Genome-based versus gene-based theory of cancer: possible implications for clinical practice.

The current state in oncology research indicates that the attempts to explain such complex process as cancerogenesis by a single or several genetic mutations were not successful enough. On the other hand, chromosomal/genomic instability--almost universal features of malignant tumours which influence a global pattern of gene expression and, subsequently, many oncogenic pathways--were often disregarded and considered nonessential to clinical application. However, a new arising field of system biology including 'new forms' of genome diversity such as copy number variations (CNV) and high-throughput oncogene mutation profiling now reveal all the complexity of cancer and provide the final explanation of the oncogenic pathways, based on stochastic (onco)genomic variation rather than on (onco)genic concepts.