Cancer Cell Division: How Cancer Cells Grow and Spread

Your body runs a remarkable operation - millions of cells dividing, replacing, and renewing themselves every single day. It's how wounds heal, how you grow, and how your body keeps itself going.

Cell division, in that sense, is one of life's most essential processes. But occasionally, the instructions that govern this process get corrupted, and a single rogue cell begins to multiply in ways it shouldn't.

That's where cancer cell division begins, and that's where the story of cancer truly starts. In this blog, we'll walk you through how cell division and cancer are connected, what derails the process, and what modern medicine can do about it.

What is cancer cell division?

Every cell in your body knows when to divide and when to stop; it's a finely tuned process that keeps your tissues healthy and functioning.

What is cancer cell division? It's when that control breaks down.

Certain cells accumulate mutations in the DNA sequences that regulate growth, causing them to divide continuously without a pause. Unlike normal cells, they don't respond to the chemical signals that would ordinarily slow or halt division.

Over time, these cells accumulate, forming masses that invade surrounding tissue and disrupt the body's function. These masses can turn cancerous if left unchecked.

The cancer cell division process

Every healthy cell passes through a series of tightly controlled stages, collectively called the cell cycle. Cancer disrupts this cycle at multiple points. Here's how the cancer cell division process unfolds:

1. 1. DNA mutation occurs: Damage to a cell's DNA can be triggered by cancer risk factors such as tobacco, UV radiation, certain viruses, or inherited gene faults. Most of the time, the body repairs this damage. When it doesn't, a mutation takes hold.
2. 2. Regulatory genes are affected: Mutations in proto-oncogenes can turn them into oncogenes that drive constant cell growth. At the same time, tumour suppressor genes (the cell's natural brakes) can be switched off entirely.
3. 3. Cell cycle checkpoints fail: Healthy cells have built-in checkpoints that catch errors before division proceeds. In cancer cell division, these checkpoints are bypassed, and the cell divides regardless of whether its DNA is intact.
4. 4. Uncontrolled division begins: With no functional brakes, the cell divides continuously. Each new daughter cell carries the same faulty mutations, repeating the cycle indefinitely.
5. 5. Tumour forms: Accumulating mutated cells form a mass, but not every tumour is cancer. Benign tumours stay localised and don't spread. It's the malignant ones that do, and a malignant neoplasm is precisely that. This is the key difference between a tumour and cancer in clinical terms.
6. 6. Metastasis occurs: Malignant cells can eventually break away, enter the bloodstream or lymphatic system, and establish new tumours elsewhere.

What separates normal cell division from cancer cell division

Healthy cells follow a strict, step-by-step process - dividing only when needed and stopping when the job is done. Cancer cells follow no such rules.

How normal cells divide

Normal cell division, known as mitosis, is a remarkably orderly process:

• •G1 Phase:
  The cell grows and prepares, checking whether conditions are right to proceed.
• •S Phase:
  DNA is copied, ensuring each new cell receives a complete, accurate set of genetic instructions.
• •G2 Phase:
  The cell double-checks for any DNA copying errors before moving forward.
• •Mitosis:
  The cell splits into two identical, healthy daughter cells.
• •Checkpoints:
  At every stage, built-in checkpoints verify that all is well. If damage is detected, the division pauses for repair.
• •Apoptosis:
  If a cell is too damaged to repair, it self-destructs through a process called apoptosis. It is the body's way of removing problem cells before they cause harm.

How cancer cells divide

Cell division in cancer cells takes a very different path. Here's where things go wrong:

• •Growth signals get stuck on:
  In healthy cells, growth signals switch on and off as needed. A genetic mutation cancer can cause these signals to stay permanently active, pushing the cell to divide nonstop.
• •Tumour suppressor genes fail:
  Genes like TP53 and BRCA normally put the brakes on excessive division. When mutated, these brakes stop working entirely.
• •Checkpoints are ignored:
  Unlike normal cells, cancer cells bypass the checkpoints that would otherwise catch and correct errors.
• •Apoptosis is switched off:
  Cancer cells develop the ability to evade self-destruction, allowing damaged, dysfunctional cells to survive and keep multiplying.
• •Cancer uncontrolled cell division:
  With every safeguard dismantled, cells divide without limit.

How is cell division related to cancer?

Type of cell division in cancer cells

The type of cell division in cancer is actually a corruption of the same mechanism healthy cells use. Knowing about which type of cell division occurs in cancer cells helps clarify why it's so difficult to control.

Here's what makes normal cell division vs cancer cell division different in practice:

It is worth noting that in rare cases, cancer cell division can exhibit asymmetric division - producing daughter cells with differing properties, some of which may be more aggressive or treatment-resistant than others. This variation is partly what makes certain cancers harder to treat as they progress.

Can cancer cell division be stopped or slowed?

Yes, this is where modern medicine has made remarkable strides.

Whether cancer cell division can be stopped depends on many factors, but well-established treatments do exist that directly target it.

Here's how the main treatment approaches tackle the problem:

• •Chemotherapy:
  Works by interfering with the cell division process directly. It targets rapidly dividing cells and prevents them from replicating.
• •Targeted therapy:
  Unlike chemotherapy, targeted therapy homes in on specific proteins or gene mutations driving cancer cell division. It blocks the signals that tell cancer cells to keep growing.
• •Radiation therapy:
  Uses high-energy rays to damage the DNA inside cancer cells, making it impossible for them to divide further. It's often used to shrink tumours before surgery or eliminate remaining cells afterwards.
• •Immunotherapy:
  Equips the body's own immune system to recognise and destroy cancer cells - including those actively dividing. It has transformed outcomes, particularly in carcinoma types such as melanoma and lung cancer.
• •Hormone therapy:
  Relevant in cancers fuelled by hormones, such as certain breast and prostate cancers. This treatment cuts off the hormonal signals that drive division, effectively slowing tumour growth.

Early action is the best response to cancer cell division

Normal cells divide in a controlled fashion - they grow, they stop, and they follow the body's instructions. Cancer cells don't. They divide without pause, ignore every signal to stop, and accumulate into masses that affect the body's normal functioning.

That's the fundamental difference.

However, when caught early, cancer cell division can be interrupted, managed, and in many cases, stopped altogether through treatments like chemotherapy, targeted therapy, and immunotherapy.