Hereditary cancer syndromes of the skin

Melanoma genetics: an update on risk-associated genes

The past 15 years have seen rapid advances in both our understanding of hereditary melanoma genetics and the technologies that enable scientists to make discoveries. Despite great efforts by many groups worldwide, other high-risk melanoma loci besides CDKN2A still remain elusive. A panel of polymorphisms that appears to confer low-to-moderate risk for melanoma has been assembled through functional and genome-wide association studies. The goal of personalized melanoma risk prediction is within our reach, although true clinical use has yet to be established.

Management of familial melanoma and nonmelanoma skin cancer syndromes

The clinical manifestations of hereditary skin cancer syndromes depend upon the interplay between environmental and genetic factors. Familial melanoma occurs in the setting of hereditary susceptibility, with a complex phenotype of early age of onset, multiple atypical moles, multiple primary melanomas, multiple melanomas in the family, and in some instances pancreatic cancer. Identification of individuals who may have a hereditary susceptibility for the development of melanoma is essential to provide an opportunity for primary prevention, and to target high-risk groups for early diagnosis and treatment. Consequently, the surgeon as one of the primary caregivers should be familiar with hereditary skin cancer syndromes and their pathogenesis, diagnosis, management, and surveillance recommendations. This article discusses a practical approach for some of the issues likely encountered by the surgeon in the management of familial melanoma and non-melanoma skin cancer.

The effect of having an affected parent or sibling on invasive and in situ skin cancer risk in Sweden

Studies suggest that skin cancer aggregates within families; however, the risk of skin cancer associated with having an affected sibling or parent by subtype, tumor site, and age at diagnosis has not been established. The 2006 update of the Swedish Family-Cancer Database was used to calculate standardized incidence ratios (SIRs), representing the ratio of cancer risk among individuals with affected parents or siblings to the general population. Risk of invasive squamous cell skin cancer for individuals with an affected sibling or parent was increased between two- and three-fold compared with that in the general population. For in situ skin tumors, increased SIRs of 1.95-4.30 for squamous cell, Bowen's disease, and actinic keratosis were observed for individuals with affected siblings or parents, and SIRs were generally higher for tumors at sun-exposed versus covered sites. Finally, SIRs for in situ and invasive squamous cell skin cancer increased by increasing number of parental tumors (P< or =0.01). In conclusion, having an affected sibling or parent was associated with an increased risk of skin cancer of varied subtypes compared with that in the general population, and for some subtypes, these familial risks were increased for tumors at sun-exposed sites or by an increasing number of parental tumors.

Lessons from the skin--cutaneous features of familial cancer

As the molecular basis of disease continues to be elucidated, familial cancer syndromes, which consist of a range of neoplastic and non-neoplastic features, are emerging. The usual pathway of referral to a genetics clinic or familial cancer centre is via an oncologist, when high-risk features that suggest a possible hereditary basis for the presenting cancer are recognised. Traditionally, these high-risk features include more than two family members with similar cancers over two or more generations, a young age of onset, and more than one synchronous or metachronous tumour. These features are effective in ascertaining a substantial proportion of families with hereditary breast and ovarian cancer due to a BRCA mutation, or the more common bowel-cancer predisposition syndromes, such as hereditary non-polyposis colon cancer and familial adenomatous polyposis. However, there are a range of familial cancer syndromes that are not easily detected and that can remain undiagnosed when history and examination are not extended to include non-malignant features. The identification of cutaneous signs associated with rare familial-cancer syndromes provides individuals and their families with the opportunity to undertake early surveillance for malignant and non-malignant complications that might in time be shown to improve outcomes.