What’s Cancer?

At last, you are going to understand what is cancer.


The 4th of February is The World Day Against Cancer. Today I want to tell you, as easily and quickly as possible what is cancer.


Our body is made up of cells, that similar to any other living beings, are born, grow, reproduce and die. They are something similar to this: 



In their DNA, their instructions manual, it is written that, if they start acting weird or aging they should commit suicide. Yes, you read it right. They are programmed so that, if they don’t work as they should, they kill themselves to avoid diseases for us.


Well, cancer cells don’t die.

Besides, they reproduce at an uncontrolled rate, faster than normal. So, new cancer cells keep appearing all the time.


And, what happens next? 

Since they don’t die and reproduce faster than normal, they start using a lot of space. They take up space from the cells around them. That’s how a tumour starts to form.



But it’s not only space that they take from neighbouring cells but also food and oxygen


Maybe you have heard that there are benign and malignant tumours. What’s the difference between them? 

Benign tumours don’t move from the place where they appear and malignant tumours do. Malignant tumours have the ability to attack nearby areas (infiltration) and to travel to other parts of the body, which is known as metastasis. 


If the tumour is malignant, then we are talking about cancer


Since we have many types of cells distributed throughout the body, each with its own characteristics and specific function, there are many different types of cancer. Cancerous cells can appear anywhere in the body. That’s why each type of cancer behaves differently, and certain treatments work better than others to fight it.


But, why does all this happen? Why do cells go crazy?

Because DNA, their instructions manual, gets damaged. In this guide, there may be missing words, or they may be rearranged… In other words, cancer arises from mutations in the genetic code of cells.


In summary: Cancer is a group of diseases (because there are many different types of cancer) that occurs when cells reproduce faster than normal, don’t die naturally, and are capable of attacking other parts of the body.




Fundación Josep Carreras

NIH National Cancer Institute (USA)

American Cancer Society

Mayo Clinic




NIH National Cancer Institute (USA)

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