Jewish World Review August 2, 2002 / 24 Menachem-Av, 5762




Mammography Saves Lives!

By Robert A. Wascher, M.D., F.A.C.S.

http://www.NewsAndOpinion.com | The controversy surrounding a mammography study, published in Lancet last year by Danish researchers, would appear to be quashed by a new study published in the current issue of the journal Cancer. In the Lancet study, a statistical review of previous Swedish studies showing a reduction in death rates with routine screening mammography concluded that these prior studies were flawed, and that there was no evidence that mammography saved lives.

Subsequent critiques of the Lancet paper have largely eviscerated that conclusion, but patients and doctors around the world were left stunned and uncertain about the implications of this controversy. The current study in Cancer looked at breast cancer-related death rates in women aged 40 to 69 years, comparing women who received routine screening mammograms with women who did not. The study evaluated nearly one-third of all Swedish women, and detected the occurrence of 14,092 cases of breast cancer, and 2,044 deaths due to breast cancer, among the women studied. After more than 10 years of follow-up, the researchers found that routine screening mammography reduced the risk of dying from breast cancer by about 44%.

This finding is consistent with the observations of cancer physicians over the past 20 years, as routine screening mammography has become been widely implemented throughout most developed nations, including the United States. It has long been known that breast cancer survival rates correspond to the extent of disease, or stage, with an excellent survival rate present for women with small primary tumors and no evidence of cancer spread outside of the breast. Most of the previous studies that have failed to find a survival benefit associated with mammography followed study volunteers for only 5-10 years.

Compared to many other cancers, breast cancer is often a relatively slow-growing cancer, and the relatively long natural course of the disease requires at least 10 years of study prior to drawing any firm conclusions. This new study in Cancer highlights this fact by showing progressively increasing survival benefits from screening mammography beyond 10 years of observation. This study, as well as other studies published this spring, convincingly show that mammography saves lives, and probably by diagnosing breast cancers when they are still very small and confined to the breast. While 10-15% of breast cancers do not show up on mammograms, mammography is still the single most sensitive and accurate screening tool available for the early detection of breast cancer. All women should generally begin screening mammography at 40 years of age.

OBESITY & THE RISK OF HEART FAILURE

Approximately 8% of Americans are thought to be morbidly obese (weight 100 lbs greater than ideal body weight), while about 55% of the population is overweight (Body Mass Index, or BMI, 25.0-29.9) or obese (BMI >30). Morbid obesity is associated with a greatly elevated risk of heart failure, high blood pressure, diabetes, blood clots, lung disease and other life-threatening maladies. Heart failure occurs when the heart's pumping chambers can no longer pump enough blood to meet the body's needs. According to the National Heart, Lung, and Blood Institute, 5 million Americans have chronic heart failure, and half of these people will succumb to their disease within 5 years. The incidence and death rate due to heart failure is increasing. Each year, 400,000 new cases are diagnosed, and the number of annual deaths due to this condition have more than quadrupled over the past 30 years.

A new study, appearing in this week's New England Journal of Medicine, looks at the effects of excess weight and obesity on the incidence of congestive heart failure. Specifically, the study looked at rather moderate degrees of obesity among nearly 6,000 participants in the ongoing Framingham Heart Study. The BMI of study volunteers was calculated (BMI = weight in kilograms divided by the square of the height in meters), and the incidence of heart failure was noted during the average 14 years of study follow-up. Causes of heart failure unrelated to obesity were considered and corrected for in reaching the study's conclusions. For every BMI incremental increase of 1 unit, there was a 5% increase in the risk of heart failure among men, and a 7% increase among women. When compared with people who had a normal BMI (<25), obese volunteers had a doubling of the risk of heart failure.

This study is yet another warning sign that the epidemic of excessive weight and obesity in our country is a dangerous development in terms of individual and public health. Moreover, this is the first study to conclusively demonstrate that even relatively modest levels of excessive weight are associated with significant increases in the risk of potentially life-threatening heart disease. Rather than suing McDonalds or Burger King for the unhealthy nutritional content of some of their menu items, maintaining a healthy low fat diet and a regular exercise schedule would appear to be a more effective strategy to maintain good health.

