Pre-existing patient: III generation 9, female, 66 years old, medical worker. She had intermittent microscopic hematuria for more than three years and had undergone several ultrasound, CT, and urinary exfoliative cytopathology examinations which were normal. One week before admission, ultrasound revealed a one-centimeter mass on the left wall of the bladder, and cystoscopy revealed a one-centimeter papillary mass on the outside of the left ureteral orifice, without a tip, which was electrically excised. The pathology was reported as metastatic cell carcinoma. 3 of the first generation of the mother’s family were male, living in Zhenjiang, Jiangsu Province, who died of breast cancer, and the age of onset was unknown. The mother’s family generation II9 was male, lived in Changzhou, died of lung cancer, age of onset was about 60 years old. Precedent’s mother generation II8 did not have the disease. Preceding father’s family I generation 1 is male, lives in Shanghai, died of colon cancer, age of onset unknown. Father’s family generation I2 was female, lived in Shanghai, died of liver cancer, age of onset was about 70 years old. Father’s family generation II5 is male, lives in Baoding, died of stomach cancer, age of onset unknown. Father’s family II generation 6 is male, lives in Guizhou, died of lung cancer, age of onset unknown. The father’s family II generation 3 was female, lived in Shanghai, did not have the disease, but his two daughters both had female cancer, III generation 4 lived in Shanghai, had breast cancer, age of onset 60, and III generation 2 lived in Shanghai, died of ovarian cancer, age of onset 32. The father of the preclear II generation7 did not have the disease. The older brother of the preclear, generation III6, lived in Zhenjiang, Jiangsu Province, and was fond of deep-fried foods in his life and died of liver cancer at the age of 66. His son Ⅳ generation1 lived in Shanghai and died of bladder cancer at the age of 49. The second sister of the predeceased, III generation 8, lived in Xinjiang and suffered from breast cancer at the age of 80. The third sister of the preclear III generation 11 lived in Suzhou, liked to eat salt-drowned food, suffered from stomach cancer, age of onset 63 years. The cancer family refers to a family with a high incidence of malignant tumors (about 20%), an early age of onset, usually inherited in an autosomal dominant manner, and a high incidence of certain tumors (e.g., adenocarcinoma), which Lynch summarized as the “cancer family syndrome”. A cancer family (family G) was reported, and after five surveys over 70 years (starting in 1895), with some branches reaching the seventh generation, a total of 95 cancer patients were found among 842 descendants, with colon (48) and endometrial (18) adenocarcinomas being the majority. Among these 95 patients, 13 had multiple tumors and 19 had cancer before the age of 40; 72 of the 95 patients had one of the two parents with cancer, 47 males and 48 females each, close to 1:1, consistent with autosomal dominant inheritance. The incidence rate was 38%, but the age of onset was late, 7 cases were above 60 years old, 1 case was 49 years old, 1 case was 32 years old, and the age of onset was unknown in 4 cases. Familial carcinoma refers to multiple members of a family suffering from the same type of tumor; for example, 12-25% of colon cancer patients have a family history of bowel cancer. Many common tumors (e.g. breast cancer, bowel cancer, stomach cancer, etc.) are usually disseminated, but some patients have a significant family history. In addition, the incidence rate among first-degree relatives of patients is usually 3 to 4 times higher than that of the general population. The mode of inheritance of this type of cancer, although not well understood, suggests the phenomenon of familial aggregation of some tumors or an increased susceptibility of family members to these tumors. This case reports a total of 6 people in two cancer families with intestinal, gastric and breast cancers, respectively. Many facts listed above indicate the existence of genetic factors in tumor development, so tumors can be considered as diseases caused by genetic chromosomal abnormalities. Some of these hereditary tumors are transmitted according to the classical Mendelian way, but in more cases what is inherited is only the susceptibility to tumors, i.e. susceptibility genes, and if somatic mutations occur again in the individual susceptible state, the mutant cells are easily transformed into tumor cells.