FAMILIAL ASSOCIATIONS, SURVEILLANCE AND PREVENTION
Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal of all major cancers. The typically, an affected person will live 6 – 12 months from the time of diagnosis and the 5-year survival rate is 4 %. Surgery offers the only chance for cure but only about 20 percent of affected persons are staged to be respectable at diagnosis and only about 20 percent of those going to surgery have resections of all detectable cancer. PDA has been shown to develop from accumulated genetic mutations progressing through hyperplasia, dysplasia, high-grade dysplasia, and on to invasive carcinoma similar to the adenoma-carcinoma sequence of colorectal neoplasms. These premalignant lesions are termed pancreatic intra-epithelial neoplasia (PanIN). The only definitively identified environmental risk factor is cigarette smoking which doubles a persons risk for pancreatic cancer. Chronic pancreatitis for two or more years imparts a relative risk of 17 fold for PDA. About 10 % PDA cases are familial and may occur in defined syndromes with known genetic mutations or in families with an autosomal dominant pattern of transmission. Defined syndromes include hereditary pancreatitis, cystic fibrosis, BRCA-2, hereditary non-polyposis colorectal cancer, familial adenomatous polyposis, Li Fraumeni, Peutz-Jeghers, ataxia-telangiectasia, and familial atypical mole melanoma. A mutated gene locus has been identified in at least one family not affected by known syndromes. Surveillance is recommended with endoscopic ultrasound followed by ERCP if abnormalities are found. Patients with confirmed abnormalities on ERCP are counseled to have distal pancreatectomy and subsequent total pancreatectomy if diffuse PanIN lesions are present in the resected specimen. Newer imaging technologies are under study as are serum and pancreatic juice biological markers using micro-array, proteomic, and genetic technologies. Chemoprevention appears biologically feasible in laboratory studies but epidemiological data are discouraging.
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