Early Detection and Prevention

There are several things about hereditary cancer that are different from sporadic cancers. These features help in identifying families that may have a hereditary cancer syndrome.

Early age of cancer onset: Hereditary cancer often occurs 15 – 20 years earlier than the average age of onset in the general population.
A particular pattern of several different cancers in the family: An example is the combination of cancer of the breast and ovary in HBOC.
An excess of multiple primary cancers: The hypothetical pedigree depicts this as well as bilateral cancer in paired organs such as the breast.
Mendelian pattern of inheritance: Most hereditary cancer syndromes behave in what we refer to as an “autosomal dominant” mode of genetic transmission. Autosomal means that male as well as females will have equal risk for inheriting the harmful mutation and for passing it on in our hypothetical pedigree, even though they are not affected with the syndrome cancers, the males have an equal chance of inheriting the cancer predisposing gene. They can then transmit the gene to their sons and daughters. Dominant means that only one copy of the mutation has to be transmitted for the individual to be increased risk and to transmit that risk to their offspring. Since there would be one normal gene and one mutated gene in that particular pair of genes, the chance of passing on the mutation is 50% and the chance of passing on the normal gene is 50%.

Cancer stigmata: Certain hereditary cancer syndromes may be associated with physical findings. An example is a disorder described by Creighton researchers several decades ago know as the familial atypical multiple mole melanoma (FAMMM) syndrome. FAMMM is an autosomal dominant predisposition to malignant melanoma. In addition to the increased risk of melanoma, affected family members may have multiple pigmented moles (sometimes in the hundreds) and fewer atypical or “funny looking” moles. The stigmata of FAMMM can be seen on the back of the individual shown in the photo below:

The Individual has multiple normal moles dispersed over the back, as well as numerous atypical moles, which are unevenly pigmented with varying shades of brown and with notched borders. Affected members of families with FAMMM can develop cancer in these atypical moles or even on the normal skin that does not have any moles. Melanoma mortality can be significantly reduced within these families with early identification of malignant melanoma, therefore affected members should have surveillance of their skin every four months by a physician.

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