As you may know, your body is made up of trillions of little units called cells. Everyone starts out life as one single cell, which grows and divides to make a fully grown human. But even in adults, cells have to keep growing and dividing to replace cells that die (which happens a lot during the natural course of things) and to repair damage, for example if you cut yourself.
So, what’s that got to do with cancer? Well, basically, if cells start growing and dividing too much and they take over, that’s cancer. One of the reasons cancer is so hard to treat is that it’s the person’s own cells, so it can be difficult to find drugs or treatments that will kill the cancer cells but not harm the normal cells.
Hi Clarissa. Mariam has already given a really good answer to this question and she is an expert in why cells multiply out of control the way they do in cancer. Maybe she will be able to tell you more about that in a live chat?
When the cells start to ‘take over’ like Mariam described and there is no control over how many of the cells there are they can form tumours. They can also spread to places in the body that they don’t belong and can cause damage to important organs like the liver, the lungs or the brain.
Cancer is a word used to describe lots of different diseases which have a single thing in common: cells growing and dividing without control. Our cells divide normally all the time, to replace cells that have been damaged, or to heal wounds, or when we are growing. Cancer is caused when the DNA get damaged in such a way that the cell no longer listens to the signals which tell it when it should divide, and it just keeps growing and dividing. Usually this forms a tumour.
Imagine the body as a big team formed by millions of cells. To work well, every cell has to be a team player, listening to what the other cells say and adjusting its behaviour depending on what the other cells do. One of the most important things to coordinate is how many times a cell can divide and, when it gets old, to kills itself, because the number of players (the cells) in a body has to be perfectly regulated.
Now imagine a cell that has gone mad and doesn’t want to play with the others anymore and doesn’t want to respect the rules: that is a cancer cell.
A cancer cell doesn’t respect anymore the signals that say when to divide and when to kill itself, so not only it divides indefinitely growing as a tumour and invading the body, but also it escapes all the mechanisms to lead to its death.
The different tumours depend on where the first cell has gone mad, so if the cell was in the skin, then there will be a skin cancer, if in the colon, then it’s colon cancer and so on.