In this study, we show that in an area with low melanoma incidence, CDKN2A germline mutations in patients with melanoma and personal or family history of pancreatic cancer are mainly present in the setting of familial or multiple melanoma cases.
In addition, CDKN2A mutated MPM cases had worse survival compared with both cases with familial (HR 3.0, 95% CI 1.3-8.1) and sporadic wild-type MPM (HR 2.63, 95% CI 1.3-5.4).
We now report on a proposita presenting with multiple biopsy-proven cutaneous neurofibromas and a solitary spinal neurofibroma found to have a deletion of 14 nucleotides in exon 2 of CDKN2A, providing further evidence that p14, p16, and/or ANRIL are specifically involved in the pathogenesis of neurofibromas as a feature of the familial atypical multiple malignant melanoma spectrum.
Most of the genes listed are responsible for various well-defined cancer syndromes, such as CDKN2A (familial atypical mole-multiple melanoma, FAMMM), the mismatch repair genes (Lynch Syndrome), TP53 (Li-Fraumeni syndrome), APC (familial adenomatous polyposis), and BRCA2 (breast-ovarian familial cancer), where PC is part of the cancer spectrum of the disease.
Patients in whom a melanoma was diagnosed during specific follow up of high-risk individuals carrying CDKN2A mutations (with familial or personal history of previous melanoma) were included in this study.
Occurrence of childhood tumors in hereditary cancer syndromes such as BRCA1/2 associated breast and ovarian cancer, DNA-mismatch repair (MMR) genes associated hereditary non polyposis colorectal cancer and CDKN2A associated familial malignant melanoma are very little studied.
The level of expression was equally distributed between the familial (NF1) and sporadic cases, although it should be noted that the 2 cases with p16(INK4A) expression were sporadic.
A proportion of melanoma-prone individuals in both familial and non-familial contexts has been shown to carry inactivating mutations in either CDKN2A or, rarely, CDK4.
Rb phosphorylation is mediated by cyclin-dependent kinases (CDKs), whose activity is enhanced by cyclins and inhibited by CDK inhibitors. p16(INK4A) is a member of a family of inhibitors specific for CDK4 and CDK6. p16(INK4A) is deleted and inactivated in a wide variety of human malignancies, including familial melanomas and pancreatic carcinoma syndromes, indicating that it is an authentic human tumor suppressor.
We analyzed families with two or more cases of melanoma for germline mutations in CDKN2A and CDK4 to elucidate the contribution of these gene defects to familial malignant melanoma and to the occurrence of other cancer types.
A mutation in the 5' untranslated region (UTR) of CDKN2A generates a novel upstream initiation codon that abrogates expression of p16, and a common polymorphism in the 3' UTR is associated with increasing familial risk of melanoma.
Inherited mutations in the CDKN2A/INK4a/MTS1 tumour suppressor gene on chromosome 9p21 are associated with familial predisposition to melanoma and other tumour types.
Germline mutations in CDKN2A occur in both familial and sporadic MPM and further studies are required to determine the value of analysis of this gene in melanoma surveillance.