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How Cancers Start




Excerpted from
Live Now, Age Later: Proven Ways to Slow Down the Clock
By Isadore Rosenfeld, M.D.

When a body organ or tissue needs to replace cells that are worn out or have died, its healthy cells divide and increase in number. They do so in an orderly way, and produce no more cells than are necessary. The cells of cancerous tissue, on the other hand, multiply for no reason, and they do so like crazy, without rhyme or reason. Their lack of restraint is probably triggered by some damage to their DNA, which results in a change (mutation) of one or more critical genes. For example, uncontrolled cell division occurs when P53, a tumor suppressor gene whose job is to regulate cell division, is inactivated or mutated. So cancer is a disease of the genes, a malfunction of the proteins (DNA) in our chromosomes.

This exuberant cellular multiplication results in a "growth" or tumor that is either benign or malignant. When a tumor is benign, it stays in one place; its cells do not spread to other parts of the body , it rarely threatens life; and it almost never recurs after it's removed. Cancers, by contrast, invade and press on adjacent organs and tissues; their cells later break away from the parent growth (the primary), enter the bloodstream or the lymphatic system, and travel throughout the body, settling all over the place. This spread is called metastasis.

Cancer and Aging

Although cancer strikes both young and old, it is primarily a disease of aging. In the United States, 50 percent of all malignancies and 67 percent of cancer deaths occur in persons over the age of sixty-five. (That's currently one American in eight; by the year 2030, it's expected to be one in five.) Yet, even though they are ten times more likely than younger persons to develop cancer, the elderly are not screened as often; they're referred less frequently to major cancer centers where they have a better chance of being cured; and they're usually treated less aggressively for their disease.

Older people are more vulnerable to cancer because of their longer exposure to carcinogens: pollution, radiation, tobacco, sun, alcohol, the wrong diet, chemical or physical irritation, hormonal imbalance, and possibly even stress. Random genetic mutations that lead to cancer also occur more frequently. The body's DNA repair system, which is constantly on the lookout for dangerous changes that may cause a cell to become cancerous-and aborts the cell when such mutations are detected-is less effective as we grow older.

The outcome of cancer in many older persons is adversely affected by a combination of social, psychological, educational, financial, cultural, and economic factors. The elderly are not always aware of all the hows, whys, and wheres of cancer diagnosis and therapy because much of the pertinent educational material is not geared toward them. As a result, they may assume that all cancers are uniformly fatal, and that there's nothing to be done about them. They may attribute their symptoms to some other cause, or to "old age" and they put off seeing a doctor until it's too late. They may have legitimate concerns about their ability to pay for the care they need, especially since many services, such as outpatient drugs, transportation, home care, and medical supplies, are not covered by Medicare. Some of my elderly patients have refused expensive procedures and not filled their prescriptions because they couldn't afford them. If they live in social isolation, without a strong support network of family, friends, and neighbors, they may not be able to get to the clinic or the doctor's office because they don't have a car or can't drive, or they have physical limitations. Finally, the chances of curing their cancer may be affected by a coexisting chronic illness, such as a respiratory problem, arthritis, diabetes, or heart trouble. Some or all of these factors are not always taken into account, given the medical establishment's preoccupation with profit, statistics, efficiency, and technology.

Preventing Cancer

A complex mix of factors related to environment, lifestyle, and heredity plays a role in the causation of cancer. For example, 80 percent of all cancers are related to the use of tobacco products, to what we eat and drink, and to our exposure to radiation, asbestos, and some of the other cancer-causing agents. There's not much you can do about your genes (at the moment), but several other key risk factors are under your control. If you identify them and make the necessary changes in your lifestyle early enough, you can substantially decrease your chances of developing a malignancy. Here are some of the risk factors you can do something about:

Tobacco is the most preventable cause of mortality in this country. Regardless of whether you chew it, snuff it, smoke it, or inhale someone else's "exhaust" (passive smoking causes about 3,000 lung-cancer deaths every year), tobacco is a killer. In the United States, it is responsible for 85 to 90 percent of all lung cancers, and for one-third of all deaths related to other cancers (mouth, larynx, esophagus, stomach, pancreas, bladder, kidney, cervix, leukemia, and possibly colon). The magnitude of the risk depends on the number and kind of cigarettes you've smoked and for how long. A pack-a-day smoker is ten times more vulnerable than a nonsmoker. It's never too late to quit. After you do, your cancer risk declines gradually each year.

Chronic alcohol abuse can cause cancer of the liver, as well as of the mouth, throat, esophagus, and larynx, especially in combination with tobacco. It may also raise the risk of breast cancer. If you're going to imbibe, limit yourself to the equivalent of two drinks a day-and stop smoking.

Diet: People who shun fruits and vegetables have roughly twice the incidence of most types of cancer-lung, larynx, oral cavity, esophagus, stomach, colon and rectum, bladder, pancreas, cervix, and ovary-than those with the highest intake. Yet only 9 percent of Americans heed the recommendations of the National Cancer Institute and the National Research Council to eat two servings of fruit and three portions of vegetables a day. Seventh-Day Adventists, who don't drink or cat much meat but do consume a diet rich in fruits and vegetables, have the lowest incidence of cancer in the U.S. population. This protective effect is probably due to the antioxidants and folic acid present in fruits and vegetables, which neutralize damage to chromosomal DNA caused by oxygen-free radicals.



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