遗传疾病,癌症 z-bo 2020-09-21 409

　　According to the results of this large study, approximately one-third of cancers are inherited. The highest family genetic risks include prostate cancer, breast cancer, lung cancer and bowel cancer. Scientists have found that if siblings get these cancers, the risk of other siblings getting the same cancer will increase by 33%. This is the largest and longest research in history to study the relationship between genetics and cancer. Studies have found that different cancers have different genetic risks. Among them, melanoma and testicular cancer are most closely related to heredity.

　　The overall research results are not surprising, but further confirm the earlier research results, that about 1/3 of cancer cases are caused by genetic defects, and most of the rest are attributed to so-called lifestyle factors, such as smoking, Diet and exercise.

　　Different types of cancer have different genetic risks

　　A research team led by Lorelei Mucci of the Harvard School of Public Health reported in the Journal of the American Medical Association that currently about 38% of kidney cancers, 31% of breast cancers, 27% of uterine cancers, 58% of melanomas, and 57% of prostate cancers Cancer and 39% of ovarian cancer are genetically related.

　　Researchers say that more than 8% of children with cancer have unexpected gene mutations in their families. These mutations not only put children at risk of cancer in the future, but also may mean that their parents, siblings, and siblings also have a very high risk of cancer. Memphis of Jude Children's Research Hospital believes that the results of the study not only use new methods to detect cancer risks in children and their families, but also may find better ways to treat them.

　　From 1943 to 2010, this study tracked more than 200,000 pairs of twins in Sweden, Norway, Denmark and Finland, tracking each person for an average of 32 years. This large-scale twin study allows scientists to assess the importance of genetic factors to cancer, and to assess the family's cancer risk by measuring the genetic similarities and differences between identical and fraternal twins. The genes of identical twins are exactly the same, while the genes of fraternal twins are only similar, so the difference in cancer risk between the two clearly points to genetic factors.

　　Mucci’s research team also found that 38% of identical twins and 26% of fraternal twins were diagnosed with cancer. When one of the twins is diagnosed with cancer, the risk of cancer in the other is significantly increased. The risk of fraternal twins is 37%, while the risk of identical twins is as high as 46%. Jacob Hjelmborg of the University of Southern Denmark said: “Due to the large scale of this study and the long tracking time, we can see the impact of key genes on many types of cancer.”

　　The genetic risk of testicular cancer is high. If a person's fraternal twin brother has testicular cancer, his risk of developing testicular cancer will increase 12 times. For identical twins, the risk of testicular cancer in one person and testicular cancer in the other is 28 times higher.

　　The investigation team also found that about 1% of people got melanoma, which is the deadliest form of skin cancer. If one of the fraternal twins has melanoma, the other has a 6% risk of melanoma, while for identical twins, the other has a 20% risk of melanoma.

　　The risk of prostate cancer and breast cancer may be due to their coexistence in the same uterus when they were young, and both are strongly affected by hormones, including those that affect fetal growth. Lung cancer is greatly affected by the environment, possibly because the twins’ smoking habits are mostly the same.

　　It should be noted that in the Nordic countries that participated in the study, cancer is the number one cause of death. In the United States and other developed countries, cancer is the second leading cause of death, after heart disease.