I. Definition and content of genetic counseling Although different authors have different ways of expression, the basic content is similar. Genetic counseling is a process of information exchange or education, which is a series of discussions, advice and recommendations between a counselor and a patient with a genetic disorder or his or her relatives (counselee or consultant, client) about the cause of the disease, the mode of inheritance, the risk of developing the disease (or risk) and the measures that can be taken to prevent and treat the disease, in which correct An accurate and detailed family history of cancer is the basis of the correct risk assessment and further laboratory tests should be performed if needed. During the whole counseling process, we should keep explaining the questions and correcting the incorrect views in time. Therefore, it is very necessary to keep the confidentiality of the patient and to properly integrate psychological counseling into genetic counseling. Theoretical basis 1. Molecular cellular level: In terms of pathogenesis, cancer is a genetic and epigenetic disease of somatic cells. In the multi-stage pathological process of cancer, the core biological events are the accumulation of mutations and heritable expression changes of oncogenes and tumor suppressor genes, resulting in the selective expansion of cells with survival advantage and higher malignant potential, and the successive initiation and evolution of tumors when the immunosurveillance system fails to kill or suppress them, eventually forming fatal metastatic cancer. The genetic and epigenetic specific alterations of oncogenes and tumor suppressor genes provide the theoretical basis for the evaluation of cancer in high-risk individuals, early diagnosis, prognosis and monitoring of cancer patients, etc.; 2. Individual and population level: at the population level most patients’ cancers are not hereditary; cancers with obvious family history and mainly determined by genetic factors account for about 5% of all cancers, due to the large population base in China. On the other hand, the proportion of hereditary carcinomas can be higher in some common cancers, such as 10%-20% for colorectal cancer, nearly 10% for breast cancer, and up to 40% for some rare tumors such as retinoblastoma. Most of the high-risk genetic and familial cancer syndromes have been identified to be caused by germline mutations or epimutations of the above cancer-related genes, which have been mostly sequenced, localized, and tested, providing a reliable method for early assessment of the respective cancer risk of family members with a family history of cancer, and then appropriate preventive measures can be taken to reduce cancer incidence and mortality. More than 80% of cancers in the population are the result of the interaction between genetics and environment, i.e., genetics determines individual susceptibility and environment determines what kind of susceptible individuals develop cancer, so that different individuals have different sensitivity to carcinogenic agents (e.g., smoking). In recent years, our institute has established a variety of methods to detect genetic susceptibility, which provides further possibilities to identify a small number of people who are susceptible to specific carcinogenic agents. 3. The genotype of susceptibility determines only the possibility of developing cancer: whether the genotype of genetic susceptibility to tumor is high-risk or low-risk, it determines only the possibility of developing cancer in an individual, at what age or whether cancer will eventually form, and is also influenced by the environment, individual immunity, nutritional status and interaction with other genes, which provides the possibility of prevention, intervention and early diagnosis. In this way, if high-risk individuals can be identified, appropriate preventive and early diagnostic measures can benefit the counselors. 4.Modern medical model: The current medical model is in transition. The modern medical (biopsychosocial medical) model believes that cancer is a psychosomatic disease, and bad emotions and mental trauma are closely related to the occurrence of cancer; on the other hand, cancer cells produced under the action of various carcinogenic factors can be recognized by the human immune monitoring system and further killed or inhibited to prevent the occurrence of cancer; while psychosocial factors can Psychosocial factors can influence the occurrence and evolution of cancer by affecting the immune, neurohumoral and other functions and balance of the body. Proper genetic counseling can relieve the negative psychological pressure, adjust the balance of mind and body, and help mobilize the body’s own anti-cancer and anti-cancer potential. The significance and benefits of genetic counseling With the improvement of people’s living standard, they are increasingly concerned about their own health care. Since tumor death accounts for about 1/4 of all causes of death and the possibility of multiple deaths from cancer in a family increases, a considerable number of relatives of cancer patients in real life are very concerned about whether tumor can be inherited and hope to understand their own risk of cancer and its impact on their offspring, at this time, through tumor genetic counseling, it can help the inquirers as follows Knowledge of genetics, medical, epidemiological and psychological backgrounds; for family members with non-familial cancer, unnecessary mental burden can be reduced. 2. To confirm the family history of cancer, estimate the risk of cancer, and screen high-risk individuals through various genetic tests, so as to provide the possibility of focused and targeted prevention. 3.Mental burden of non-genetic cancer family members can be excluded. 4.Comprehensive analysis is conducted to determine the cancer risk of the counselor, and counseling techniques are applied to prevent excessive psychological stress in high-risk counselors, while providing advice on psychological adjustment, rational lifestyle (such as smoking, alcohol consumption, etc.), nutrition, prevention and early diagnosis, which is expected to prevent and delay the occurrence of cancer, provide effective etiological and clinical medical prevention, and improve the quality of life of the counselor. 5.Assessing the risk of cancer in individuals can help in marriage selection, improving the quality of offspring and the quality of human gene pool. Genetic counseling procedure 1. Fill out the questionnaire in detail and truthfully, including general information, lifestyle, dietary habits, environmental and psychosocial factors, etc. Understand the existing cancer risk factors and provide partial basis for counseling recommendations; 2. Understand and confirm the cancer incidence in the family in detail, draw the family tree; speculate the mode of inheritance and determine the risk of cancer in relatives; 3. Brief introduction of relevant background knowledge; genetic counseling according to family cancer risk and personal concerns; analysis, discussion and correction of incorrect perceptions, combined with psychological counseling to minimize the counselor’s anxiety and panic psychological pressure; and scientific advice on cancer prevention, such as lifestyle, freedom from pollution and health care decisions, according to the counselor’s specific situation. 5. Issue a written report and keep the test results confidential. V. Minimum criteria for referral or consultation 1. The same patient or his close relatives suffer from two or more uncommon malignant tumors, such as brain tumors and sarcomas, etc. 2.Malignant tumors associated with familial (hereditary) cancer syndrome such as retinoblastoma, neurofibroma, stained dry skin disease, Blooms syndrome, etc.; 3.Common malignant tumors ① 2 or more close relatives have the same type or related types of cancer such as breast/ovarian/colorectal/prostate/endometrial cancer, etc.; ② Close relatives (parents, siblings) diagnosed before the age of 40 The above common cancers.