According to Joel Fuhrman, MD there are more scientific studies that show cancer is caused by diet than there is that it is caused by tobacco use.
The following foods have been implicated in causing cancer: animal protein, dairy, anything refined, sugar, salt ...
Foods that prevent cancer are your fresh fruits and vegetables with some exceptions such as grapefruit which has been implicated in causing cancer if eaten in abundance by post menopausal women.
To read about all this and how the standard American protein-based diet causes cancer and heart disease and other diseases and how eating a plant-based low calorie nutrient-dense diet can prevent or even reverse cancer and heart disease read any or all of the following books:
EAT TO LIVE
EAT FOR HEALTH
THE FOOD REVOLUTION
THE CHINA STUDY
THE RAVE DIET AND LIFESTYLE
there are 200 kinds of cancer. Cancer can be caused by different things such as cigarette smoking or diet or exposure to chemicals and poisons and other factors. The symptoms and treatment would be no different regardless of the cause. However, diet is the best defense and way of preventing cancer which is emphasized in the above books.
Also, highly recommended is CANCER: STEP OUTSIDE THE BOX by Ty Bollinger
http://search.yahoo.com/search?p=ty+bollinger&fr=ush-shopping&ygmasrchbtn=Web+Search