HIGH SUGAR DIETS & THE RISK OF COLON CANCER

In the current issue of Cancer Research is a study that looks at the effects of high sugar diets and the risk of colon cancer. There have been previous research studies that have linked high concentrations of dietary sugar with precancerous changes in the lining of the colon and in the liver, although such findings have been rather inconclusive to date. In this study, laboratory rats were fed diets containing various levels of sugar. The study identified an increasing incidence of a mutation associated with colon cancer in the lining of the rats' colon with increasing levels of dietary sugar. No cancer-associated changes in the liver were identified with respect to dietary sugar levels, however. The study appears to show that, at least in rats, table sugar (sucrose) can directly or indirectly cause DNA mutations that have previously been associated with the development of colon cancer.

So, in addition to staying on a low fat diet to protect your heart and other vital organs, you might also want to watch the amount of sugar in your diet. In addition to possible adverse effects on the colon, high levels of sugar in the diet are associated with an increased risk of diabetes, obesity and reduced lifespan.

ABUSE DURING CHILDHOOD & POSSIBLE EFFECTS OF GENES ON ANTISOCIAL BEHAVIORS

This week's issue of the journal Science reports that a variant of a gene in the brain that produces the enzyme monoamine oxidase A (MAOA) may play a role in the development of antisocial behavior. The study looked at a large cohort of male children who had been abused or otherwise maltreated during childhood. The study volunteers were observed from childhood through adulthood for signs of antisocial behaviors. The authors found that a variant of the MAOA gene that causes increased levels of this enzyme in the brain was, in fact, associated with a significantly lower incidence of aggressive-and other antisocial-behaviors. MAOA breaks down several neurotransmitters in the brain, and MAOA inhibitors were once the most commonly used class of drugs used to treat depression before seretonin reuptake inhibitors (e.g., Prozac) came along.

This study suggests that genetic traits can potentially modify a person's response to certain environmental conditions, and to an abusive environment during childhood in particular. It also suggests potential therapeutic strategies for at least some cases of abuse-related antisocial behavior. This, of course, raises complex social and ethical issues, but such issues are bound to arise more frequently as additional discoveries linking human biology and behavior occur.

JWR contributor Dr. Robert A. Wascher is a senior research fellow in molecular & surgical oncology at the John Wayne Cancer Institute in Santa Monica, CA. Comment by clicking here.

Up

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07/12/02: A cancer surgeon's perspective on hormone replacement therapy

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06/28/02: Antioxidants & the Risk of Alzheimer's Disease; Effects of Exercise on the Hearts of Patients with Mild Hypertension; Statins reduce cardiac events following angioplasty; more

06/21/02: Sex & violence and Advertising: Do Advertisers Get What they Pay For?; Don't Drink the Water (or the Salsa Either!); Vasectomy & Prostate Cancer Risk; Update on Smoking & Disease

06/14/02: Young Men, Obesity & Heart Disease; Breastfeeding & Obesity; Irritable Bowel Syndrome & rectal pain threshold; more data on cox-2 inhibitors & cancer; more

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05/24/02: Molecular detection of tumor cells in the blood & prognosis; Cox-2 & breast/lung cancers; BRCA2 gene mutations & the risk of breast cancer; breast density & the risk of breast cancer

05/19/02: Moderate alcohol intake and blood sugar levels; more good news for tea drinkers; blood potassium levels & the risk of cardiovascular disease; ethnic differences in diabetic complications

05/10/02: Tea drinkers and the risk of death following heart attack; duration of breastfeeding & adult intelligence; abdominal aortic aneurysms: surgery or observation?

