It has been discovered that proliferation of inflammatory breast cancer (IBC) cells can be inhibited by inhibiting the function of histone deacetylase 6 (HDAC6). Advantageously, such functional inhibition is accomplished by administration of a therapeutically effective dose of Ricolinostat (ACY1215) to a patient in whom IBC cells are proliferating. In further accordance with the invention, it is possible to predict the responsiveness of a particular patient with cancer (particularly breast cancer, and most specifically inflammatory breast cancer) to administration of an HDSC6 inhibitor. This is accomplished by acquiring mRNA gene expression profiles of a biopsy sample of the patient's tumor tissue. The processed gene expression profiles of the patient are then integrated into a gene expression database and are then normalized across the entire database. Then, the normalized gene expression profiles are input to an algorithm. An HDAC6 signature characteristic of the patient's tumor type is also input to the algorithm, and the output of the algorithm makes it possible to evaluate the responsiveness of the patient's tumor to administration of HDAC6 inhibitor. Advantageously, the gene expression profiles are acquired using standard RNA-Seq technology or microarray and the gene expression database is The Cancer Genome Atlas ("TCGA").Il a été découvert qu'il est possible d'inhiber la prolifération de cellules du cancer du sein inflammatoire (IBC) par inhibition de la fonction de l'histone-désacétylase 6 (HDAC6). De manière avantageuse, cette inhibition fonctionnelle s'obtient par une administration d'une dose thérapeutiquement efficace de Ricolinostat (ACY1215) à un patient chez lequel a été observée une prolifération des cellules d'IBC. En outre, selon l'invention, il est possible de prédire la réactivité d'un patient particulier atteint d'un cancer (en particulier d'un cancer du sein, et notamment d'un cancer du sein inflammatoire) à l'administration d'un inhibiteur de
