Explainer: What is cancer, how does cancer start and how does cancer spread in the body, know everything | How Cancer Starts, Grows and Spreads

Cancer begins when cells in the body grow and spread uncontrollably, forming a tumor.

How does cancer start in the body?

Our body is made up of innumerable cells and the genes present inside the nucleus of each cell tell it when to grow, work, divide and die. When our cells follow all these instructions properly, we remain healthy. But when there is any change or damage to our DNA, the genes can mutate. Mutated genes do not work properly. Due to this, cells can grow in an uncontrolled manner, which can lead to cancer.

What is cancer, how does cancer start? How does cancer spread in the body? How cancer starts, grows and spreads How does cancer start in the body?

Our body's cells normally grow and divide only when the body needs them to, such as to replace aging or damaged cells. Cancer begins when the body's cells grow and spread uncontrollably, forming a tumor. Cancer occurs when cells do not die normally and the genes that control their growth change.

How does cancer grow?

Gene mutations in cancer cells can prevent the cell from following normal instructions, causing the cell to grow uncontrollably or not die when it should. Cancer can grow in the body because cancer cells work differently than normal cells.

Cancer cells are different from normal cells because:

• They divide uncontrollably.
• These are immature and do not develop into mature cells.
• These evade the immune system.
• They ignore signals that tell them to stop dividing or that tell them to die.
• These do not stick together well and can spread to other parts of the body through the blood or lymphatic system.
• These can damage tissues and organs.

As cancer cells divide, a tumor begins to develop. Cancer cells have the same needs as normal cells. They also need oxygen and nutrients to grow and survive. A small tumor can grow easily because it gets oxygen and nutrients from nearby blood vessels.

But as a tumour grows, it needs more blood to deliver oxygen and other nutrients to the cancer cells. So the cancer cells send signals to the tumour to make new blood vessels. This is called angiogenesis and is one of the reasons why tumours grow and get bigger.

How does cancer spread in the body?

As a tumor grows, cancer cells can spread into nearby tissues and structures, putting pressure on normal tissue around the tumor. Cancer cells also make enzymes that break down normal cells and tissues as they grow. Cancer that grows into nearby tissues is called local invasion or invasive cancer.

Cancer can also spread to other parts of the body from where it started. This process is called metastasis.

Where can cancer spread?

Cancer can spread anywhere in the body, but it is most likely to spread to the lymph nodes, bones, brain, liver and lungs.

Why does cancer sometimes come back?

Cancer sometimes comes back after treatment. In fact, if even one cancer cell remains in the body, it can grow and divide into many cells and form a new tumor. This is why doctors sometimes do a second treatment immediately after the first treatment, such as giving chemotherapy after surgery. This is called adjuvant therapy. The purpose of this therapy is to reduce the chances of cancer coming back again.

Sometimes in some cases, the treatment stops working, which means that the cancer cells are no longer being destroyed. So cancer that had previously shrunk or disappeared due to treatment begins to grow again.

(Disclaimer: This content including advice provides general information only. It is in no way a substitute for qualified medical opinion. Always consult a specialist or your doctor for more information. Newscrab does not claim responsibility for this information.)

PC: NDTVINDIA