Cells are the building blocks of our body, and each of us is made up of several trillion of the little guys. Within each cell, DNA controls what it does – acting like an instruction book. But should this DNA get damaged then there is a chance a tumour (or cancer) can develop.
Every day we encounter radiation and chemicals (both natural and man-made) that can cause damage our DNA. Sometimes this can cause the ‘words’ of the instruction book to get messed up – resulting in the cell functioning abnormally. Usually, the occasional faulty cell isn’t a problem; if a cell doesn’t work properly it just dies, and a new one takes it place.
But occasionally DNA damage – or ‘mutations’ – can be particularly dangerous, making a cell change what it does and start growing and multiplying uncontrollably. There are all sorts of ways for DNA damage to make this happen. For example, a cell may be instructed to reproduce itself far more often than it should. Or, a malfunctioning cell might gain the ability to survive much longer than usual. Or a mutated cell could develop the ability to resist the body’s own ‘waste disposal’ defences against rogue cells.
This is why cancer is so hard to fight. The body isn’t being taken hostage by a foreign invader like a virus or bacterial infection; the threat comes from within. Sometimes, it seems, you really are your own worst enemy.
Image source: Amy Dame on flickr