Family History and Genetic Factors
Most people with skin cancer to not have a history of skin cancer in their family. Yet for some people this is the case. Approximately ten percent of melanoma patients for example have a parent, sibling, or child with the disease. This does not necessarily mean that they have defective genes, it could be due to very similar risk factors (like skin type, behavior, tendency to freckle and form moles, sunburn history, etc.). Yet there are families where several members contract melanoma. Studies of these families have led to the discovery of the role of p16 role in formation of melanoma. The p16 gene is a regulatory gene, which prevents the proliferation of cells. If this gene is damaged it no longer prevents the multiplication of normal cells causing a tumor to form. This gene may be inherited in a defective form, causing an increased risk of certain forms of cancer (e.g. melanoma) in people with such cells in their bodies.
This is not the only cancer-causing genetic disorder that can be inherited. Examples of other inherited disorders that may increase the risk of getting skin cancer are:p>
Xeroderma Pigmentosum (XP)
a very rare inherited defect that occurs in 1 out of every 250,000 people in the US. In healthy people the skin is able to repair UV-induced damage of the skin to a certain extent. People who have XP carry a defect of that repair mechanism. Therefore UV radiation can easily produce severe DNA damage that may lead to malignant melanoma or other forms of skin cancer.
Nevoid Basal Cell Carcinoma Syndrome (NBCCS)
Familial Melanoma or Hereditary Dysplastic Nevus Syndrome