Book contents
- Frontmatter
- Contents
- Acknowledgements
- Foreword
- Introduction
- 1 Lessons from epidemiology
- 2 Causes of cancer
- 3 Signalling in normal cells
- 4 ‘Cancer genes’: mutations and cancer development
- 5 What is a tumour?
- 6 Cancer signalling networks
- 7 The future of cancer prevention, diagnosis and treatment
- 8 The future of cancer in the post-genomic era
- Appendix A Tumour grading and staging
- Appendix B Targets of specific anti-cancer drugs
- Appendix C Classes of major oncoproteins
- Appendix D Major tumour suppressor genes
- Appendix E Ten major cancers at a glance
- Glossary and abbreviations
- Bibliography
- Index
- Plate Section
2 - Causes of cancer
Published online by Cambridge University Press: 05 February 2013
- Frontmatter
- Contents
- Acknowledgements
- Foreword
- Introduction
- 1 Lessons from epidemiology
- 2 Causes of cancer
- 3 Signalling in normal cells
- 4 ‘Cancer genes’: mutations and cancer development
- 5 What is a tumour?
- 6 Cancer signalling networks
- 7 The future of cancer prevention, diagnosis and treatment
- 8 The future of cancer in the post-genomic era
- Appendix A Tumour grading and staging
- Appendix B Targets of specific anti-cancer drugs
- Appendix C Classes of major oncoproteins
- Appendix D Major tumour suppressor genes
- Appendix E Ten major cancers at a glance
- Glossary and abbreviations
- Bibliography
- Index
- Plate Section
Summary
The major causes of cancer fall into two categories: those over which we have some control and the rest. The latter includes radiation from the Earth that has been a background to human evolution and about which we can do nothing, although we could take more effective steps to limit the accumulation of radon in houses in regions where there is high, localised emission of the gas. The factors that we can control also fall into two groups: those exerting major effects for which the epidemiological evidence is overwhelming and those for which the data are inconclusive and therefore controversial. Of the former, the most familiar is the use of tobacco, which is responsible for 90% of lung tumours. By contrast, there are a number of prominent agents that may have weak tumour-promoting effects. For these the epidemiology is generally unpersuasive and direct experimental evidence has not been forthcoming, as exemplified by the continuing debate over the risks associated with the use of mobile phones. The two most effective measures we could take that would reduce the global cancer burden by at least one third would be to abolish the use of tobacco and to limit the consumption of red meat.
Introduction
In this chapter we’ll look at the major external factors that have been incriminated as causes of cancer. Several of these – radiation, tobacco and alcohol – are so well known that, rather than repeating the basic statistical evidence, we’ll say a little about the mechanism and other aspects of their involvement. For magnetic fields, however, which have been the subject of much media publicity, cause and effect remains unproven and it’s interesting to consider why it has been so difficult to come up with a clear answer about a connection. In some respects the matter of what we eat has been equally intractable. Defining a ‘good diet’ is easy, but pinning down precisely what is ‘bad’ has turned out to be tricky and we’ll say a little about the difficulties associated with large-scale epidemiological studies. It turns out to be a bit like the chap who is said to have eaten 25,000 ‘Big Macs’: the worst of his problem is likely to be the fruit and vegetables he’s missed out on rather than the polar bear’s weight of fat he’s eaten.
- Type
- Chapter
- Information
- Introduction to Cancer Biology , pp. 20 - 43Publisher: Cambridge University PressPrint publication year: 2012