Health Issues Cancer

I just read about a new study that suggests that the risk of developing cancer is not just down to "bad luck", but overwhelmingly due to external factors. Only 10-30% of cancers were down to the way the body naturally functions.

Cancer is not just 'bad luck' but down to environment, study suggests - BBC News

I also read a few articles about the environmental factors that contribute to certain factors. Pollution, junk food, smoking and alcohol also contribute to many cancers.
 
Does Vitamin D Really Protect Against Colorectal Cancer? -- NPR Choice page
Now a large international study provides the strongest evidence yet that vitamin D may indeed be protective against colorectal cancer and that a deficiency may increase the risk of this cancer. The findings appear Thursday in the Journal of the National Cancer Institute.