A large new study of twins has found that having a twin sibling diagnosed with cancer poses an excess risk for the other twin to develop any form of cancer. Among the 23 different types of cancer studied, an excess familial risk was seen for almost all of the cancers, including common cancers such as breast and prostate cancer, but also more rare cancers such as testicular cancer, head and neck cancer, melanoma, ovarian and stomach cancer.
More...