Medical oncologists describe a cancer or likelihood of cancer as familial if a family genealogy shows, say, breast or ovarian cancer in female relatives. They would suspect a gene passed down but not know its identity. A hereditary cancer or likelihood of cancer is when a person is shown, by genetic testing, to carry a specific gene, such as BRCA1 or BRCA2, that has been linked to a much higher frequency of incidence of the cancer. Medical oncologists suggest that the distinction between familial and hereditary cancers will eventually be eliminated as the genes for the familial cancers are identified.
This view is complicated by:
a) the association with the identified gene “correspond[ing only] to a small increase in incidence of the trait” (see previous post in the series), perhaps because
b) the factors underlying the cancer may not be the same from one set of relatives to the next (previous post), and/or
c) “the information [about carrying a gene] might not translate into remedial action or not into action that is within the resources of the person and their community of care and support” (previous post).
(Introduction to this series of posts)