Phenotype Approach IDs Rare ATR Variants as Potential Male Breast Cancer Susceptibility Alleles

PRESS RELEASE - A new research paper was published in Oncotarget's Volume 14 on February 7, 2023, entitled, “The ‘extreme phenotype approach’ applied to male breast cancer allows the identification of rare variants of ATR as potential breast cancer susceptibility alleles.” In oncogenetics, some patients could be considered as “extreme phenotypes”, such as those with very early onset presentation or multiple primary malignancies, unusually high numbers of cancers of the same spectrum or rare cancer types in the same parental branch. For these cases, a genetic predisposition is very likely, but classical candidate gene panel analyses often, and frustratingly, remains negative. In this new study, researchers Martin Chevarin, Diana Alcantara, Juliette Albuisson, Marie-Agnès Collonge-Rame, Céline Populaire, Zohair Selmani, Amandine Baurand, Caroline Sawka, Geoffrey Bertolone, Patrick Callier, Yannis Duffourd, Philippe Jonveaux, Yves-Jean Bignon, Isabelle Coupier, François Cornelis, Christophe Cordier, Monique Mozelle-Nivoix, Jean-Baptiste Rivière, Paul Kuentz, Christel Thauvin, Romain Boidot, François Ghiringhelli, Marc O'Driscoll, Laurence Faivre, and Sophie Nambot from Université de Bourgogne, CHU Dijon Bourgogne, CHU Besançon, University of Sussex, Centre Georges François Leclerc, Université de Bourgogne-Franche Comté, Hôpitaux de Brabois, Centre Jean Perrin, ICM Val d’Aurel, Université Bordeaux, CHU de Bordeaux, CHRU de Strasbourg, and CHU-Reims used a combination of exome sequencing (ES), direct sequencing of Ataxia Telangiectasia and RAD3-related (ATR) in a replication cohort and prospective screening, followed by functional investigations, to report the identification of new candidate variants of ATR as predisposing to breast cancer (BC), including male breast cancer (MBC). “In the framework of the EX2TRICAN project, exploring unresolved extreme cancer phenotypes, we applied exome sequencing on rare familial cases with male breast cancer, identifying a novel pathogenic variant of ATR (p.Leu1808*).” ATR has already been suspected as being a predisposing gene to breast cancer in women. The researchers next identified 3 additional ATR variants in a cohort of both male and female with early onset and familial breast cancers (c.7762-2A>C; c.2078+1G>A; c.1A>G). Further molecular and cellular investigations showed impacts on transcripts for variants affecting splicing sites and reduction of ATR expression and phosphorylation of the ATR substrate CHEK1. This work further demonstrates the interest of an extended genetic analysis such as exome sequencing to identify very rare variants that can play a role in cancer predisposition in extreme phenotype cancer cases unexplained by classical cancer gene panels testing. “In conclusion, this work highlights the possible implication of ATR variants in male and female BC predisposition and shows the importance of extended genetic analysis in unsolved extreme phenotype cancer cases to identify rare alleles of biologically relevant candidate genes of cancer predisposition.” DOI: https://doi.org/10.18632/oncotarget.28358 Correspondence to: Sophie Nambot - sophie.nambot@chu-dijon.fr Keywords: male breast cancer, genetic predisposition to cancer, exome sequencing, ATR, extreme phenotype