Cancer
What Is Cancer?
Cancer is a non-communicable disease caused by uncontrolled cell growth and division. This can lead to the formation of a tumour.
💡 Key Concept: Cancer occurs when cells divide uncontrollably, often due to mutations in genes that control the cell cycle.
Types of Tumours
Type | Description | Dangerous? |
Benign | Growth of abnormal cells in one place | Not cancerous, but may cause pressure on organs |
Malignant | Cancerous – cells invade other tissues | Yes – can spread through the blood |
💡 Malignant tumours are more dangerous as they can metastasise (spread to other parts of the body).
Causes of Cancer (Risk Factors)
Risk Factor | Type of Cancer Linked |
Smoking | Lung, throat, mouth, bladder |
Obesity | Bowel, kidney, liver |
UV exposure | Skin cancer |
Genetics | Some breast and ovarian cancers |
Alcohol | Liver and mouth cancer |
Radiation exposure | Increases mutation risk |
How Does Cancer Develop?
1️ A mutation occurs in a gene controlling cell division
2️ The cell begins to divide uncontrollably
3️ A tumour forms
4️ If malignant, cells can spread via the bloodstream or lymphatic system
Treatments for Cancer
Treatment | How It Works | Notes |
Surgery | Removes tumour | Best for localised cancers |
Radiotherapy | Uses radiation to kill cancer cells | Can damage healthy cells too |
Chemotherapy | Uses drugs to kill cancer cells or stop division | Affects healthy dividing cells (e.g. hair, gut lining) |
Targeted therapies | Block specific cancer-related molecules | Fewer side effects |
Questions
- What is cancer?
- What is the difference between benign and malignant tumours?
- Name two risk factors for developing cancer.
- What is metastasis?
- Give one way cancer can be treated.
Summary
- Cancer is caused by uncontrolled cell growth due to mutations.
- Tumours can be benign or malignant.
- Risk factors include lifestyle choices and genetics.
- Treatments include surgery, radiation, chemotherapy, and targeted therapies.