ABSTRACT
It would also be wrong to assume that every cell in a tumour behaves similarly. The daughter cells of a dividing cell are identical genetically to the parent cell and are said to be a clone (clonal expansion). However, tumour cells are also prone to develop genetic instability, which results in some cells developing further abnormalities, hence resulting in the formation of multiple subclones. These may have certain survival advantages, e.g. they may have enhanced angiogenic, invasive or metastatic capabilities. This is referred to as tumour heterogeneity and it is important to consider when planning treatments because it means that some tumour cells may respond differently to particular chemotherapeutic agents. This is rather analogous
The behaviour of a tumour can be considered under a number of headings covering how fast it will grow, whether it is likely to metastasise, which sites are affected, and what symptoms and complications the patient is likely to have.
