Chapter 7.2 Cancer

Question 1

What is the definition of a benign tumour?

Answer 1

A benign tumour is a tumour that does not invade its surrounding tissue or spread around the body.

Question 2

What is the definition of a malignant tumour?

Answer 2

A malignant tumour is a tumour that may invade its surrounding tissue or spread around the body. This tumour is often referred to as cancer.

Question 3

What are the causes of cancer?

Answer 3

• Genetic risk factors for some cancers
• Most cancers are a result of mutations - changes in genetic material.
• Chemicals such as asbestos and tar cause mutations that trigger the formation of tumours. These cancer-causing agents are called carcinogens
• Ionising radiation such as UV, can interrupt the normal cycle and cause tumours to form.
• 15% of human cancers are caused by virus infections. For example cervical cancer.

Question 4

What are treatments for cancer?

Answer 4

• Radiotherapy - cancer cells are destroyed by targeted doses of radiation. This stops mitosis in the cancer cells but can also damage healthy cells.
• Chemotherapy - chemicals are used to either stop the cancer cells dividing or to make them ‘self destruct’.

Question 5

How can lifestyle factors affect tumours?

Answer 5

The most common risk factors for cancer include aging, tobacco, sun exposure, radiation exposure, chemicals and other substances, some viruses and bacteria, certain hormones, family history of cancer, alcohol, poor diet, lack of physical activity, or being overweight.