Re: A dose of reality, continued

["Sandy Perle" <sandyfl@earthlink.net>]

Peter Crane posted the following:

> 4.  493 childhood thyroid cancers in Belarus alone (the study in the
> American Cancer Society journal was based on that number of cases) is a
> whopping number.  My understanding is that in Russia, Belarus, and
> Ukraine combined, the total of childhood thyroid cancers now exceeds
> 2000 cases.  Is it your claim that this represents no more than three or
> four times normally expected rates? 

This is one of the articles I mailed to my news distribution list on 
March 15. It supports Peter's comments:

Wednesday March 15 7:09 PM ET 

Radiation hits very young the hardest  

NEW YORK, Mar 15 (Reuters Health) -- Exposure to radiation, such as 
that released by the Chernobyl nuclear plant accident, takes a 
heavier toll on very young children, according to new study findings. 

 Among children living in Belarus, thyroid cancer was more common and 
more severe in children who were younger than 2 years old at the time 
of the 1986 accident than in those who were older, researchers 
report. In addition, the rate of childhood thyroid cancer was 
considerably higher in girls than in boys.  

Radiation released by the nuclear accident at Chernobyl led to an 
increased rate of thyroid cancer in children living in regions 
surrounding the plant. Previous research has shown that younger 
children were at greatest risk of developing cancer, but whether or 
not a child's age affected the severity of the disease has not been 
studied closely, according to a team of researchers led by Dr. 
Jamshid Farahati, of the University of Wurzburg in Germany.  

In the current study, the research team looked at 483 children with 
thyroid cancer who were living in Belarus at the time of the 
accident. All of the children were younger than 8 years old when 
exposed to radiation from the plant.  

As has been reported before, the greatest number of cancer cases 
occurred in children who were younger than 2 years old at the time of 
the accident, Farahati and colleagues report in the March 15th issue 
of Cancer, a journal of the American Cancer Society. The 
investigators also found that the rate of cancer was 60% higher in 
girls than in boys.  

But the researchers note that cancer tended to be more severe in the 
youngest children. In youngsters under age 2, tumors had grown 
outside the thyroid gland 62% of the time, compared with just 40% in 
children aged 6 to 8 years old. In addition, the youngest children 
were more likely to have cancer spread to the lymph nodes and other 
parts of the body, according to the report. But despite the 
differences in disease severity, the lag time between radiation 
exposure and cancer diagnosis was similar in all children.  

The authors explain that thyroid cells in infants and toddlers divide 
rapidly as the glands mature. Since cancer depends on mutations that 
occur during cell division, each time a cell divides is an 
opportunity for cancer to take hold. In contrast, older children have 
more mature thyroid glands, so the pace of cell division is slower, 
which may explain in part why the risk of thyroid cancer is lower in 
older children. And since thyroid glands in younger children tend to 
be smaller than in older kids, the same amount of radiation may have 
more of an effect, leading to more severe cancer, according to the 
report.  

After an average of nearly 4 years of follow-up, none of the children 
had died from cancer, Farahati and colleagues report. However, they 
state that these children should continue to be followed to see what 
effect, if any, age at the time of radiation exposure has on long-
term survival. SOURCE: Cancer 2000;68:1470-1476.

------------------------------------------------------------------------
Sandy Perle					Tel:(714) 545-0100 / (800) 548-5100   				    	
Director, Technical				Extension 2306 				     	
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