Re: No increase, or less, cancer after I-131 treatment of hyperthyroidism

[Muckerheide <muckerheide@mediaone.net>]

I-131 hyperthyroid therapy dose to whole body, vs. thyroid cancer from
diagnostic I-131
 
"Björn Cedervall" wrote:
> 
> Just a comment: The L-E. Holm studies on I-131 and treatment for
> hyperthyroidism (from around 15-20 yrs ago) concerned only adults. I think
> that it is always important to make this distinction. I have seen a "green"
> discussion about childhood thyroid cancer and then refs. to L-E. Holm's work
> (to downgrade it) without a proper note about the child/adult difference.
> Did Dr. R. Yalow publish any research studies on the risks of I-131 BTW (did
> I miss any references?)?
> 
> bjorn_cedervall@hotmail.com


Hi Björn, Group,

However, the data was about whole-body/bone marrow dose (from
hyperthyroid treatment, 10-80 cSv) vs (NO excess) cancer/leukemia
(contrary to LNT). There was nothing about Holm's (and others) studies
of (the lack of) thyroid cancer from I-131 diagnostic treatments (~50cGy
and up to the thyroid).


However, Holm (1991) does address higher thyroid cancer risk in children
<5 years in:
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=1750277&form=6&db=m&Dopt=b

More recently, 1996, in Rad Res, Holm with Hall and others find no
difference in women <20 vs. >20 years:
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=8955718&form=6&db=m&Dopt=b

Also in 1996, Rad Res, Hall reported on a mean dose of 1.1 Gy that
persons not diagnosed for a thyroid tumor had no excess (also a
decrease? I haven't seen the full paper), with a "slight" increase in
<20 years (3 vs 1.8 Exp):
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=8532842&form=6&db=m&Dopt=b

In 1988, in J Natl Cancer Inst, Holm also reported on 35,000 I-131
patients, 5% <20 years. There was excess thyroid cancer primarily in the
high-dose group (>75cGy). But for patients NOT diagnosed for a suspected
thyroid tumor, the thyroid SIR was 0.62:
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=3411626&form=6&db=m&Dopt=b

See also a less definitive study in France by Schlumberger and De
Vathaire, 1996, Ann Endocrinol (Paris):
http://www.nytimes.com/yr/mo/day/letters/lcrisp.html

Another more recent assessment of head and neck x-rays vs. thyroid
cancer that shows no effect is by Inskip, 1995, J Natl Cancer Inst:
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=7563204&form=6&db=m&Dopt=b
[if anyone has access to this journal/paper, it would be interesting to
know whether they estimate the doses, and whether the negative
relationship is significant instead of 'doesn't show positive'!?]

And one of the recent studies of thyroid nodules and cancers on
Chernobyl workers is for 2000 workers from Estonia, with an est. 10.8
cGy mean dose, (and NO adverse effects), is also by Inskip et army,
1997, Radiat Res.
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=9008215&form=6&db=m&Dopt=b

This could go on, but... :-)

Regards, Jim Muckerheide
muckerheide@mediaone.net
Radiation, Science, and Health
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