How Does Cancer Start to Form?

Dr.Arun Giri, 3 mins read

All cancer develops when cells grow, and divide abnormally. This creates a mass of abnormal cells, which combine to form a cancerous tumour. If not addressed at the initial stage, the tumour can grow and affect other body parts or organs as well, which can be fatal.      

An adult human body has over 30 trillion cells. These cells work as building blocks, which group together to form tissues and organs. Each cell has a genetic content that guides it throughout its life. It tells cells when to grow, work, divide, and die. 

Till the time these genes send proper instructions to cells and they follow them, we stay healthy. Each cell has a different job. But they all have a nucleus in the centre, which is the control centre. This nucleus contains chromosomes made up of genes. Genes contain a long string of DNA (deoxyribonucleic acid), which are coded messages that instruct the cells. 

A change in or damage to DNA can mutate the genes inside them. Mutated genes can send improper information to cells. As a result, cells can grow and divide abnormally, resulting in a lump called a tumour. A tumour can be benign (non-cancerous) and malignant (cancerous).

How Does Mutation Occur? 

Mutations in cells are not an uncommon thing. It happens daily but our cells are very good at repairing those changes. But when the cells grow too fast, repairing them becomes impossible. 

Mutations can happen by chance, genetic factors or foreign objects. By chance means changes during cell division. Foreign objects mean things coming from outside the body, such as tobacco smoke or industrial toxins. Genetic factors mean inheriting faulty genes from parents. 

How Are Cancerous Cells Different?

Cancerous cells are different from normal cells in many ways. First, cancerous cells grow abnormally and uncontrollably. Cancerous cells don’t develop into mature cells that can perform their specific jobs. They avoid the immune system and don’t stick together properly as they should. They damage our own organs and spread to other body parts through the blood and lymphatic system.  

How Are Cancerous Cells Similar to Normal Cells?

Although they are different from normal cells, they also need a blood supply for oxygen and nutrients like the normal one. For that reason, they take essential supplies from nearby healthy cells. 

How Do Tumours Grow & Spread?

As the tumour grows, its requirements also increase. The tumour then develops new blood vessels for extra nutrients. This is called angiogenesis. That’s why the tumour grows much bigger. 

As the tumour becomes bigger, it pushes aside its nearby healthy cells. Cancerous cells also make enzymes that break down normal cells. Cancerous cells that grow into nearby cells are invasive or local invasion cancer.

Cancer cells also make their way to the bloodstream, from where they circulate to other body parts. This process is called metastasis.