The present invention provides a method for treating or preventing cancer in a subject wherein the subject is identified as having a BRCA2-/- and/or PALB2-/- mutation comprising: a) obtaining a sample from a subject b) analyzing the sample for the presence of a BRCA2-/- and/or PALB2-/- mutation c) administering to the subject a therapeutically effective amount of an C1-C6 aldehyde or prodrug or derivative thereof when the analysis of the sample of b) indicates the subject has a BRCA2-/- and/or PALB2-/- mutation. In addition, the use of a pharmaceutical composition comprising a therapeutically effective amount of an C1-C6 aldehyde or prodrug or derivative thereof, and/or an aldehyde dehydrogenase inhibitor is also provided for treating cancer in a subject wherein the subject is identified as having a BRCA2 -/- and/or PALB2 -/- mutation. Also provided herein is an isolated human adenocarcinoma cell line genetically modified to have a biallelic disruption of the PALB2 gene, and methods for identifying a compound or small molecule that modulates a function of a cancer cell or population of cells genetically modified to have a biallelic disruption of the PALB2 gene are also provided.La présente invention concerne une méthode de traitement ou de prévention dun cancer chez un sujet, le sujet étant identifié comme ayant une mutation BRCA2-/- et/ou PALB2-/-, comprenant : a) lobtention dun échantillon provenant dun sujet b) lanalyse de léchantillon pour la présence dune mutation BRCA2-/- et/ou PALB2-/- c) ladministration au sujet dune quantité thérapeutiquement efficace dun aldéhyde en C1-C6 ou dun promédicament ou dun dérivé de celui-ci lorsque lanalyse de léchantillon de b) indique que le sujet a une mutation BRCA2-/- et/ou PALB2-/-. De plus, linvention concerne également lutilisation dune composition pharmaceutique comprenant une quantité thérapeutiquement efficace dun aldéhyde en C1-C6 ou dun promédicament ou dun dérivé de celui-ci, et/ou un inhibiteur daldéhyde déshydr
