CDKN2A Germline Mutations in Familial Pancreatic Cancer

ObjectiveTo evaluate the prevalence of mutations in the CDKN2A gene encoding p16INK4a and p14ARF in familial pancreatic cancer (FPC). Summary Background DataThe genetic basis of FPC is still widely unknown. Recently, it has been shown that germline mutations in the p16INK4a tumor suppressor gene can predispose to pancreatic cancer. The presence of p14ARF germline mutations has yet not been determined in this setting. MethodsEighteen families with at least two first-degree relatives with histologically confirmed pancreatic cancer and five families with at least one patient with pancreatic cancer and another first-degree relative with malignant melanoma of the German National Case Collection for Familial Pancreatic Cancer were analyzed for CDKN2A germline mutations including p16INK4a and p14ARF by direct DNA sequencing. All participating family members were genetically counseled and evaluated by a three-generation pedigree. ResultsNone of 18 FPC families without malignant melanoma revealed p16INK4a mutations, compared to 2 of 5 families with pancreatic cancer and melanoma. Truncating p16INK4a germline mutations Q50X and E119X were identified in the affected patients of pancreatic cancer plus melanoma families. None of the 23 families revealed p14ARF germline mutations. ConclusionsCDKN2A germline mutations are rare in FPC families. However, these data provide further evidence for a pancreatic cancer–melanoma syndrome associated with CDKN2A germline mutations affecting p16INK4a. Thus, all members of families with combined occurrence of pancreatic cancer and melanoma should be counseled and offered screening for p16INK4a mutations to identify high-risk family members who should be enrolled in a clinical screening program.