When the National Cancer Institute and Harvard researchers published reports in May linking alcohol consumption to breast cancer, some women were so alarmed they promptly stopped drinking anything alcoholic.
That`s not a bad idea, especially if a woman has a family history of breast cancer. But doctors familiar with the disease say that abstinence from alcohol is worthless if a woman continues to eat more than a minimal amount of fat. The link between a high-fat diet and breast cancer is stronger, they say, than the new evidence indicting alcohol.
Also, for some people, a little alcohol may be a good thing because it could protect them from America`s No. 1 killer, heart disease.
Even Dr. Arthur Schatzkin, the lead researcher in the National Cancer Institute study, has said, ”The available evidence does not prove that alcohol consumption causes breast cancer, and it is not strong enough to support a public health recommendation.” His comment has become the official position of the cancer institute.
Nevertheless, Dr. Marc Wallack, chief of surgery at Mt. Sinai Medical Center in Miami Beach who has operated on many women with breast cancer, is reluctant to dismiss the report.
”The amount (of alcohol) is not relevant,” he said. ”The thing that`s relevant is there could be a link, and we have to take that seriously.
”Women who are at risk, women who have (lumpy) breasts and a family history and are drinking three drinks a week, should try to eliminate alcohol from their diet.
”Would I recommend for all women to stop drinking alcohol? I am not sure I can do that on the basis of the article.”
The American Cancer Society advises women with known breast-cancer risks to weigh drinking as a possible increased hazard. But the society, which anticipates 130,000 new cases of breast cancer this year, is not recommending that all women cease drinking.
”More research has to continue in this area,” said Joann Schellenbach, spokeswoman for the American Cancer Society. ”Even though there are now 14 studies showing some kind of correlation, it`s not what you would call a large body of work.”
Schellenbach and other critics note that all the evidence so far is based on epidemiology, the study of disease as it occurs in groups of people. More study is necessary to show how and why cancer is occurring, Schellenbach said. Therein lies the problem for a woman trying to decide what to do. While several groups of scientists have suggested that there may be a link, other scientists are saying, ”Fine. Now tell us why.”
Once, such a dialogue would have been restricted to the scientists. Now, the New England Journal of Medicine`s weekly scientific reports are relayed frequently to the public, which often is confused because science seldom deals in absolutes.
For example, if you drive a car into a wall at 60 miles an hour, you are quite likely to die. That is an obvious conclusion.
But deciding what causes disease is rarely that clear.
The recently published reports suggest-and ”suggest” is the operative word in both studies-that a young woman who drinks an alcoholic beverage three times a week might increase her risk of breast cancer by 50 percent.
Because women overall have a 10 percent chance of developing breast cancer, the studies` findings appear to increase the risk to 15 percent for the moderate drinker.
The kind of drink might make a difference, though, according to one group of researchers.
”The risk of breast cancer associated with alcohol intake from beer and liquor remained significantly elevated, but the association with wine was reduced and not significantly different from that in nondrinkers.”
Dr. Edward Trapido, chief cancer epidemiologist at the Papanicolaou Comprehensive Cancer Center in Miami, knows most of the scientists from the National Cancer Institute and from Harvard, whose reports linking alcohol and breast cancer were published in the New England Journal of Medicine on May 7. ”The actual studies are excellent,” Trapido said. ”I have worked with both groups of people, and they are extraordinarily well qualified.”
Nevertheless, he has doubts because the studies increase the normal risk of breast cancer by only .5 if the woman drinks. Possible errors on the part of the women reporting their habits could reduce that risk even more, he said. ”Let`s say, in smoking and lung cancer we found a relative risk of 20 times normal,” Trapido said. ”Then, if there were biases, the difference between 18 or 17 times and normal risk would still be very large. But in 1.5, you can`t be all that sure. Let`s say it`s really 1.3 or 1.2. It`s such a minimal increase, it`s hard to know what real meaning it has.
”Many epidemiologists would say 1.5 is the elevation of 50 percent of risk. That`s the smallest thing you take seriously. It`s really only a relative risk of 2 (a doubling of normal risk) that we take into account.”
This doesn`t mean Trapido dismisses the new evidence.
”Maybe people should look at it,” he said. ”Breast cancer is so common that even with a minimal risk, that might mean 15,000 to 30,000 more cases nationally.”
There is, however, something else to consider:
Moderate alcohol use has been shown to elevate HDL cholesterol, the
”good cholesterol” that carries away LDL cholesterol, which is the one most likely to cause the buildup of fats and hard plaque (a kind of scar) on the lining of arteries. That buildup can block circulation or trap clots, leading to heart attacks and strokes. So, it seems, a small amount of alcohol may be good for some people, especially if there is a family history of heart attack.
Although women generally are considered at much less risk than men of dying from heart disease, they rapidly catch up with men in terms of risk after menopause. The reason is that older women lose the protective effect of the hormone estrogen.
Adding to the uncertainty about the alcohol-cancer link are what doctors call ”multifactorial” influences on the development of disease. No one knows exactly how, when, why or which foods, drinks, genetic influences, shocks, stresses or other factors cause the body`s cells to go wild and produce a cancer. Thus, while no medical professionals are dismissing the new evidence regarding alcohol, some wonder whether a woman trying to save herself from breast cancer might put herself at greater risk of heart disease.
”I would actually advise people to take two shots (of alcohol) a night,” said Dr. David Schapira, chief of the cancer prevention section at the H. Lee Moffitt Cancer Center, in Tampa.
”Despite breast cancer being common, the commonest killer in men and women is atherosclerosis (hardening of the arteries) and cardiac disease. With a very slight possibility that alcohol might be linked to cancer, it`s going to be a distracting factor from fat.”
Schapira ranks the alcohol risk, along with food additives, as possibly
”playing a minor role” in cancer development.
”There`s definitely not enough evidence to say it`s a strong factor in breast cancer,” Schapira said, ”and it`s protective in cardiovascular disease. I think a lot more evidence needs to come out, both in other human studies and in animal data, to see if there is any tie-in.
”You put animals on a high-fat diet and they get many more cancers. You cut it down and the cancer development decreases. I don`t think anyone has shown that kind of relationship with alcohol in animals.”
Established breast cancer risks include:
– Strong family history of breast cancer, especially if a mother, sister or aunt has had the disease. (However, a woman with no family history cannot relax: Breast cancer frequently occurs in those without obvious risk.)
– No children, or first child born after age 30.
– Obesity.
– Early menarche (start of menstrual periods) and late menopause.
Risk increases with age; the American Cancer Society considers being over 50 a risk factor. But the newly described alcohol-cancer link was found more often among slim young women.
”I just had a 39-year-old patient ask me about alcohol,” said Dr. Nilza Kallos, radiologist-director of the Diagnostic Breast Center in South Miami.
”Her sister, mother and grandmother had breast cancer. I told her that, in her case, she already has such a high risk she should stay with less than one drink a week.”
Kallos considers it ”a little idealistic” to expect women to quit drinking altogether in light of the evidence.
”Alcohol is so prevalent in our society that I think people are going to continue drinking,” Kallos said.
”We know fatty food consumption increases breast cancer, and people don`t become vegetarian (because of that). I recommend for people who have a strong family history that they should make fat less than 20 percent of their caloric intake, and not to have more than one drink a week.”
Further information and booklets describing cancer risks, prevention, symptoms and treatment are obtainable from the Cancer Information Service. Call 800-4CANCER.
