LAKEWOOD, Ohio, June 6 (UPI) -- After more than three decades, the U.S. government's "War on Cancer" has produced numerous breakthrough chemotherapy treatments that have turned some cancers from killers into chronic diseases. But the war will not be won until cancer can be prevented, and prevention remains mired in myriad -- and often conflicting -- reports about the risks associated with diet, lifestyle and even work.
Over the past five years, well-respected medical and scientific journals have published reports suggesting tomatoes, black raspberries, green tea, black tea, grape skins -— the list is endless -- can reduce the risk for certain cancers. Meanwhile, hair dye, beer, milk —- another lengthy list -- are reported to increase the risk.
Twenty year-olds who have babies and nurse them might reduce their risk for breast cancer, while simultaneously lowering their incomes by restricting their job opportunities.
This week researchers at Harvard Medical School reported women who worked at least three night shifts a month for 15 years or longer face a 35 percent increased risk for intestinal cancers and a 41 percent increased risk for colon cancer. The same Harvard group reported previously that nightshift work increases the risk of breast cancer.
There is little doubt if cancer could be prevented, millions of lives and billions of dollars could be saved. This was the original goal when the National Cancer Act was signed into law by President Richard M. Nixon in 1971.
Consider these numbers: More than 1.2 million Americans develop cancer each year. A new cancer is diagnosed every 30 seconds in the United States. Since 1990, nearly 15 million new cancer cases have been diagnosed.
The data do not include non-invasive skin cancers, or most of the pre-cancerous tumors called carcinoma in situ, which are found in virtually every organ in the body, and which usually require surgery to remove. Nor do they include basal- and squamous-cell skin cancers.
The National Institutes of Health puts the annual bill for cancer at more than $180 billion, which includes, among other costs, $15 billion for cancers that are successfully treated and more than $105 billion for lost productivity due to premature death.
That is what makes cancer prevention such a sought-after goal, said Dr. Judy E. Garber, director of cancer risk and prevention at the Dana-Farber Cancer Institute in Boston. Garber takes a cautious approach to prevention and warns many studies must be conducted to identify either a risk factor or a risk reducer with precision.
The nightshift study illustrates the point. The findings are culled from the Nurses' Health Study, an ongoing examination of about 80,000 nurses. Data from this same study suggested hormone replacement therapy could reduce the risk of heart disease, a finding that was contradicted spectacularly when the treatment was tested in a randomized, placebo controlled study and found hormone therapy actually increased the risk.
This reinforces the need for a steady, proven approach to prevention, concludes the American Society of Clinical Oncology and the Cancer Research and Prevention Foundation. The two groups jointly funded a telephone survey asking Americans what they know about cancer prevention. The first answer is: not much. The second: often, what the public does claim to know is wrong.
The survey sampled 1,000 adults. Although 88 percent of those contacted said they thought they could do certain things to reduce cancer risks, most often they did not know what those "things" were. Or, they said they routinely ignored known risks.
For example, about half of the respondents said they did not think regular exercise could reduce cancer risk, even though several studies have found exercise can curb both breast and colon cancer and the current recommendation is to perform at least 30 minutes of exercise, five days a week -- a recommendation echoed by the American Heart Association to reduce the risk of heart attack.
Worse, only about one-third of those surveyed correctly connected being overweight to increased cancer risk, despite much publicized studies linking about one-third of new cancers of the breast, colon, and pancreas to obesity.
About three in every 10 Americans said taking vitamins or herbal supplements can reduce cancer risk. This is not only wrong, according to cancer experts, but it also can be dangerous. A 1996 study showed people who smoked and took beta-carotene supplements actually increased their risk of dying from lung cancer.
Diet is an important factor in prevention, said Garber. A cancer-prevention diet is rich in fruits and vegetables and low in fat, she said, noting, "the nutrients should come from foods, not from supplements."
The public, however, seems eager to accept a cure-in-a-bottle approach to cancer. Hence, the widespread interest in vitamins or supplements to reduce the risk. In response to that perception, researchers have conducted exhaustive studies looking for a magic bullet.
In some cases, this approach has paid off. Taking non-steroidal anti-inflammatory drugs has reduced colon cancer risk, according to several studies. Vioxx and Celebrex, two anti-arthritis drugs, currently are being tested in people genetically predisposed to colon cancer.
Studies of anti-high-blood-pressure drugs called ACE inhibitors suggest taking these medications daily results in a lower cancer risk compared with other high blood pressure drugs. A team of Dutch researchers reported last Sunday people who take cholesterol-lowering drugs called statins for four years reduce their risk of kidney or prostate cancer by 36 percent.
Dr. Michael Friedman, president and chief executive officer of the City of Hope cancer research center in Duarte, Calif., and deputy commissioner of the Food and Drug Administration during the Clinton administration, argues a "prevention pill" is a wrong-headed approach to cancer.
Unlike daily aspirin to prevent heart attack, which costs less than $5 a month, a month's supply of statins costs $100 to $200, so statins simply are too expensive to be used for primary cancer prevention, he said. Moreover, Friedman finds it unlikely people will take a pill to prevent cancer.
"It is difficult enough to get people to take the drug for high cholesterol when they can see the results of their cholesterol tests," he said. "Why would they take a pill to reduce a theoretical risk of cancer?"
Given this background, what practical —- and economically feasible -— prevention strategies should people pursue?
By wide consensus, here are the basics:
--Eliminate tobacco,
--Maintain normal weight,
--Exercise regularly,
--Put sunscreen on at home, not when outside exposed to damaging rays, and
--Eat a diet rich in fruits and vegetables.
Boring? Yes. Doable? Lives and livelihood might depend on it.
