If there is one disease that the world is afraid of, it is cancer. Sadly, there is no cure available yet and the research towards curing and preventing it is still ongoing. However, even when there is no cure (with no side effects), there is plenty of literature at the disposal explaining what causes cancer, how it starts and how it grows.
So, if you have always been curious to know how cancer starts and spreads, consider this your easy-peasy guide to understanding cancer.
First things first, what is cancer? And how is it different from a tumour?
We are going to spare you the technicalities and explain it in simple words.
Your body is made of a gazillion cells that form into tissues and organs. Just like life, every cell is meant to be born, die and get replaced by new cells. Moreover, every cell comprises a nucleus, and the nucleus consists of genes that dictate it to grow, divide and die. A healthy body would follow the process thoroughly, where every day the cells will grow, die and be replaced by new cells.
However, sometimes when things go wrong, these cells will have the instructions mixed up and would grow abnormally and uncontrollably (when they should die). When these cells grow uncontrollably, it can cause a tumour.
Mind you, cancers and tumours are not the same thing even though they are used interchangeably.
A tumour is the abnormal growth of cells caused by genetic, internal or environmental abnormalities. Cancer, on the other hand, is a disease that is caused by the abnormal growth of cells. A tumour can be benign, meaning it cannot spread to other parts. Cancer, however, is always malignant; meaning it can spread to other parts and infect the other cells in different locations of the body. A tumour that is malignant, is called cancerous and leads to cancer.
Picking up where we left off…
Now, coming back to cancer, how it starts and grows.
Cell division takes place when there is a need, i.e. when the cells need to be replaced, or during ageing. Cancer cells are normal cells first before they start changing. Let’s take an illustration to understand it better.
Imagine a normal cell to be an obedient student who would listen to their teacher’s instructions devotedly. However, sometimes owing to certain reasons (such as trauma, stress or bad company), this student begins to rebel and do the opposite of what is being instructed. The once-upon-a-time obedient child becomes a spoilt one.
So, what was the result here? It began harming the class environment (which in this context, is the human body). Now after wreaking havoc in the former place, the student decides to move further away and gets shifted to the other section. The result? The same havoc but in a different locality. Only this time, he spoiled other students (damaging other cells in other organs of the body)
Shifting back to the biological jargon…
In the context of the human body, this cancerous cell is the disobedient child. A cancerous cell didn’t follow the instructions of the genes and grew and divided itself when it should have stopped in the first place. It formed into a tumour and travelled to other parts of the body through blood. When it went to the other location, it started spreading, causing cancer in the different areas.
It is also important to remember that the body doesn’t differentiate between normal cells and cancerous cells. Consequently, it feeds the cancerous cells (small) the same nutrients it feeds to the normal cells (ironic of our body to fuel the cells that would only harm itself, pretty self-sabotaging, right?).
Hence, with these nutrients, the cancer cells grow. However, as these cells grow, they require more oxygen and nutrients. It is at this moment the tumour begins to make new blood vessels for itself (angiogenesis) and this is how the cancer spreads to other parts of the body.
You may also wonder, what went wrong? Why didn’t the cell follow the instructions? What caused this rebellious behaviour?
Being disobedient, in the biological jargon, simply means being uncontrollable. A normal cell becomes cancerous when it doesn’t respond in the manner it should. So, what causes this rebellious behaviour? The answer is mutation. Biologically speaking, a mutation is a change and alteration in the DNA sequence.
To keep things simple, you can consider mutation as a change, let it be a behavioural change. This behavioural change can be because of a lot of factors. Most commonly, it is genetic. Just as they say, an apple doesn’t fall far from the tree. If somebody is genetically predisposed to have cancerous cells, they are more likely to form cancer cells, i.e., cells that would mutate in the future.
But apart from genetics, there are other factors that can make cells cancerous, i.e. mutate. These factors can be smoking, exposure to UV radiation and toxic chemicals, or a high-fat diet.
There, you have it – Cancer explained in layman’s terms. From the intricate interplay of genetic mutations to the diverse array of factors that fuel its growth, our understanding of cancer’s origins and behaviours has grown exponentially. Armed with this knowledge, researchers and medical practitioners are better equipped to develop targeted therapies, innovative treatment strategies, and personalized approaches that aim to halt cancer’s advance and improve patient outcomes. As the fight against cancer presses on, collaboration between scientists, healthcare professionals, and advocates remains pivotal, holding the promise of a future where the devastating impact of cancer can be mitigated, ultimately offering renewed hope to individuals and families worldwide.