I am grateful to the following people for their constructive comments

on drafts of the chapters: Dr Peter Anderson (chapter 3); Drs David

Forman and Tim Key and Ms Jean King (chapter 4); Dr Jane Melia

(chapter 5); Professors Jocelyn Chamberlain and Alan Horwich and

Dr Ian Jacobs (chapter 8); Professor Jocelyn Chamberlain and Dr

Jack Cuzick (chapter 9); and Drs David Forman and Lesley Walker

and Professor Bruce Ponder (chapter 10). I acknowledge the Cancer

Research Campaign, which provides long term support for my work.

In particular I thank Jane Toms, who has helped me to provide up to

date facts and figures for this book, and Jean King for her support

and advice. Many of the facts presented in this book can be found in

the Cancer Research Campaign's series of factsheets. Further infor-

mation relating to these factsheets can be obtained from the Cancer

Research Campaign Education Department, 6-10 Cambridge

Terrace, London NW1 4JL.