[PALB2, a major susceptibility gene for breast cancer]

Abstract

Objectives: About 5% of breast cancers are linked to an inherited predisposition, the two most known susceptibility genes being BRCA1 and BRCA2. Recently, new susceptibility genes, including PALB2, have been identified. The risk of breast cancer associated with a deleterious mutation of PALB2, the age of onset of these cancers, their prognosis and associated cancers have so far been the subject of controversy. Our objective was to clarify these different questions from an updated review of the literature.

Methods: The analyzed articles were taken from the PUBMED database between January 2008 and December 2015. The keywords used were "breast cancer" and "PALB2".

Results: Women with PALB2 mutations have a higher risk than the general population of developing breast cancer. The relative risk is significant, varying according to the different studies between 3,4 (IC 95%: 2,4-5,9) and 9,47 (IC 95%: 5,72-14,39). The different mutations as well as environmental and geographical factors should be taking into account when interpreting these results. There is currently no proven link between a PALB2 mutation and the occurrence of ovarian or pancreas cancer.

Conclusion: PALB2 must be considered as a high-penetrance breast cancer predisposing gene. Women with a PALB2 mutation face an increased risk of triple negative breast cancer and higher risk of death from breast cancer.

Keywords: Breast cancer; Cancer du sein; Mutation; Oncogenetics; Oncogénétique; PALB2.