The goal of this study was to determine the prevalence of PALB2 mutations in a population of BRCA1/BRCA2 negative breast cancer patients selected from either a personal or family history of pancreatic cancer.
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.
PALB2 mutation analysis was performed in 110 non-BRCA1/2 cancer patients: (a) 53 ovarian cancer patients from female breast-and/or ovarian cancer families; (b) 45 breast cancer patients with a first or second degree relative with pancreatic cancer; and (c) 12 male breast cancer patients from female breast cancer families.
The PALB2509_510delGA and 172_175delTTGT mutations combined were seen in 2 (0.52%) unselected cases of PaCa and in 8 (0.20%) of 4,000 controls (OR: 2.61, p = 0.49).
The prevalence rate of PALB2 mutations in a non-BRCA1/2 breast cancer population specifically selected for a family history of pancreatic cancer does not appear to be significantly increased compared to that observed in other breast cancer populations studied thus far.
Results Thirty-three (3.9%; 95% CI, 3.0% to 5.8%) of 854 patients with pancreatic cancer had a deleterious germline mutation, 31 (3.5%) of which affected known familial pancreatic cancer susceptibility genes: BRCA2 (12 patients), ATM (10 patients), BRCA1 (3 patients), PALB2 (2 patients), MLH1 (2 patients), CDKN2A (1 patient), and TP53 (1 patient).
Biallelic mutations in PALB2 cause FA (Fanconi's anaemia) subtype FA-N, a devastating inherited disorder marked by developmental abnormalities, bone marrow failure and childhood cancer susceptibility, whereas monoallelic mutations predispose to breast, ovarian and pancreatic cancer.
This work suggests that inactivation of the PALB2 gene is a determinant of response to DNA damage in pancreatic cancer and a new target for personalizing cancer treatment.
In addition, no significant associations were observed between 11 PALB2 tagging SNPs and melanoma risk in 23 melanoma-prone families with CDKN2A mutations or the subset of 11 families with PC or PC-related CDKN2A mutations.
The proband carrier of c.3047T>C (p.F1016S) showed two breast cancer cases, two ovarian cancer cases and one pancreatic cancer in mother's family. c.3047T>C (p.F1016S) and c.*146A>G should be considered PALB2 UVs even though the genotype-phenotype correlation for these variants remains still unclear.
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.
These consist of high penetrance genes including BRCA2 or PALB2, to more common genetic variation associated with a modest increase risk of pancreatic cancer such as genetic variation at the ABO blood group locus.
It subsequently became clear that PALB2 was another Fanconi anemia (FA) gene (FANCN), and that monoallelic PALB2 mutations are associated with increased risk of breast and pancreatic cancer.
Since its identification as a BRCA2 interacting partner, PALB2 has emerged as a pivotal tumor suppressor protein associated to hereditary cancer susceptibility to breast and pancreatic cancers.