Cancer Info

Root Causes of Cancer

Cancer begins when cell DNA is damaged and growth control is lost — here is what drives that process.

Understanding Cancer

What causes cancer at the root?

Cancer is not caused by one single event. It develops when genetic changes (mutations) allow cells to grow and divide without normal controls. Over time, these abnormal cells can form a tumour and invade nearby tissue.

The biological root

  • DNA damage — genes that control cell growth, repair and death stop working properly
  • Uncontrolled division — abnormal cells keep multiplying instead of stopping
  • Immune escape — the body fails to remove damaged cells early enough
  • Tumour formation — a mass of abnormal cells grows and may spread

What damages cell DNA?

Lifestyle exposures

Tobacco, alcohol, unhealthy diet, obesity and physical inactivity raise long-term cancer risk.

Environmental factors

Pollution, industrial chemicals, radiation and contaminated water can contribute to DNA damage.

Infections

Certain viruses and infections (such as HPV for cervical cancer) can trigger cancer-related changes.

Inherited factors

Some people inherit gene changes that increase susceptibility, though most cancers are not purely genetic.

Important to remember

Having a risk factor does not mean a person will definitely get cancer. Many cancers develop from a combination of causes over years. That is why prevention and early screening matter so much — they interrupt the process before cancer becomes advanced.