Jewish World Review Oct. 26, 2001 / 9 Mar-Cheshvan, 5762




The impact of mammography on deaths due to breast cancer

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

http://www.jewishworldreview.com -- THE current issue of the Lancet contains what is certain to be a controversial study from Denmark. The authors of the paper report on their review of multiple breast cancer studies published to date, and conclude that there is no evidence in those studies that confirms the commonly held view that screening mammography reduces deaths due to breast cancer.

The same authors ignited a firestorm of controversy in the medical community last year when they published similar findings on a preliminary basis. Their conclusions, based upon a retrospective analysis of previously reported studies, have generally been rejected by most breast cancer experts around the world.

These experts note that many studies have shown that, in communities that widely employ screening mammography, breast cancer is diagnosed when the tumors are generally smaller and, hence, less likely to have spread. Moreover, as screening mammography has become more common in developed countries over the past 10 years, the death rates for breast cancer have actually decreased, despite the increased number of cases diagnosed in each successive year.

It is also important to recognize that this controversial report is based entirely on a retrospective analysis of studies performed by other researchers. Indeed, this report, which questions the value of mammography, is related more to the perceived scientific weaknesses of these previous studies than to any new data that suggests that mammography is ineffective in the battle against breast cancer.

Another related issue that is not well covered in the Lancet paper is that millions of women around the world have been able to undergo breast-conserving surgery due, in great part, to the mammographic detection of tumors that are still quite small.

It will likely require large multicenter studies, involving thousands of study volunteers, to put this controversy to rest. Meanwhile, virtually all cancer specialists continue to urge women to obtain annual screening mammograms if they fall into the currently recognized age or family history risk categories.

DIET & EXERCISE MAY SLOW CANCER CELL GROWTH
Evidence that a healthy diet and moderate exercise may reduce the risk of certain cancers continues to accumulate. A new study, as reported by UCLA researchers in the Journal of Urology, suggests that moderate exercise and a low fat/high fiber diet may actually slow the growth of prostate cancer tumors.

The blood of patients engaged in such healthy lifestyle interventions, when added to prostate cancer cells growing in a culture plate, suppressed the growth of tumor cells by 30-40%. However, the addition of blood from patients who did not exercise or watch their diet had no effect on tumor cell growth. Loss of excess weight, and long term continuation of exercise and good eating habits, appeared to have an additive effect on slowing tumor cell growth!

ANTIDEPRESSANTS AND THE RISK OF HEART DISEASE
The journal Circulation has just published an intriguing study on the effects of the seretonin reuptake inhibitor (SSRIs) antidepressant drugs on the incidence of heart disease in smokers. In this study, smokers taking SSRIs (Prozac is an example of this class of drugs) had just one-third the incidence of heart attack as smokers who were not taking SSRIs.

The authors note that there are at least two possible explanations for this observation. First, chronic depression is known to increase the risk of heart attack, and the treatment of depression could, therefore, reduce this risk factor. Secondly, the SSRIs may reduce the activity of platelets in the body. These blood cells are responsible for forming blood clots, and drugs that "thin" the blood (including aspirin) are known to reduce the risk of heart attacks and strokes by reducing platelet activity in the blood.

Of course, smoking is the single greatest preventable risk factor for heart attacks and strokes!

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

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

© 2001, Dr. Robert A. Wascher