Medical applications of artificial neural networks (ANNs) have touched on a variety of areas such as anaesthesiology, radiology, cardiology, psychiatry, and neurology. ANNs are parallel information-processing structures that attempt to emulate certain performance characteristics of the biological neural system. From the studies of neural application in cancer research, it is clear that ANNs have an impact on cancer research from a number of different angles. Although the process of cancer management may be somewhat deterministic, in that surgeons and pathologists can confidently ascertain the existence and extent of spread, such determination is usually reached through biopsies or axillary assessment at the expense of patient morbidity and health service resources. Reliable assessment of the progression of a tumour is essential for proper treatment. This has prompted researchers to search for prognostic factors, simple tests or measurements that could yield information about the biological features of the disease in relation to the state of its progression.