2.2.7 Cancer

• Describe how tumours (and cancers) form

  ● Growth of abnormal cells

  ● Due to changes in cells that lead to uncontrolled growth and division
• Describe the differences between benign

  and malignant tumours

  ● Malignant tumours are cancerous; benign tumours are not

  ● Malignant tumours invade neighbouring tissues; benign tumours do not

  ● Malignant tumours spread to different parts of the body in the blood so

  can form secondary tumours; benign tumours stay in one place, usually

  contained within a membrane

  ● Malignant usually grow faster than benign tumours
• Describe how a tumour can spread to different parts of the body

  ● Cells break off and travel in the blood

  ● Forming secondary tumours
• What are the two types of risk factors for cancer?

  ● Lifestyle risk factors eg. smoking, carcinogens, ionising radiation, some viruses

  ● Genetic risk factors
• why is this statement wrong?

  “All tumours are cancerous.”

  Only malignant tumours are cancerous, so can spread
• why is this statement wrong?

  “Cancer is caused by cells growing too

  fast.”

  Cancer cells often do grow faster, but the key point is that their

  growth and division is uncontrolled.
• Suggest two reasons

  why the survival rates

  for all cancers have

  increased. (2)

  ● Improved treatment / drugs

  ● Earlier diagnosis

  ● More / improved cancer screening

  ● Improved patient knowledge of risk factors