Jewish World Review Dec. 14, 2001 / 29 Kislev, 5762




Chernobyl and the Risk of Thyroid Cancer in Children

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

http://www.jewishworldreview.com -- THE current issue of the journal Lancet reports on a study of 21,601 children living within a 90-mile radius of the Chernobyl nuclear power plant. The Chernobyl plant accident occurred on April 26, 1986. Among 9,472 children conceived and born between 1987 and 1989, there were no cases of thyroid cancer. However, there was one case of thyroid cancer among the 2,409 children of mothers who were pregnant at the time of the accident, or shortly thereafter. More strikingly, there were 31 cases of thyroid cancer diagnosed among the 9,720 children born in the three years prior to the accident, and who were, therefore, young children on the day that Chernobyl self-destructed.

These findings of a relationship between the Chernobyl accident and increased rates of thyroid cancer in children living nearby are significant, as the radioactive iodine molecules that result from the fission reactions that power both nuclear reactors and nuclear weapons are known to cause thyroid cancer. Radioactive iodine is selectively concentrated in the thyroid gland, where it can cause mutations that lead to cancer. The radioactive iodine molecules, however, have a very short half-life (1 to 8 days, depending upon the "species" or "isotope" of iodine).

Thus, it is not surprising that the children who were still in their mothers' wombs were at mildly increased risk of exposure to Chernobyl's fall-out, while the children born before the accident sustained much greater exposure. However, children born 1 or 2 years after the melt-down were at no apparent increased risk of developing thyroid cancer, as the radioactive iodine had decayed into non-radioactive forms by then (although the risk of lymphomas and leukemias may still be increased for this latter group, as longer half-life radioactive molecules are also created by fission reactions).

Except for a few uncommon genetic syndromes, thyroid cancer is extremely rare in young children, and particularly since radiation treatment for benign conditions, such as facial acne, was discontinued in the early 1960s. In cases where exposure to nuclear fission byproducts is anticipated, one can take large doses of non-radioactive iodine, thus flooding the thyroid gland with as much iodine as it can absorb. However, the trick, of course, is knowing in advance that you are about to be exposed to radioactive fall-out....

CHILDREN & OBESITY

This week's Journal of the American Medical Association features a report on trends in childhood obesity in the United States. It is known that the number of overweight adults has increased by more than 50% over the past 10 years in this country. The authors of this study evaluated 8,270 children, aged 4 to 12 years, from 1986 to 1998. Their findings were striking.

Among African American, Hispanic and non-Hispanic white children, the percentage of overweight children increased significantly between 1986 and 1998. By 1998, 22% of African American kids were overweight, as were 22% of Hispanic kids and 12% of non-Hispanic white kids. Moreover, the degree of obesity in overweight kids was greater in 1998 than it was in 1986. Therefore, not only are more kids becoming overweight in our society, but the overweight children are becoming ever more obese at the same time.

The causes of these trends are not difficult to identify, and they apply to overweight adults as well. The availability of inexpensive fatty meals, large "American style" meal portions, and the lack of regular and vigorous physical activity in our "remote control society" all play a role. Also implicated has been the gradual reduction in physical education classes in our children's schools.

The toll of obesity on our society is enormous, as I have mentioned in previous columns. Diabetes, heart and vascular disease, stroke, some cancers and bone/joint disease are all linked to obesity. If obesity and tobacco abuse could be eradicated, the number of people dying from the three most common causes of death (heart disease, stroke and cancer) would be drastically reduced. During this holiday season, try to watch the content and portions in your diet, abstain from tobacco and excessive alcohol intake, and make a commitment to getting some exercise on a regular basis!

GASTROESOPHAGEAL REFLUX DISEASE UPDATE

Most of us know gastroesophageal reflux (GER) by its common term, "heartburn." While all of us who overindulge now and then are familiar with that burning sensation in our lower chest, people with chronic GER are at risk of developing a narrowing of the esophagus due to scarring. In some cases of severe chronic GER, pre-cancerous changes (known as "Barrett's esophagus") can occur, and can lead to cancer of this tube-like organ that propels food from our mouths down to our stomachs. Until recently, the treatment of chronic GER has relied upon medications that suppress acid production or surgery.

For most patients who undergo surgery, the operation is designed to recreate the high-pressure zone that they have lost at the junction of the esophagus and the stomach. A floppy portion of the upper stomach is wrapped around the lower esophagus, and the hole in the diaphragm where the esophagus passes through, into the abdomen, is tightened with sutures. Until recently, this operation required a large abdominal incision, and several weeks of recovery time. However, most of the time, this operation is now performed laparoscopically (i.e., through several small incisions, using special instruments and a video camera). Even the laparoscopic operation, however, carries many of the risks of the previous "open" abdominal operation.

The journal Gastrointestinal Endoscopy recently reported on a promising new technique for restoring the high-pressure zone in the lower esophagus. The new procedure uses a flexible tube, called an endoscope, that is passed through the mouth and into the esophagus. High-frequency radio waves are then used to "tighten-up" the lower esophagus. One year after the procedure, 66% of the 118 patients in this study were off of all of their GER medications.

This interesting study of a new anti-GER procedure needs to be further studied in order to assess its true effectiveness, the duration of its effects, and the incidence of complications. However, it may someday offer chronic GER patients another option for minimally invasive treatment.

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.

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© 2001, Dr. Robert A. Wascher