Germline mutations of BRCA1 are also associated with ovarian cancer and mutations of BRCA2 are associated with an increased risk of male breast cancer, ovarian cancer, prostate cancer and pancreatic cancer.
Proportion of ovarian cancer was increased in the 5' portion of BRCA1, and presence of prostate or pancreatic cancer in a family was correlated with presence of ovarian cancer in BRCA2.
This article traces the historical aspects of hereditary cancer dealing with identification and ultimate molecular genetic confirmation of commonly occurring cancers, particularly of the colon in the case of familial adenomatous polyposis and its attenuated form, both due to the APC germline mutation; the Lynch syndrome due to mutations in mismatch repair genes, the most common of which were found to be MSH2, MLH1, and MSH6 germline mutations; the hereditary breast-ovarian cancer syndrome with BRCA1 and BRCA2 germline mutations; the Li-Fraumeni (SBLA) syndrome due to the p53 mutation; and the familial atypical multiple mole melanoma in association with pancreatic cancer due to the CDKN2A (p16) germline mutation.
Given the dismal prognosis of PC, with the only current hope for survival being through surgical extirpation of the pancreas prior to metastasis, it is prudent that we realize the potential predisposition toward PC via BRCA1, in the hope of early diagnosis and prevention.
Seven germline BRCA1 mutation carriers with pancreatic adenocarcinoma and nine patients with sporadic pancreatic cancer were identified from clinic- and population-based registries.
Our findings suggest that mutations in the BRCA1 gene are not highly, or even moderately, prevalent in families with a clustering of pancreatic cancer, including pancreatic cancer families who report a family history of breast and/or ovarian cancer.
Additionally, mean ages of diagnosis of pancreatic cancer in BRCA1/2 families differ significantly from the SEER mean (P = 0.0014 for BRCA1 and P = 0.011 for BRCA2 by unpaired t-test).
A clinical database review (2000-2009) identified 211 Ashkenazi Jewish (AJ) BC probands who 1) underwent BRCA1/2 mutation analysis by full gene sequencing or directed testing for Ashkenazi founder mutations (BRCA1: 185delAG and 5382insC; BRCA2: 6174delT) and 2) had a FH of PC in a first-, second-, or third-degree relative.
As it is well known that the prevalence of gene mutations varies between different populations, we studied the prevalence of PALB2 mutations in a Dutch cohort of non-BRCA1/2 familial PC (FPC) families and in non-BRCA1/2 familial BC (FBC) families with at least one PC case.
Germ-line mutations in PALB2 lead to a familial predisposition to breast and pancreatic cancer or to Fanconi Anemia subtype N. PALB2 performs its tumor suppressor role, at least in part, by supporting homologous recombination-type double strand break repair (HR-DSBR) through physical interactions with BRCA1, BRCA2, and RAD51.
The most important genes with variants increasing risk for pancreatic cancer include BRCA1, BRCA2, PALB2, ATM, CDKN2A, APC, MLH1, MSH2, MSH6, PMS2, PRSS1, and STK11.
However, a subset of pancreatic cancer is attributable to known inherited cancer predisposition syndromes, including several hereditary breast cancer genes (BRCA1, BRCA2, and PALB2), CDKN2A, hereditary pancreatitis, hereditary nonpolyposis colorectal cancer, and Peutz-Jeghers syndrome.
The SIR for all BRCA1/2 mutation carriers compared with the rates in the general population were elevated for pancreatic cancer [2.97 (95 % CI 1.83-4.29)] and breast cancer [16.44 (95 % CI 9.65-26.24)].