Philip J. Goscienski, M.D.
Overweight Americans outnumber their normal-weight neighbors by a whopping three to one. In some cities of our Southeast it's even more lopsided than that and there's no indication that things are going to change in the next generation or two. That is going to make cancer a more serious threat than it is now for reasons that most people don't think about.
By the end of this decade overweight will overtake smoking as the primary preventable cause of cancer. Having more fat cells on board is a major factor in developing several types of cancer. The risk of dying from breast cancer is 50 percent greater for obese women. From one-quarter to one-half of cancers of the colon, esophagus, kidney, pancreas and uterus are associated with obesity.
Estrogen, the female hormone, is just one of many chemicals churned out by fat cells. Higher estrogen levels are linked to cancer of the breast and uterus. Obese women are more likely than slender ones to become victims. In fact there is an almost linear relationship between the amount of fat a women has and the risk of these cancers.
Insulin is another factor in the fat-cancer relationship. It isn't produced by fat cells but this hormone reaches higher levels in overweight persons who tend to get that way because of a diet that is high in refined carbohydrates. It acts as a growth stimulant and it may prod cancer cells to grow and to spread.
There are other reasons why maintaining a healthy weight is an advantage in controlling cancer.
It wasn't long ago that diagnostic techniques such as the CAT scan (computerized axial tomography) and the MRI (magnetic resonance imaging) emerged that were able to reveal cancerous growths when they were in the earliest, most treatable stage. As anyone who has endured several minutes of claustrophobic nervousness in one of those chambers is aware, they are not designed for massive bodies, sometimes weighing more than 500 pounds, that doctors now deal with regularly. Although the industry is developing oversized units to accommodate the morbidly obese, not all hospitals are so equipped.
Radiologists complain that they are simply unable to decipher the results of scans of bodies whose internal organs are shielded by several inches of fat. This is hardly a rare situation. One radiologist estimates that 10 to 15 percent of images in obese persons are limited by the size of the patient. Delayed diagnosis is inevitable when physicians cannot use all the tools that are available.
How about treatment with radiation? Excess body fat plays a role here as well. There is a very high failure rate of radiation therapy in obese patients with prostate cancer. As the obese population increases in number it will be necessary to explore whether those with other types of cancer face similar high rates of treatment failure.
Designers of chemotherapy programs have only recently been faced with large numbers of obese cancer patients but it's already evident that some are not receiving the correct dose of drugs because precise calculations are difficult.
There are many reasons for maintaining normal weight. Add cancer to the list.
Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at firstname.lastname@example.org.