The term ‘metastasize’ describes the spread of cancer beyond the original site of the cancer to other parts of the body. To understand how cancer metastasizes, it is helpful to review how cancer first occurs.
Cancer begins when normal kidney cells change, or mutate. These cancerous cells then begin to multiply at a much faster rate than normal cells would, and form a tumour.
Once a tumour is large enough, its cells begin to release a substance called vascular endothelial growth factor, or VEGF, which stimulates the surrounding blood vessels to grow. This process is referred to as angiogenesis. The increased blood supply enables the tumour to continue to grow, but also starts to carry tumour cells from the kidney throughout the rest of the circulatory system to other parts of the body, where new tumours may develop.
It is important to note that if a new tumour develops in a different area of the body – for example, in the lung – this is referred to as kidney cancer that has metastasized, not a new diagnosis of lung cancer.
Understanding the nature of kidney cancer, including how it metastasizes, helps to direct research into more effective treatments.
