Cancer: More Environmental than Genetic

More than 85 percent of the known causes of cancers are environmental, not genetic. Normal cells undergo apoptosis, a process in which each cell lives only so long and then dies. Cancer means that the DNA in cells cannot do its usual job of telling a cell when to die, so the cells grow forever and can spread to other parts of the body to kill you. Scientists have developed drugs and other treatments to destroy the process that makes cancer cells immortal. However, each cancer cell has hundreds, and even thousands, of different pathways that they can use to make them live forever. Pancreatic cancer cells have an average of 63 mutations (Science, September 4, 2008), and a brain tumor called glioblastoma has at least 47.

So when scientists develop a drug to kill a cancer, the drug acts on one or more pathways and may temporarily inhibit the cancer, but drugs never block all the pathways that can go wrong. Therefore cancer can always come back. That is why doctors often use as many as five different drugs to treat some cancers because they want to block as many of the different pathways as possible.

At this time, I believe that the best approach is to avoid or limit your exposure to known or suspected environmental triggers for cancers, which include:

- meat, particularly beef (eating red meat is associated with increased risk for 17 different cancers)
- barbecued, grilled or deep-fried foods (browning or burning foods, particularly fats or starches, forms carcinogens)
- BPA (Bisphenol A) in some plastics
- PCB's
- lead in any form
- molds such as aflatoxin from rotten peanuts or grains
- arsenic in well water
- asbestos in old buildings
- sexually transmitted diseases such as hepatis C that causes liver cancer or HPV, the human wart virus that causes cervical cancer
- formaldehyde or carbon tetrachloride
- Helicobacter pylori (bacteria that cause stomach burning and ulcers) which can cause stomach cancer
- unnecessary X rays, particularly CAT scans
- heavy exposure to pesticides
- radon from the ground leaking into your house
- tobacco in any form
- second-hand smoke
- alcohol (more than three drinks a day increases cancer risk)
- exposure to uranium
- excessive UV radiation (too much sunlight)
- not enough sunlight (lack of vitamin D)
- night shift work (depresses melatonin, a cancer-preventing hormone)

Other cancer risk factors include lack of exercise, excess weight, lack of fiber in the diet, a diet that is low in vegetables, early puberty in women (before age 12), late menopause (after age 55) or taking estrogen after menopause. In 2008, cancer will take the lives of about 230,000 more Americans than it did in 1971. Try not to be one of them.