, patients often lose confidence in all kinds of treatment and show unusual calmness. The duration of the various psychological states of different patients varies, and the severity of the psychological reaction is also different, which is related to the patient’s cultural level, economic status, age, and the occupation engaged in and other factors. Patients with high knowledge level or medical workers who have cancer tend to have a series of associations about bad prognosis, resulting in excessive psychological burden; patients with lower cultural level and less knowledge about cancer have a lighter psychological burden than the former; elderly patients have a sense of senility and think that death is a law of nature and a kind of transcendence, so their psychological reaction is lighter; and middle-aged and young patients are the backbone of the workforce and the pillars of the family, with a sense of responsibility and career development. On the other hand, young and middle-aged patients are both the backbone of their work and the pillars of their families, and their sense of responsibility and sense of career drive them to have more worries and concerns, so their psychological reaction is heavier. Cancer and psychotherapy: Psychotherapy is the use of human psychological activities to produce positive effects on the physiological and biochemical processes in the body, prompting the patient to develop towards healing. From the above, we can see that cancer is a kind of physical and mental disease, and we should raise the awareness of the significance of psychotherapy in the treatment of tumor patients, so as to improve the patient’s confidence, generate cheerful and joyful mood and optimistic and positive spirit, and then improve the immune function and disease-resistant ability of human body, and through adjustment, make the functions of various tissues and cells in the body return to normal, and the various organs tend to be coordinated with each other again. It should be pointed out that psychotherapy is multifaceted, multi-level, and requires the cooperation of health care personnel, patients’ families and patients, and it is impossible to accomplish it by a single party. It is impossible to accomplish it alone. Moreover, before psychotherapy, the patient’s cultural level, living habits, disease changes, thoughts and emotions as well as family environment should be fully evaluated, and appropriate psychotherapy should be chosen according to the patient’s cultural level, character traits and psychological characteristics, which should be differentiated according to the individual. Psychotherapy is only one aspect of comprehensive treatment for cancer, and it should be coordinated with other treatments to promote each other. 1.Health education: when patients can not fully understand their own diseases, they can produce anxiety and even have doubts about the treatment. Therefore, educating patients about relevant medical knowledge, providing general knowledge of cancer diagnosis and treatment, knowledge of cancer prevention, how to face cancer, etc., and distributing pamphlets about knowledge of the disease can help patients know more about themselves and improve their ability to adapt to the social environment. Eventually, help patients to reduce the sense of helplessness, relieve anxiety, depression level and life stress. Richardson et al. 94 cases of leukemia patients on allopurinol and prednisone chemotherapy drug adherence to health education interventions, the results show that the intervention group can significantly improve the patient’s adherence to allopurinol and so on, prolonging the survival period of cancer patients. Behavioral training: Behavioral training can help cancer patients reduce psychological stress and physical complications, and the intervention techniques include progressive muscle relaxation, hypnosis, deep breathing, biofeedback, active relaxation and guided imagery. Behavioral training can reduce the side effects of chemotherapy and general distress in cancer patients.Gruber found that the immune function of cancer patients was significantly improved by subjecting them to imagery and relaxation training. Moreover, the patient’s internal control in the psychological state increased, and the immune and emotional changes became parallel to the use of relaxation and imagination techniques. Individual psychotherapy: Individual psychotherapy based on empathy and understanding can alleviate the distress and frustration of cancer patients after knowing the diagnosis. Through general psychotherapy or psychological counseling, the negative emotions of patients can be quickly alleviated, and they can more actively cherish their limited life. It should be pointed out that some cancer patients who cannot receive organic treatment for some reasons are in greater need of psychological help. 4. Collective intervention: Organized psychological support group activities for cancer patients to carry out discussions among cancer patients on diagnosis and treatment of diseases, rehabilitation, death and dying, as well as interpersonal communication and family communication. It enables patients to form cohesion within the group, support each other, share distress, self-declare, and receive guidance from relevant medical personnel.Berglund et al. used the group intervention method to provide rehabilitation guidance to 98 patients, and found that the experimental group showed significant improvement in physical training, physiological strength, human imagery, and sleep, which showed that the group intervention had a lot of benefits for the patients. Therefore, organized psychosociological interventions can provide cancer patients with the greatest possible psychological support and serve as a buffer cushion in the process of mental stress, which can reduce the degree of mental stress, relieve patients of the psychological pain of anxiety, fear and depression that often exists, and contribute to the recovery of patients, and may even prolong the survival period of cancer patients. In addition, at the same time of psychological treatment for tumor patients, it should be soberly realized that the key to tumor treatment is early prevention, therefore, it is also necessary to carry out pre-cancer preventive psychological intervention for normal people. It is the responsibility of medical personnel to educate cancer medical knowledge through various channels, publicize the latest progress of cancer research in a timely manner, and remind people that as long as they can achieve early detection, early diagnosis and early treatment, cancer is also a curable disease, and there is no need for them to have a serious fear of it. In conclusion, the relationship between psychology and oncology is extremely close, whether it is from the occurrence of tumor, development or the end can be elaborated and solved from the perspective of psychology, with the establishment of new medical model, the psychological factor is an important force, the negative factors can contribute to the onset of cancer, while positive psychological factors can prevent cancer, prolong the survival period of cancer patients, and even cure cancer.