Another reason among many to do all you can to avoid cancer: The damage chemotherapy can do on your body -- especially to your brain -- can last a decade, if not longer, after treatment.

Using positron emission tomography (PET), UCLA researchers compared the brain scans of 21 female patients who had undergone surgery within the previous decade to remove breast tumors against those of 13 healthy patients while performing short-term memory exercises and afterward. Of that group of breast cancer patients, 16 had been treated prior to their surgeries with chemotherapy.

The PET scans among breast cancer patients who had chemotherapy showed a lower metabolism in a key region of the brain's frontal cortex. The lower rate of a patient's resting metabolism was, scientists said, the more difficulty she would have performing memory tests. Scientists also noticed jumps in blood flow to the cerebellum and frontal cortex, a sign the brains of women who had chemo worked harder to perform normally than did healthy patients.

What's more, chemotherapy patients who also underwent hormonal therapy also experienced an 8 percent drop in the resting metabolism in another area of their brain (the basal ganglia).

The best thing you can do to avoid cancer, now the leading killer of Americans, and obscenely expensive drugs that will likely do you more harm than good: Follow my major recommendations that are far more comprehensive than those suggested by the American Cancer Society.

Breast Cancer Research and Treatment September 29, 2006

Science Blog October 5, 2006

Yahoo News October 5, 2006

USA Today October 5, 2006