Higher Human Biology Unit 1 – Section 1 (e) Cancer Higher Human Biology Unit 1 – Section 1 (e)

Learning Intention To discuss what somatic cells are and cells that arise from the differentiation of somatic cells.

Cancer cells Cancer cells have many characteristics that make them different from normal cells: Cancer cells continue to reproduce to produce a mass of abnormal cells (a primary tumour). Cancer Cells do not respond to normal regulatory signals that would instruct them to stop dividing when necessary. Cancer cells lose the molecules on their surface that would normally hold them in place and can therefore be detached from their neighbours, causing the cells to spread (secondary tumour). To see a very nice overview explaining what cancer is click here Skin cancer cells (melanoma)

Benign or Malignant Tumours can be either benign or malignant. Benign tumours aren't cancer. Malignant ones are. Benign tumours grow only in one place. Benign tumours cannot spread or invade other parts of your body. Even so, they can be dangerous if they press on vital organs, such as your brain.

10 Cancer Facts from the World Health Organisation Warning – You will not be asked details from below but we thought this information is important and links to stem cells as possible treatments Fact 1 There are more than 100 types of cancers; any part of the body can be affected. Fact 2 In 2008, 7.6 million people died of cancer - 13% of all deaths worldwide Fact 3 About 70% of all cancer deaths occur in low- and middle-income countries. Fact 4 Worldwide, the 5 most common types of cancer that kill men are (in order of frequency): lung, stomach, liver, colorectal and oesophagus. Fact 5 Worldwide, the 5 most common types of cancer that kill women are (in the order of frequency): breast, lung, stomach, colorectal and cervical. In many developing countries, cervical cancer is the most common cancer.

Fact 6 Tobacco use is the single largest preventable cause of cancer in the world causing 22% of cancer deaths Fact 7 One fifth of all cancers worldwide are caused by a chronic infection, for example human papillomavirus (HPV) causes cervical cancer and hepatitis B virus (HBV) causes liver cancer Fact 8 Cancers of major public health relevance such as breast, cervical and colorectal cancer can be cured if detected early and treated adequately Fact 9 All patients in need of pain relief could be helped if current knowledge about pain control and palliative care were applied. Fact 10 More than 30% of cancer could be prevented, mainly by not using tobacco, having a healthy diet, being physically active and moderating the use of alcohol. In developing countries up to 20% of cancer deaths could be prevented by immunization against the infection of HBV and HPV.

HPV – environmental factors Certain strains of the human papilloma virus (HPV) have been shown to cause cervical cancer. The routine immunisation programme in Scotland is for girls aged 12 and 13 (S2). There is also a one-off, three-year catch-up programme for older girls.

Cancer Cancer cells divide excessively to produce a mass of abnormal cells (called a tumour). They do not respond to regulatory signals that would instruct them to stop dividing when necessary. They may fail to attach to each other, called malignant tumours. This means they can spread throughout the body, forming secondary tumours. Nanotechnology Video Clip

Questions & Answers How are cancer cells different from other cells? Cancer Cells do not respond to normal regulatory signals that would instruct them to stop dividing when necessary. What is a tumour? Is a mass ( lump ) of cancerous cells How does a cancer spread? They become detached from their neighbours and move through the body What is the difference between a malignant tumour and a benign tumour? Benign tumours cannot spread or invade other parts of your body but malignant ones spread into secondary tumours Give one way in which stem cells are being studied as a form of cancer treatment? New treatment aims to kill the damaged stem cells which give rise to all the cell types in a tumour

Extra thinking…………. The risk of getting cancer can be reduced by changes in lifestyle. For ten tips on how to reduce your risk of getting cancer clink here For an overview on how stem cells are being investigated as a way of studying and treating cancer click here

Learning Outcomes Cancer cells divide excessively to produce a mass of abnormal cells (a tumour) that do not respond to regulatory signals and may fail to attach to each other. If the cancer cells fail to attach to each other they can spread through the body to form secondary tumours.