Treatment of cancer harboring mutations in the TP53 gene and/or post-translational modifications in the p53 protein. The present invention relates to the use of viruses belonging to the family Parvoviridae, genus Protoparvovirus, or combinations of such viruses with chemotherapy drugs, in the treatment of cancer. In particular the cancer is characterized by showing mutations in the TP53 gene and/or post-translational modifications in the p53 protein.