PALB2 Mutation in Hereditary Breast and Ovarian Cancer
Posted: Wednesday, January 9, 2019
The discovery of the role of BRCA mutations in hereditary breast and ovarian cancer syndrome was a breakthrough in cancer genetics. However, a significant percentage of cases remain that cannot be explained by BRCA mutations. In a study conducted in Spain and published in The Breast, researchers discovered that PALB2 mutations are present in approximately 1% of Spanish patients with BRCA-negative hereditary disease.
“PALB2 screening should be encouraged in women from [hereditary breast and ovarian cancer syndrome] families to implement genetic counselling in the case of a strong family cancer history and possible selection to receive PARP inhibitors,” stated Mar Infante, PhD, of the Institute of Genetics and Molecular Biology at the University of Valladolid, Spain, and colleagues. Because PALB2 cooperates with BRCA genes in DNA damage response, germline mutations in PALB2 can compromise genome stability, predisposing carriers to cancer through the accumulation of DNA defects.
The study included 160 high-risk BRCA-negative patients and 320 controls; the high-risk group included patients with either ovarian or breast cancer and first-degree relatives with ovarian cancer. A total of 16 PALB2 variants were identified in the high-risk group, including 4 predicted splicing disruption variants and 4 rare missense variants.
Interestingly, the researchers discovered a frameshift mutation in an early onset cancer family. The mutation was identified in a woman diagnosed at 33 years of age with an ovarian adenocarcinoma and her sister who developed breast cancer at the age of 36 years but was not present in nonaffected family members. “The early onset cancer in the carriers supports the idea that PALB2 confers a substantial risk of [hereditary breast and ovarian cancer syndrome] in this family,” concluded the investigators.
Disclosure: The study authors’ disclosure information may be found at thebreastonline.com.