Understanding Cancer: Causes and Risk Factors

Question
what is the leading cause of cancer?is it hereditary?

Answer
To a large part that is still unknown. Hereditary factors often play a role but there are also other factors like mutations, chemical effects, virus infections, radiation damage etc. An example of chemical effect is cigarette smoke and lung cancer. Of virus infection is human papilloma virus infection and cancer of the uterine cervix. And of radiation is sun light induced skin cancer. A hereditary example may be some colon cancers - probably not all.