Question: How long has cancer been around for and why did it start?

Ee Lyn Lim answered on 18 Jun 2013:

Cancer has probably been around for as long as there has been multicellular life! Cancer in humans has been recorded as early as in Egyptian times, more than 5000 years ago. The name ‘cancer’ itself comes from the Greek and Latin words for ‘crab’ (remember the zodiac sign?), because people all those years ago thought a tumour, which is a lump with lots of blood vessels leading out of it, looked like a crab.

But it’s not just humans that can get cancer, lots of other living things get them too – dogs, mice, even fishes, even plants!! One of the most serious cases of cancer in animals is actually in Tasmanian Devils, which you can read about here: http://www.tassiedevil.com.au/tasdevil.nsf/The-Disease/979FEB5F116CE371CA2576CB0011A26E

So how did cancer start? Cancer begins when there are mutations in the DNA of a cell. DNA is kind of like a set of instructions that tell the cell how to behave – that’s why a bone cell stays in the bone, for example, and why you don’t suddenly grow an ear in the middle of your forehead. When DNA gets mutated, these instructions change, and sometimes it happens that they tell the cell to grow and multiply out of control – that’s why you get a lump of cells that’s called a tumour. Lots of factors can cause mutations in DNA, including UV rays, some harmful chemicals (cigarette smoke, for example), or virus infections. Even a perfectly healthy cell can get mutations out of nowhere, because DNA needs to be copied over every time a cell divides, and everyone makes mistakes – even cells! So any cell could possibly become an out-of-control cell, and if it’s part of a bigger organism it forms a tumour, and we call it cancer.