In the U.S. cancer will claim the lives of half a million people annually, and 1.5 million new cases of cancer will be diagnosed each year. The three most common cancers among men are prostate cancer, lung cancer and colorectal cancer, in that order of frequency. The three most common cancers among women are breast, lung, and colorectal cancers. Not as commonly known is that lung cancer is the cancer that kills most women, even more than breast cancer.
The genetics we are born with certainly play a big role in determining our susceptibility to cancer. While we can't change our genetics, there is a great deal of information available, which teaches us the things we can do (and not do) to increase our chances of not developing cancer or to survive cancer.
It has been estimated by the American Cancer Society that being overweight or obese contributes to 14% of all cancer-related mortality. With two-thirds of Americans being overweight and half of those being obese, this becomes a very important statistic. At lease 20 cancers are associated with being overweight. And cancer death rates are 50-60% higher in obese men and women.
Physical inactivity is also directly associated with risk of contracting various cancers. A person's degree of physical activity is also likely predictive of their chances of surviving cancer.
A high Vitamin D level is likely protective against both breast and prostate cancer (though there is some conflicting data). The high incidence of prostate cancer among African American men may well be due to the high rate of Vitamin D deficiency in people with darker skin (which prevents the sun from creating Vitamin D).
Alcohol and tobacco use are clearly associated with increased risks of certain cancers. But other dietary influences such as saturated and trans fats and other environmental exposures can cause cancer.
A book that addresses the role of diet in cancer is “The China Study” by T. Colin Campbell, which is the most comprehensive study of the role of nutrition in causing disease ever conducted. He makes a strong case for the role of dairy and animal meats and fats in causing an increased incidence of cancer and for vegetables and fruits being protective.
Eat lots of vegetables and fruits (of different colors), limit meat and dairy, exercise regularly. Don't smoke (or quit if you do) and limit your alcohol intake. And regular skin exams, breast exams and imaging, and colonoscopies can help reduce the incidence of three of the most common cancers.