Strategies for Prevention

  
 
EVIDENCE
 
Question: What strategies can be adopted for  preventing cancers in populations?
How can these strategies be operationlaised? 
Absence of evidence is not evidence of absence  [?]
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There are some mainstream recommendations about diet, nutrition, and cancer adopted by the National Academy of Sciences, National Research Council, The American Cancer Society, and The National Cancer Institute.
 
 
Some guidelines from the National Cancer Institute:
 
 
1. Reduce fat to 30% of total daily calories or less. When you eat away from home, choose food low in fat, calories, and sugar and avoid large portions.Eat smaller portions of high-calorie foods. Be aware that “low fat” or “fat free” does not mean “low calorie” and that low-fat cakes, cookies, and similar foods are often high in calories.Substitute vegetables, fruits, and other low-calorie foods for calorie-dense foods such as French fries, cheeseburgers, pizza, ice cream, doughnuts, and other sweets.
Limit consumption of red meats, especially those high in fat and processed.
·        Choose fish, poultry, or beans as an alternative to beef, pork, and lamb.
·        When you eat meat, select lean cuts and smaller portions.
Prepare meat by baking, broiling, or poaching, rather than by frying or charbroiling.
 
2. Increase fiber intake to 20 to 30 gm/day, with an upper limit of 35 gm/day. Choose whole grains in preference to processed (refined) grains and sugars.
·        Choose whole grain rice, bread, pasta, and cereals.
·        Limit consumption of refined carbohydrates, including pastries, sweetened cereals, soft drinks, and sugars.
 
 
3. Include a variety of vegetables and fruits in the daily diet. Eat five or more servings of a variety of vegetables and fruits each day.
·        Include vegetables and fruits at every meal and for snacks.
·        Eat a variety of vegetables and fruits.
·        Limit French fries, snack chips, and other fried vegetable products.
Choose 100% juice if you drink fruit or vegetable juices.
5. Consume alcoholic beverages in moderation, if at all.   Alcohol is an established cause of cancers of the:
·        Mouth
·        Pharynx (throat)
·        Larynx (voice box)
·        Esophagus
·        Liver
·        Breast
Alcohol may also increase the risk of colon cancer.
 
 
6. Minimize consumption of salt-cured, salt-pickled, and smoked foods.
 
 
4. Avoid obesity. Being overweight or obese is associated with an increased risk of developing several types of cancer:
·        Breast (among postmenopausal women)
·        Colon
·        Endometrium
·        Esophagus
·        Gallbladder
·        Pancreas
·        Kidney
 
Adopt a physically active lifestyle.
Adults: Engage in at least moderate activity for 30 minutes or more on 5 or more days of the week; 45 minutes or more of moderate to vigorous activity on 5 or more days per week may further reduce the risk of breast and colon cancer.Children and adolescents: Engage in at least 60 minutes per day of moderate-to-vigorous physical activity for at least 5 days per week.
Cancer Prevention
 
One out of five male deaths in the U.S. is due to cancer. But many cancers are preventable, and early screening makes them treatable. Learn the facts about cancer. Then take action to protect yourself.
 
Common Cancers In Men
 
The deadliest cancer in men is also the easiest to prevent: lung cancer. It is estimated to kill nearly 94,400 American men in 1996. Colorectal (colon and rectum) cancer and prostate cancer are also common but, when caught early, are highly treatable.
 
Colorectal Cancer Prevention
 
Prevent colorectal cancer by eating a high fiber, low fat diet. Increase fiber by eating whole grains, fresh fruit, and vegetables. Drink low fat or nonfat milk for calcium. Eliminate saturated fats, using olive or safflower oil instead.
 
Colorectal cancer is easily diagnosed and treatable.
All men over 40 should get an annual colorectal cancer screening, a simple, painless procedure that checks for early signs of this type of cancer.
 
 
Lung Cancer Prevention - Stop Smoking
 
Smokers are as much as 25 times more likely than nonsmokers to get lung cancer. But 15 years after they stop, their odds are the same as nonsmokers'.
Dramatically reduce your risks of getting lung cancer: quit smoking. Wear the right protective equipment at work, and eat foods high in Vitamin C (fresh fruit and vegetables).
Those exposed to asbestos or radon also have higher risks if they do not wear protective equipment.
 
Prostate Cancer Prevention
 
Prevent prostate cancer: lower the fat in your diet by eating broiled or baked (not fried) fish and chicken, less meat, and salads with less dressing.
Most important is an annual rectal exam after age 50, when prostate cancer is most common.
A high fat diet, and regular exposure to cadmium in jobs like welding, electroplating, and alkaline-battery making, may increase your risk.
 
 
LlEUKEMIA
At present, there is no way to prevent their leukemias from developing.
People with a known inherited tendency to develop leukemia should receive thorough, periodic medical checkups. The risk of leukemia in these syndromes, (because of Li-Fraumeni syndrome or Down's syndrome, for example) although higher than that in the general population, is still extremely rare. [check out what these are?]
An estimated 20% of adult acute leukemia cases are related to smoking tobacco. Smoking, which doubles the risk of acute myeloid leukemia in people over 60 , is by far the most significant controllable risk factor.
Treatment of other cancers with chemotherapy and radiation may cause secondary (post-treatment) leukemias.
Avoiding known cancer-causing industrial chemicals, such as benzene, can lower the risk of developing acute leukemia. But most experts agree that occupational and environmental chemicals are responsible for only a small number of leukemia cases.
Esophagus Cancer
Risk factors such as age, sex, and race cannot be changed.
The most important risk factors for cancer of the esophagus are tobacco and alcohol abuse.
The risk of esophageal cancer increases by 18 times in people who drink more than 80 grams (about 13 ounces) of alcohol a day for years.
If this same person smokes at least 1 to 2 packs of cigarettes a day, the risk of esophageal cancer increases 44 times.
Avoiding these two factors is the best way to reduce the risk of esophageal cancer.
Also, since obesity has also been associated with esophageal cancer, physical activity and maintaining a healthy weight can reduce the risk of this disease.
Some studies have found that the risk of cancer of the esophagus is reduced in people who take aspirin or other nonsteroidal anti-inflammatory drugs such as ibuprofen.
 
Hodgkin's Disease
What little we know about the risk factors has not yet been translated into practical ways to prevent Hodgkin's disease.
Non-Hodgkin's Lymphoma
For now, the only opportunity for trying to prevent non-Hodgkin's lymphoma is by preventing known risk factors such as acquired immune system deficiencies (AIDS). Recent discovery of the connection between Helicobacter pylori infection and primary gastric lymphomas offers a potential opportunity for prevention. The benefit of this strategy has not been proven yet.
(Teaching Aid 1)
Early detection of cancer

early diagnosis in symptomatic populations
screening in asymptomatic, but at risk, populations
Increasing awareness of the signs and symptoms of cancer
 
Early detection is only successful when linked to effective treatment particularly for cancers of the
§         breast
§         cervix
§         mouth, larynx
§         colon and rectum
§         skin
 
Managing national cancer control programmes
 
prevention, early detection, treatment and palliation,
 
PREVENTION
Of 10 million new cases of cancer each year are preventable by such means
 as controlling tobacco and alcohol use,
 healthy diet,
 immunizing against viral hepatitis B.
 
Early Detection
cancers of the breast, cervix, mouth, larynx
 
Involves
Education of
      Health Professionals
            Populations – General
                                - High Risk
 
(Teaching Aid 2)