05/03/02: Risk of adverse drug reactions from newly released medications; preoperative beta-blockers may reduce heart bypass deaths; shape-shifting plastics may alter surgical practice; weight loss supplement may cause liver damage
04/26/02: Angry young men & risk of premature cardiovascular disease; stay-at-home dads & risk of cardiovascular disease; more on the effects of statins; dairy consumption and the risk of pre-diabetes; smallpox vaccine: good to the last drop?
04/19/02: Change your sex by drinking water?; Anti-inflammatory RXs may reduce growth of breast cancer cells; radiation treatment reduces repeat narrowing of bypass grafts
04/05/02: Fish & Omega-3 fatty acid consumption and cardiac health; news briefs
04/05/02: Can coffee reduce your risk of tooth decay?; exercise & blood pressure; a single high-fat meal reduces coronary artery function
04/01/02: Pre-diabetes: a newly defined category of health risk; teen television viewing and subsequent aggressive behavior; the benefits of strength training in the elderly; more ...
03/22/02: Bacteria, antibiotics & heart disease; mammograms: the debate continues; calcium & the risk of colon cancer ... and more
03/15/02: Mammography debate continues; statins & fracture risk; physical fitness & the risk of death; other intriguing findings
03/08/02: Blows to the chest & sudden cardiac death; air quality & the risk of lung cancer; tomatoes and your prostate
03/01/02: Diet & the risk of ovarian cancer; lifetime risk of developing high blood pressure; Osteoporosis prevention with a once-a-year injection?
02/26/02: The continuing controversy regarding screening mammography
02/22/02: Lowering body temperature after heart attack improves outcome; A silver lining for the chronically sleep-deprived?
02/15/02: Hormone replacement therapy & the risk of breast cancer; use it or lose it: Alzheimer's disease & cognitive stimulation; stress, divorce & death; child daycare, infections & parental guilt
02/08/02: Possible breakthrough in early cancer diagnosis; mammography: the controversy continues; CPR techniques revisited
02/01/02: Antibiotics in livestock feed & human disease; genetic detection of early colon cancer in the stool; genetic analysis of breast cancers may help decide treatment
01/25/02: Drug increases lifespan (if you're a fly...); workplace attitudes and smoking cessation; effects of inadequate sleep on surgeons
01/18/02: Lifelong effects of premature birth; smokers under the knife; aspirin and cardiovascular health
01/11/02: Estrogen levels in the blood & breast cancer risk; Heart attack: sex and survival; dangerous lettuce invaders
01/09/02: Cancer & aging: Two sides of the same coin?
01/04/02: Vitamin a & the risk of hip fracture in postmenopausal women; ovarian cancer risk and oral contraceptives
12/28/01: Magnetic Resonance Imaging (MRI) detects coronary artery disease; new development in obesity research; adverse childhood experiences & the risk of suicide attempts
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12/07/01: Update on school shootings; new implantable heart-assist device approved for further evaluation; prevention of fungal infections in pre-term babies
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11/21/01: Modified smallpox vaccine may reduce risk of cervical cancer; New approach to breast cancer diagnosis; New non-invasive prenatal diagnostic test for down's syndrome
11/16/01: Cholesterol-lowering drugs reduce risk of heart attack; supplemental radiation therapy reduces risk of breast cancer recurrence; brains of women may answer age-old questions
11/09/01: Bio-warfare (redux); my gray matter is bigger than yours; mad elk disease?
11/02/01: Making sense of bio-warfare
10/26/01: The impact of mammography on deaths due to breast cancer; diet & exercise may slow cancer cell growth; antidepressants and the risk of heart disease
10/19/01: New insights into autism; the wiley appendix
10/12/01: More bad news about obesity links to other diseases…Hey dad, can I borrow the car keys?
10/05/01: California leads nation in reduction of tobacco-related disease; exercise as an antidepressant?
09/25/01: Advances in the detection of breast cancer; primary care physician awareness of peripheral arterial disease; arsenic in the water
09/17/01: In perspective
09/12/01: Genes may hold secret to long life; men and women: cognitive function in the elderly; physical activity, obesity and the risk of pancreatic cancer
09/05/01: English milk cows prefer Beethoven and Simon & Garfunkel over Bananarama; new prostate cancer prevention study: looking for a few good men; exercise & diet can help prevent diabetes
08/28/01: Arthritis drugs may be linked with increased risk of heart disease; errors in blood clotting tests can be fatal; infant soy formula not associated with reproductive side effects

© 2002, Dr. Robert A. Wascher