How Does Cancer Develop?
Part of Cancer and Cell Division Control — GCSE Biology
This how it works covers How Does Cancer Develop? within Cancer and Cell Division Control for GCSE Biology. Cancer development, cell cycle control mechanisms, tumor formation, risk factors, prevention methods, and treatment approaches It is section 8 of 18 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 8 of 18
Practice
18 questions
Recall
22 flashcards
How Does Cancer Develop?
Cancer is a multi-step process that unfolds over time as mutations accumulate in specific genes that control cell division.
Every cell contains proto-oncogenes — genes that normally stimulate the cell to divide when needed. They also contain tumour suppressor genes that put the brakes on division and trigger cell death (apoptosis) when damage is detected.
When a carcinogen (such as UV radiation or tobacco smoke chemicals) damages DNA, a mutation may occur in one of these control genes. A single mutation is rarely enough to cause cancer. However, if mutations accumulate over time:
- A mutated proto-oncogene becomes an oncogene — it sends constant "divide now" signals, like an accelerator stuck to the floor.
- A mutated tumour suppressor gene stops working — the brakes fail and nothing stops division.
With both accelerators stuck on and brakes removed, the cell enters a cycle of uncontrolled mitosis. Each new cell inherits the same mutations, and the growing mass of abnormal cells forms a tumour. If malignant, cells may eventually break away and spread via blood or lymph — a process called metastasis.
Grade 7-9 point: Most cancers require mutations in several different genes. This is why cancer risk increases with age — there is simply more time for multiple mutations to accumulate.