Sometimes a family will appear to have a hereditary cancer when what they really share is a common living or working environment that exposes them to things that can cause mutations. This is why a family history is an important part of your personal risk assessment.
Most cancers occur by chance. However, in some families, cancer occurs more often than can be expected to happen by chance.
Determining which of these families has cancer related to an inherited gene mutation is important, as the cancer risks for family members will be much higher than in the general population. These subgroups, or populations, may be organized in several ways:
Following along family lines:
- Multiple occurrences of the same type of cancer in your family
- Development of multiple cancers in an individual
- Previously identified mutations of certain cancer genes